half a century celebrating in edinburgh

SCOPECorrecting interruptions in

radiotherapy treatment

Book now for ICMP2013

Medical equipment in

developing countries

Half a centuryCelebrating in

Edinburgh

INSTITUTE OF PHYSICS AND ENGINEERING IN MEDICINE | www.ipem.ac.uk | Volume 21 Issue 2 | JUNE 2012INSTITUTE OF PHYSICS AND ENGINEERING IN MEDICINE | www.ipem.ac.uk | Volume 22 Issue 2 | JUNE 2013

P08 QA MAKES TRIAL STRONGEREvidence-based medicine inradiation therapy for clinical trials

P21 ULTRASOUND MEASURINGUsing an ultrasound method toestimate muscle volume in vivo

P53 ATOM LEAK COVER-UPThe incident according to the DailyExpress in January 1984

CONTENTS

SCOPE | JUNE 2013 | 03

THIS ISSUE11 Cover feature: Half a century of clinical bioengineering

The major milestones of the service in Edinburgh as itcelebrates the 50th anniversary of its establishment

18 To correct for interruptions in radiotherapy treatmentsMethods to correct for missed treatment days duringradiotherapy, calculating advantages and disadvantages

21 Estimating muscle volume using ultrasoundUsing ultrasound, rather than conventional MRI or CTtechniques, to measure muscle volume in vivo

26 ICMP2013: booking open for a visit to BrightonThe International Congress on Medical Physics in Brightonis open for abstract submission and booking

28 Medical equipment in AfricaAn innovative new programme to improve the maintenanceand management of equipment in developing countries

53 Covering-up a great atom leak: tabloid scare storiesThe ‘radiation leak’ incident as it happened, according to theDaily Express on 19th January 1984

29 12th Congress of the European Association ofThermology (EAT)John Allen

33 PET neuroimaging research in the US: a 3-week researchvisitTherese Soderlund

37 Research and Development in 3D Radiation DosimetryA.L. Palmer

40 IMRT Verification Meeting: making the most of itCatharine Clark

42 Radiological Society of North America (RSNA) AnnualMeetingJonathan Taylor

45 12th International Conference on Electronic PatientImaging (EPI2K12)Leila Nichol

04 President’s letter Innovation, innovation

05 CEO’s column Recommended procedures

06 Editor’s comment Crowd sourcing

07 News Stories in the headlines from across the globe

48 Book reviews With an urgent request for more reviewers

REGULARS

MEETING REPORTS

FEATURES

HISTORICAL FEATURE

11

26

29

42

PRESIDENT’S LETTER

t is hard to ignore the message that ‘innovation’ is theonly method by which the health service will besustainable into the future. NHS England haspropounded the Innovation, Health and Wealthagenda linking the country’s economic success to

innovation in health. This has resulted in large sums ofmoney being invested to support this agenda includingagencies aimed at supporting the innovators and thecommercialisation of their ideas. All the major science andtechnology grant funding bodies have a large proportionof their funds dedicated to health-related topics. Networkconcepts have proliferated within the health communityseeking to bring together health professionals, academicsand technology companies to deliver on this agenda.Furthermore commercial and consulting companies nowhover around the health community seeking to captureideas and funding in a way never seen before. The healthcommunity seeks to collaborate to minimise the economichardship that many institutions face. Finding a waythrough this landscape is often a daunting problem forthe hospital-based clinical scientist, whether physicist orengineer, and yet I do believe that they are well placed tomeet the challenge of the innovation agenda. Withcolleagues the ‘unmet clinical need’ can be identified andpossible solutions taken from idea to prototype. Theexpertise on how to take an idea from the academiclaboratory to the patient bedside often resides within ourcommunity and is often overlooked and not understoodby our academic colleagues. A number of departmentshave in place quality systems and resources that allowthem to design, manufacture and CE mark products foruse with patients. Scaling up from ‘one bedside’ to ‘manybeds’ or implementing ideas within a wider community isoften much more challenging and will often requiresignificant investment. It is clear many ideas never makeit to the marketplace because they are not seen as‘commercially viable’. In the patient arena and in the age

of personalised medicine I do notbelieve this should be seen as an

impediment to thedevelopment of ideas

and products asopposed to

profit.

This year sees the 7th anniversary of the formation ofthe National Institute for Health Research (NIHR). Withresources aimed at supporting research and innovationwithin the health community there is every opportunityfor all healthcare scientists to link to key researchinitiatives and to seek funding for novel ideas. Inaddition, funding to undertake PhD programmes postqualification is regularly available and should not beoverlooked by newly qualified clinical scientists.

Health Technology Co-operatives

The NIHR has recently funded the development of eightHealth Technology Co-operatives. These have been builtupon two successful pilots, one of which has been‘Devices for Dignity (D4D)’ run by Wendy Tindale. Thechosen themes address areas of high morbidity andunmet need for NHS patients and healthcare technologyusers. These co-operatives have funding for 4 yearscommencing January 2013. One of their primary aims is toact as a catalyst for the development of new medicaldevices, healthcare technologies and technology-dependent interventions. They are charged with bringingpartners together to develop, test and improve productconcepts leading to clinical evaluation and demonstratedpatient benefit. The key areas include brain injury, traumamanagement including rehabilitation, cardiovasculardisease, devices for dignity, colorectal therapies andwound prevention and treatment. IPEM members areinvolved in a number of these programmes and I wouldencourage anyone with an idea to contact a relevantgroup to gain advice and even seek funding todemonstrate proof of concept. Local circumstances andinfrastructure should not be an impediment to gainingadvice and support on taking an idea forward. Furtherinformation can be found atwww.nihr.ac.uk/infrastructure/Pages/HTCs.aspx.

As healthcare scientists at all levels our potential lies inour ability to further apply science and engineering forthe benefit of patients. We cannot and should not becontent with the status quo. The IPEM will again this yearinvest £50,000 to support the pump priming of novelresearch and provide yet another opportunity formembers to take forward their ideas.

In closing I want to encourage you to attend the ICMPconference from 1st to 4th September 2013 in Brighton.This will form the IPEM Annual Conference for 2013 aswell as the European and IOMP conferences for 2013. Thisis a rare opportunity to participate in an internationalmedical physics and clinical engineering conferencewithout leaving the UK. Registration and further detailsare available at www.icmp2013.org.uk.

Innovation, innovation

IPETER JARRITT

President

The time toinnovate is now▼

Peter Jarritt suggests that innovation is happening throughout the

healthcare system and encourages forward thinking in research

CEO’S COLUMN

he Final Report of the Independent Enquiryinto Care Provided by Mid Staffordshire NHSFoundation Trust’ (known as the ‘FrancisReport’), published in February 2013, containsrecommendations that have implications for

all professionals working in healthcare. Some of theserecommendations are specifically for professionalorganisations, and some are aimed at registeredprofessionals. So it was important for IPEM to reviewthese recommendations on behalf of members, and todraw out actions relevant to us as an organisation, and tomembers as individuals.

The Professional Advisory Group (PAG) discussed therelevant recommendations at its meeting in March, andreported back to Council. The areas most relevant toIPEM members are about providing leadership, settingstandards for conduct and practice, measuring qualityand reporting concerns. PAG’s conclusions were thatmany of the actions proposed for professionalorganisations were already being undertaken by IPEM,but that these need to be highlighted and, in some cases,updated for the benefit of members. Specifically: n There is guidance on conduct and practice for IPEMmembers from the Institute’s own Code of Conduct, theCode of Conduct for registrants on the VoluntaryRegister of Clinical Technologists, HCPC standardsfor registered scientists and the Good ScientificPractice document adopted by the Academy forHealthcare Science. These documents have all beenmade more easily accessible via the IPEM website. n There are IPEM policy statements available viathe website which set evidence-based standards forprocedures, interventions andpathways. Some of these arenow due to be updated – thishas beenhighlightedon thewebsite,

and a programme for review is underway. In addition,IPEM is currently in discussion with the Department ofHealth about producing a new set of serviceaccreditation standards for both medical physics andclinical engineering, for the Academy of HealthcareScience. We need to recognise this work as an example ofhow we ensure the quality and safety of services, in linewith our strategic objectives. n As members’ employing organisations have in placeprocedures for reporting concerns, PAG felt that IPEM’srole is to signpost to these, and to organisations whichcan offer direct support to individuals who are fearful ofthe consequences of such reporting. We will put furtherinformation about such organisations on our website formembers. n PAG made the point that, post-Francis, professionalengagement in quality and developmental activitiesmust be actively encouraged and facilitated by allconcerned; whereas at present it is increasingly difficultfor members to be released for this. We will repeat ourcall for this to the Department of Health and others,which rely on volunteer input to achieve their aims, butcould do more to mandate this with the NHS and otheremployers.n The recommendation to identify the qualities of a goodand effective leader is being taken forward through ourwork with the Royal College of Radiologists on thedesign of the Higher Specialist Scientific Training (HSST)programme; we will continue to contribute to this. Thecompetencies required for leadership by scientists arealso present in Good Scientific Practice, and we haveextracted these and posted them in a separate documenton the website.

The Government will be issuing a fuller response tothe Francis Report in the autumn, and we will review

this for any further actions. We will also continue todiscuss this important report with otherprofessional bodies, including the Royal Collegeof Radiologists and Society and College ofRadiography, to identify any issues on which weshould take joint action.

I know that our members are committed to highstandards of practice and conduct and I hope that

these actions will providethem withadditionalsupportandguidance

to deliverthis.

Recommended procedures

T‘ROSEMARY

COOK CBE

Chief ExecutiveOfficer

Effectiveleadershipqualities shouldbe identified

▼

Rosemary Cook CBE reviewed recent recommendations on leadership,

standards and quality and how they affect members at all levels


I know that ourmembers are committed tohigh standards of practice

and conduct““

Scope is the quarterlymagazine of the Institute of Physics and Engineeringin MedicineIPEM Fairmount House, 230 Tadcaster Road, York, YO24 1EST 01904 610821F 01904 612279E [email protected] www.ipem.ac.ukW www.scopeonline.co.uk

EDITOR-IN-CHIEFGemma WhitelawRadiotherapy Physics,Basement, New KGVBuilding, St Bartholomew'sHospital, West Smithfield,London, EC1A 7BEE [email protected]

ASSISTANT EDITORUsman I. LulaPrincipal Clinical Scientist,1st Floor, Radiotherapy,Building, Medical Physics -University, HospitalsBirmingham NHSFoundation Trust, QueenElizabeth Hospital, QueenElizabeth Medical Centre,Birmingham, UK B15 2THT 0121 627 2000E [email protected]

MEETING REPORTS EDITORAngela CottonHead of Non-IonisingRadiation Support, Medical Physics &Bioengineering,Southampton GeneralHospital, Southampton,SO16 3DRE angela.cotton@suht.

swest.nhs.uk

NEWS EDITORSUsman I. LulaPrincipal Clinical Scientist,1st Floor, Radiotherapy,Building, Medical Physics -University, HospitalsBirmingham NHSFoundation Trust, QueenElizabeth Hospital, QueenElizabeth Medical Centre,Birmingham, UK B15 2THE [email protected]

and

Richard A. AmosDepartment of RadiationPhysics, The University ofTexas M.D. Anderson CancerCenter, 1840 Old SpanishTrail,Houston,Texas 77054, U.S.A.T + 1 713 563 6894F + 1 713 563 1521E richamos@mdanderson.

org

BOOK REVIEW EDITORUsman I. LulaPrincipal Clinical Scientist,1st Floor, Radiotherapy,Building, Medical Physics -University, HospitalsBirmingham NHSFoundation Trust, QueenElizabeth Hospital, QueenElizabeth Medical Centre,Birmingham, UK B15 2THE [email protected]

MEMBERS’ NEWS EDITORMatt GwilliamCancer Research UK ClinicalMR Research Group,Institute of Cancer Researchand Royal Marsden NHSFoundation Trust, SuttonSM2 5PTE [email protected]

INTERNATIONAL EDITOR(Developing countries)Andrew GammieClinical Engineer, Bristol Urological Institute,

BS10 5NBT +44(0)117 950 5050

extension 2448 or 5184E [email protected]

INTERNATIONAL EDITOR(North America)Richard A. Amos Department of RadiationPhysics, The University ofTexas M.D. AndersonCancer Center, 1840 OldSpanish Trail,Houston,Texas 77054, U.S.A.T + 1 713 563 6894F + 1 713 563 1521E richamos@mdanderson.

org

CLINICAL TECHNOLOGISTEDITORFrances RyeSenior Clinical Technologist,Department ofRadiotherapy Physics,Poole Hospital NHS,Foundation Trust,Longfleet Road, Poole,Dorset, BH15 2JBT 01202 442307E [email protected]

ONLINE EDITORPosition vacant

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Scope is published quarterlyby the Institute of Physicsand Engineering in Medicinebut the views expressed arenot necessarily the officialviews of the Institute.

Authors instructions andcopyright agreement can befound on the IPEM website.Articles should be sent tothe appropriate member ofthe editorial team. Bysubmitting to Scope, youagree to transfer copyrightto IPEM.

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ISSN 0964-9565

elcome to the summer edition of Scope! You may noticesome interesting new changes this issue. We’ve relocatedsome of the meeting reports to the website to enable us tocreate more space for you! We may not all work at CERNor have played the bongos with Brian Cox but if you’ve

got an interesting tale to tell, we’d like to hear it!We’ve made the room and we want you to fill it. Whether it’s sharing

observations about bad science that you’ve read, or reminiscing aboutmisreported accidents at work (see below), we’d appreciate yourcontribution.Scope is the perfect forum for general interest articles, good research

that might not necessarily be suitable for a journal, reports oncollaborations and projects, trainee projects, historical features, tutorialsand other pieces that would engage the interest of the membership.Support is available for all budding authors. It is always nice to see yourhard work in print and you’ll make your mother proud!

Crowd sourcing seems to be the new way to get things done, so tobuild our proposed new feedback section we’d like to crowd source youropinions on what you’ve read in Scope! Whether you support or disagreewith someone’s viewpoint we want to hear from you.

And on to this edition. Michael Dolan and David Gow lead us on ahistorical journey through 50 years of bioengineering in Edinburgh. Page28 introduces us to an initiative which aims to improve the maintenanceand management of medical equipment in developing countries. We willbe following the progress of this worthwhile and fascinating project insubsequent editions. Also in this issue the highly regarded physicist Jack

Fowler describes strategies to correctfor interruptions in

radiotherapy treatments, amust read for all

radiotherapyphysicists. We round

off with ‘Covering-up a great atomleak: tabloid scarestories’ by W.Alan Jennings, atabloid scandalfrom the 1980s.

I hope that youmay be inspired to

contribute to Scopeeither as feedback or

an article, but if not, Ihope you enjoy reading

it as much as I do!

Crowdsourcing

W

GEMMA WHITELAW EDITOR-IN-CHIEF

06 | JUNE 2013 | SCOPE

EDITOR’S COMMENT

Whether you support ordisagree with someone’sviewpoint we want to hear

from you“

“


Improving detection of myocardial ischaemia

Researchers at MassachusettsGeneral Hospital (MGH) havedeveloped a new reconstructionalgorithm that reduces twosignificant sources of artifact incardiac PET scans, and couldsignificantly improve the detectionof myocardial ischaemia. In a

study the algorithm demonstrated

up to 235 per cent greater

sensitivity than conventional

reconstruction approaches.

Movement of the heart through

both the cardiac and respiratory

cycles and the partial volume effect

(PVE) are two significant sources of

PET image degradation. Cardiac

motion produces blurring and

attenuation artifacts, whereas PVE

smears photon counts around the

true location of tracer uptake.

Cardiac gating is one method of

reducing motion artifacts, but the

extraction of counts from

individual cardiac phases and

rejection of counts from other

phases results in a low signal-to-

noise ratio (SNR). Alternatively,

motion-corrected PET identifies

counts from each location in the

myocardium over all cardiac

phases, combining them in a

single image with a significantly

higher SNR. The team at MGH

used the latter approach,

correcting for motion using

tagged MRI, acquired

simultaneously with PET data on

a hybrid PET/MRI scanner.

The motion data were

incorporated into the system

matrix of an existing list-mode

PET ordered subset expectation

maximisation (OSEM)

reconstruction algorithm. The

system matrix models the count

acquisition process and by

incorporating the MRI-derived

motion data, the model accuracy is

improved, as is the quality of the

reconstructed image.

PVE artifacts were reduced by

incorporating a model of the

detector’s point spread function

(PSF) – the detector’s response to a

point radioactive source – into the

system matrix. The modified matrix

acts like an iterative deconvolution

process during image

reconstruction, filtering out the

detector response from the

reconstructed image and

improving image resolution.

The modified algorithm was

tested against gated and non-

motion-corrected PET using a

deformable phantom that

simulated cardiac motion, and

areas of ischaemia and reduced

perfusion. Qualitative

improvements in perfusion defect

visibility were clear, particularly

when PET and MRI images were

NEWS BY USMAN I. LULA AND RICHARD AMOS

CARDIAC IMAGINGfused. SNRs were used to

quantify lesion detectability.

Imaging using the new MRI

motion correction outperformed

other approaches convincingly,

by 115–136 per cent compared

with gated imaging and by 62–235

per cent compared with non-

motion-corrected imaging over

three lesion sizes. When the PSF

model was included in the

reconstruction algorithm, lesion

detectability increased by a

further 39–56 per cent.

In ongoing work, the

researchers have extended the

algorithm to correct for

respiratory motion and are

testing it in vivo in animal models

and patients.

Intra-fractional volumetric imaging

Researchers at StanfordUniversity in California have useda new cone-beam CT (CBCT)technique to image soft tissueanatomy in a lung cancer patientduring respiratory gatedvolumetric-modulated arctherapy (VMAT). Using a relatively

small number of kilovoltage (kV)

x-ray projections and a non-

standard reconstruction

algorithm the technique has

potential applications that include

treatment delivery verification and

the reporting of cumulative dose.

Using an on-board imager, 20

to 40 projections are acquired

from a 360-degree arc around the

patient during treatment. Using a

smaller number of projections

than is typical for conventional

CBCT, dose to the patient is

limited. The respiratory gating

signal triggers both the kV

projection and the megavoltage

(MV) treatment beam, with the

image data being acquired

immediately prior to delivery of

the treatment beam. This

approach achieves intra-

fractional imaging while avoiding

any contamination of the images

with scatter from the MV

treatment beam.

The researchers developed a

new reconstruction algorithm to

compensate for the

undersampling of the patient

anatomy compared to

conventional CBCT. The fast

iterative shrinkage/thresholding

algorithm with line search

(FISTA-LS) is a fast first-order

algorithm that uses a

compressed sensing approach

which is effective at

reconstructing images from

sparsely sampled data.

The technique was used to

image a thoracic phantom that

mimicked respiration and one

lung cancer patient receiving

VMAT treatment. Images

generated using the FISTA-LS

algorithm were compared to

those reconstructed with a

Feldkamp–Davis–Kress (FDK)

algorithm, as used for

conventional CBCT

reconstruction.

Soft tissue structures could be

discerned in the images produced

by this technique. The FISTA-LS

algorithm performed better than

the conventional FDK algorithm,

which produced significant

streaking artifacts in both the

phantom image (figure 1) and the

patient image (figure 2).

Quantitative comparison using

a contrast-to-noise ratio (CNR), a

measure of the treatment target

contrast compared to the image

background, revealed that images

generated using the FISTA-LS

algorithm had a target contrast

two to three times greater than

the FDK algorithm.

The researchers are now

investigating ways to improve in

vivo image quality. A clinical

evaluation on a larger patient

cohort is also being planned.

IMAGE-GUIDED RADIOTHERAPY

‘ MORE INFORMATIONThis paper was published in PhysMed Biol 2013; 58: 2085.http://dx.doi. doi:10.1088/0031-9155/58/7/2085

‘ MORE INFORMATIONThis paper was published in MedPhys 2013; 40: 040701.http://dx.doi.org/10.1118/1.4794925

Figure 1. Superior images of athoracic phantom were obtainedwith the FISTA-LS reconstruction(right) algorithm compared to theconventional FDK algorithm (left)

Figure 2. Image quality was lowerin the in vivo images, though theFISTA-LS algorithm (right) still performed better than the FDKalgorithm (left)

n HOLOGRAPHIC IMAGES

Scientists have developed a way

to image living cells and track

their reaction to stimuli, without

requiring contract dyes or

fluorophores. It combines

holographic microscopy with

computational image processing

to obtain 3D images in a few

minutes with a resolution of less

than 100 nm. The resulting

image can then be virtually

‘sliced’ to expose internal cell

elements (Nat Photonics 7: 113).

n NITROGEN-COOLED MEG

Researchers are developing a

MEG system simple and cheap

enough to be available in every

hospital. The new ‘Focal MEG’

technology is based on sensors

that work at –196°C and can be

cooled with liquid nitrogen. Less

insulation is required between

the sensors and the head,

allowing closer placement to the

brain and higher resolution

recording of brain activity (Appl

Phys Lett 100: 132601).

n ADDITIVE MANUFACTURE

Production of complex multi-

pinhole SPECT collimators can

be labour intensive, expensive or

sometimes impossible.

Researchers have examined a

rapid collimator construction

technique called metal additive

manufacturing, which involves

building up the collimator in

layers, using selective laser

melting of tungsten powders at

locations defined by the CAD

design file as solid material (Med

Phys 40: 012501).

n COMPACT X-RAY SOURCE

A team has invented a compact

radiation source that could be

used to create low-cost, portable

x-ray scanners. The device uses

a piezoelectric crystal (lithium

niobate) to produce more than

100,000 V of electricity from only

10 V of electrical input. Such low

power consumption could allow

it to be fuelled by batteries (IEEE

Trans Plasma Sci 41: 106).

Recent RT trials have becomemore comprehensive and labourintensive requiring substantialhuman and financial resources.QA is necessary to ensure

treatment is safely and effectively

administered. QA warrants that

the uncertainty in the dose

delivered to the patient, associated

with each step in the process of

tumour delineation, treatment

planning, including data transfer

and RT delivery within a

prospective trial, is kept

reasonably low and that the RT

deviations will not corrupt the

overall results of the trial.

This systematic review by

Weber et al. assesses the impact

of RT protocol-deviations on a

patient’s outcome in prospective

phase II–III RT trials and the

necessity of performing QA within

prospective clinical trials.

Fifty-five studies were

identified using popular databases

and these studies were filtered

further to exclude items such as

review papers, guidelines, audits

and meta-analysis to nine eligible

phase II–III studies to be used for

this systematic review. For this

review, prospective QA analysis or

interventional QA review was

defined by any review of the

patient-specific QA data

performed before the end of the

first week of RT. In prospective QA

analysis, feedback from the QA

team was given back to the

institutions to recommend

modification of the treatment,

should the plan be non-compliant.

Revised plans were subsequently

further assessed and, if necessary,

additional changes recommended.

RT deviations were rated into

those in which the deviations were

predicted to have a major adverse

effect on tumour control

probability, toxicity or both from

those that might be considered to

be compatible with a reasonable

standard of care (table 1, opposite).

The rates of RT major deviations in

prospective trials are substantial,

ranging from 11 per cent to 48 per

cent (table 2, opposite). The

number of accrued patients per

centre has been significantly

associated with the quality of the

delivered RT within a prospective

protocol, with a cut-off ranging

from 10 to 20.

In one large phase III trial of

advanced head and neck cancers

performed in 81 centres using

prospective and interventional QA,

the estimated local-regional

failure and overall survival were

similar for those patients with

compliant RT plans ab initio and

those plans made compliant by the

interventional QA review.

Of all the studies assessing the

impact of protocol delinquency on

quality of RT, five studies

undisputedly show that non-

adherence to protocol-specified

RT requirements do have a

detrimental impact on a patient’s

outcome. Effect on outcome has

been found to be associated with

reduced survival, local control and

potentially increased toxicity. Non-

protocol compliant RT in clinical

trials may waste time, effort and

money and could, more

importantly, harm patients. The

rate of major deviation can be

substantially improved with the

implementation of prospective and

interventional QA approaches.


QA makes a radiotherapy clinical trialstronger: evidence-based medicine


RADIOTHERAPY PHYSICS

‘ MORE INFORMATIONThis work was published in the GreenJournal: Radiother Oncol 2012; 105:4–8. http://dx.doi.org/10.1016/j.radonc.2012.08.008

Editor’s note: National andinternational trials involving RTrequire detailed implementation by anMPE and draw on resources of thegeneral RT staffing. The initial set-upand maintenance of clinical trials isestimated as one WTE clinicalscientist required for every eightclinical trials (IPEM, 2009) though thisdoes depend on the complexity of eachtrial and the extent of physics input.

Refer also to the recent ReviewArticle in the BJR (86), 2013, titled'Improving radiotherapy qualityassurance in clinical trials:assessment of target volumedelineation of the pre-accrualbenchmark case', presented on behalfof the NCRI RTTQA Outlining andImaging Subgroup. This articleaddresses methods to reduceinterobserver variation in clinicaltrials and how to conduct anassessment of outlining through apre-accrual benchmark case.



TABLE 1

Study [ref.] Years of randomisation Major deviations (tumour) Major deviations (normal tissues)

HD 4 [5]

HD 7 [9]

HD 10 – HD 11 [7]

EORTC 20884 [2]

RTOG 0411 [4]

RTOG 9704 [1]

RTOG 0022 [8]

TROG 0202 [15]

1988–1993

1994–1998

1998–2002

1989–2000

2005–2006

1998–2002

2001–2005

2002–2005

• Excessive or incomplete tumour coverage by radiation

• Total dose <90% or >110% of the prescribed dose

• Dose administered too slowly

• Technical deficiency

• Deviation in the target volume delineation in a primary involved region

• 90% isodose surface not encompassing the planning target volume

• Total delivered dose of ±10% of the prescribed randomised dose

• Overall treatment time exceeding the normal treatment time by 10%

• Omission or partial irradiation of an originally involved region

• 90% isodose surface not covering the target volume

• Inability to delineate gross tumour volume

• Dose delivered not within ±10% of the prescribed dose

• The prescription criteria for PTV66 are not met: 60 Gy isodose does not

cover ≥90% of PTV66. Also the 72.6 Gy isodose surface covers >25% of

PTV66

• The prescription criteria for PTV60 and PTV54 are not met: 47 Gy isodose

surface does not cover ≥99% of PTV54 and the 54 Gy isodose surface does

not cover ≥90% PTV54. The 52 Gy isodose surface does not cover ≥90% of

PTV60 and the 72.6 Gy isodose covers >20% PTV54 and PTV60

• Dose per fraction <2 Gy

• Gross disease treated <66.6 Gy

• D10% <66.5 Gy or >75 Gy (PTV)

ND

ND

ND

• Contoured gross tumour volume >5 cm

greater than the actual tumour size on the

basis of diagnostic imaging

• Use of block margins >5 cm

ND

• 60% of both parotid glands receive >30

Gy

• Dose spinal cord >50 Gy

• Volumes and doses to non-involved

normal tissues must not be excessive

TABLE 2

Study [ref.] Type of QA Number of casesevaluated n (%)

Minordeviations n (%)

Majordeviations n (%)

Technical issueswith QA review n (%)

Impact on clinical outcome

p value

HD 4 [5]

EORTC 20884 [2]

RTOG 0411 [4]

RTOG 9704 [1]

RTOG 0022 [8]

TROG 0202 [15]

R

R

R

R

R

P&R††

368 (98.0)

135 (88.8)

NS

416 (92.2)

67 (97.0)

687 (80.5)‡‡

–

–

–

–

47 (89.0)

–

141 (37.5)*

63 (46.7)

13 (13.4)

200 (48.0)**

6 (11.0)

97 (11.8)

8 (2.1)

46 (30.3)

NS

14/35 (40.0)†

14/67 (21.0)

33/820 (4.0)

7-year RFS with D: 72%

vs

7-year RFS without D: 84%

5-year RFS with D: 90%

vs

5-year RFS without D:84%

Grade GI ≥ 3 toxicity with D: 45%‡

vs

Grade GI ≥ 3 toxicity without D: 18%‡

mOS with D: 1.46 yo

vs

mOS without D: 1.74 yo

LRF with major D: 50%

vs

LRF with no major D: 6%

OS with major D: 70%

vs

OS without major D: 50%

0.004

0.31

0.05

0.008

0.04

<0.001

Abbreviations: R, retrospective; P, prospective; LRF, local-regional failures; D, deviations; mOS, median overall survival; RFS, relapse-free survival; GI, gastro-intestinal; NS, not specified.* Deviations were scored as adherence per protocol or less than per protocol (see main text for details).**Deviations were scored as adherence to protocol-defined volumes, dosimetry, treatment time and technical delivery characteristics (see main text fordetails).† Denominator is influenced by the number of patients with negative clinical outcome and/or the absence of delivered RT (see main text for details).†† QA of the TROG study was performed with a primary (interventional) prospective review and secondary review. Figures provided in the table are from thesecond retrospective review.‡ Observed toxicity during chemoradiotherapy.‡‡ Number of evaluated cases in the interventional prospective QA programme.

Table 1: Dosimetric definitions of major deviations for QART performed in prospective trials. © Elsevier, ‘QA makes a clinical trial stronger:evidence-based medicine in radiation therapy’, Damien C. Weber, Milan Tomsej, Christos Melidis and Coen W. Hurkman; Radiother Oncol 2012;105: 4–8

Table 2: Results of QART assessment with patients outcome in prospective clinical trials. © Elsevier, ‘QA makes a clinical trial stronger: evidence-based medicine in radiation therapy’, Damien C. Weber, Milan Tomsej, Christos Melidis and Coen W. Hurkman; Radiother Oncol 2012; 105: 4–8

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his year marks the 50th anniversary of theestablishment of the clinical bioengineeringservice in Edinburgh and provides anopportunity to review how bioengineering has

developed locally. The service officially began on 4thMay 1963 and half a century later, what began in asmall basement with a narrow remit for a singlediagnostic group has blossomed to offer services anddevices its founders would never have thought possible.

The purpose of the service as stated in its AnnualReport for 1986 still holds true today:

To respond to the problems of patients where adequatesolutions are not available within the existing routine clinicalservices. This may relate to the lack of particular knowledgeabout their condition and its management or the lack of asuitable device to alleviate their disability… The ultimateobjective of all our activities is the improvement of clinicalservices and our service to the disabled.

The scope of existing routine clinical services hascertainly widened in terms of equipment provision as

T


CLINICAL BIOENGINEERING FEATURE

devices that at one time would have been cutting-edgeand custom-made are now readily availablecommercially. The goalposts may, therefore, haveshifted but the role of bioengineering at the forefront ofproviding innovative solutions to complex problemsfor people with disabilities remains.

This article aims to give an overview of thedevelopment and work of the Edinburgh service. It isnot possible to cover or even mention all aspects soinstead, a few of the more noteworthy areas of workhave been selected for detailed coverage. The timeline(figure 1) gives an overview of key events andmilestones.

Origins and early years: 1963 to 1977

In 1963 funding was provided by the Scottish Home &Health Department to set up a small workshop in abasement in George Square, in close proximity to theRoyal Infirmary of Edinburgh and the University ofEdinburgh. The Powered Prosthetics Unit, as it was

Michael Dolan and David Gow (NHS Lothian) celebrate 50 years of the

clinical bioengineering service in Edinburgh and report on its milestones

Half a century of clinicalbioengineering in Edinburgh

‰

Clinicalbioengineeringhas come a longway in 50 yearsand the service inEdinburgh hasmade somepioneeringdevelopments

▼



In the early 1980s the centre established close researchlinks with the Department of Orthopaedic Surgery at theUniversity of Edinburgh in the area of fracture fixationand healing. Later that decade this collaboration saw thesuccessful development of a new cannulated tube saw forepiphysiodesis that was used by local surgeons andmanufactured by the centre until the early 2000s.

In June 1984, Thomas Dick was appointed as the thirddirector. One of the effects of the various research anddevelopment programmes and ad hoc patient serviceswas that the centre was at this time beginning toaccumulate a significant number of patients with a broadrange of unusual or difficult physical problems who beganto look to the centre for their ongoing care. As a result ofthis shift in emphasis, in 1987 the decision was made toemphasise the centre’s patient service activities byformalising patient referral procedures and by continuingto develop working relationships with referral sources.Research areas during this period included functionalelectrical stimulation and back topography, as well as aclinical trial of incontinence garments.

In 1988, oversight of the centre was transferred toLothian Health Board. This was one of the consequencesof the Scottish Home and Health Department’s review ofProfessor Ian McColl’s 1986 UK-wide report on artificiallimb and appliance centres. The report also provided auseful lever for research funding to, for example, help thecentre to experiment with silicone polymers to improvethe strength and durability of cosmetic covers for artificialhands. An umbrella organisation, called RehabilitationEngineering Service Lothian Area (RESLA) includingBioengineering, Prosthetics and Mobility, was formed andThomas Dick was appointed its first director with Dr BarryMeadows as Director of Bioengineering. To mark the 25thanniversary of the centre an open day and symposiumwas held reuniting former staff and patients alike.

originally known, was headed up by Dr (laterProfessor) David Simpson. It was charged with designingand providing upper limb prostheses for children bornwith limb abnormalities as a result of the drugthalidomide. Initially, referrals were received fromScotland, Northern Ireland and Eire. This was aparticularly difficult beginning due to the prevailingemotive atmosphere of politics and intense media interest.Within the first year, the unit employed four techniciansand a deputy director, but due to a growing workload andthe need for ongoing research and development it wassoon necessary to employ more staff.

In 1965, the unit moved 3.5 miles south to largerpremises on the Princess Margaret Rose (PMR)Orthopaedic Hospital site. From a clinical perspective thiswas the ideal location as it was the principal regionalhospital for the treatment of children with ‘disablingmusculoskeletal disorders’. To support the work, a SelfCare Unit was set up in 1966 to provide residentialaccommodation (consisting of three bedrooms, a dayroom, a sitting room and a kitchen) for ‘children withsevere limb deficiencies and their mothers’.

In 1967, the unit was renamed the Orthopaedic Bio-Engineering Unit and the Medical Research Council andthe Scottish Home & Health Department agreed toprovide and equip a new building. This was subsequentlyopened in 1969 as the Bio-Engineering Centre (the hyphenwas mysteriously dropped around 1986). The 325 m2

building contained a mechanical workshop, a plasticslaboratory and an electronics laboratory as well as clinicrooms and office and storage space. Staffing levelssubsequently peaked at around 25 and the focus of itswork began to expand to include aids for daily living(such as an IBM electronic typewriter adapted to operatewith a switch activated by a shoulder shrug in 1970) andspecial hospital beds and other large equipment.

The early pioneering work of David Simpson and theunit was recognised by many awards over the years. In1970 he was awarded the prestigious SG Brown Medal ofthe Royal Society and appointed Personal Chair ofOrthopaedic Bio-Engineering in 1972 by the University ofEdinburgh. Professor Simpson was also the President ofthe Biological Engineering Society (now subsumed in TheInstitute of Physics and Engineering in Medicine) between1972 and 1975. In 1977, Professor Simpson resigned as thedirector to take up a post at the University of Edinburgh.

Middle and later years: 1978 to 1999

In 1978 a new director, Dr Hamish Law, was appointed.The work of the centre continued and funding wasobtained for a number of projects, notably as one of thecentres for the UK trial of the Swedish System Teknikhand prosthesis for young children.

FIGURE 1.

[TOP RIGHT]

Major events andmilestones: atimeline ofclinicalbioengineeringin Edinburgh

▼

1963 1965

1967

1969

1974 1978

1984

1986 1988 1989

1993

1995

1997 1998 1999

2002 2003

2006

2008 2013

4th May 1963 - Powered Prosthetics Unit opened with

David Simpson as Director Moved to PMR Orthopaedic Hospital

New purpose-build Bio-Engineering Centre opened

Renamed Orthopaedic Bio-Engineering Unit

Physical Aids for the Disabled section formed

25th Anniversary event and RESLA formed

First gait analysis equipment installed

New Director Thomas Dick

New Director Hamish Law

New Director Barry Meadows

Clinic and office extension opened

New Director David Gow

Anderson Gait Laboratory opened

New purpose-build SMART Centre opened

Temporary move to Eastern General Hospital

Enabling Technology for Children launched

Touch EMAS spin-out company established

50th anniversary

Royal Academy of Engineering MacRobert

Award for i-Limb hand

David Simpson Library opened

TouchBionics formed

World’s 1st electrically powered shoulder fitted

‰

The early pioneeringwork of David Simpson and theunit was recognised by many

awards over the years“

“



In 1989 new office and clinic facilities and anoutpatients department for RESLA were opened in anextension on the end of the listed, modernist ClinicalResearch Unit. Excellent though the facilities were theyhad one major drawback; the new build was at theentrance of the hospital, but the bioengineeringworkshop remained in the original centre at the top of asteep hill. Any alterations to equipment or a requirementfor items from the store during a clinic appointmentnecessitated a round trip of nearly half a mile, adding atleast 10 minutes to the length of an appointment.

In 1991, Dr Barry Meadows was appointed Director ofRESLA. In 1993, David Gow was appointed the Directorof RES (the Lothian Area remit being dropped as aconsequence of the formation of NHS Trusts) and IanLoudon as the Head of Bioengineering Services.

On 27th October 1997, the new David Simpson Librarywas formally opened with a series of invited talksheadlined with a presentation from Professor DudleyChildress on ‘What the past tells about the future of limbprosthetics development’, in recognition of ProfessorSimpson’s seminal work on the control of upper limbprostheses.

Modern times: 2000 to date

The turn of the century marked a shift to a moreprofessionally accountable service. Since October 2000,clinical scientists have been required to be registered withwhat was then the Council for ProfessionsSupplementary to Medicine and is now the Health andCare Professions Council (HCPC). Of the six permanentbioengineers currently employed, four were‘grandfathered’ onto the original register (via IPEM’svoluntary register), one obtained registration throughRoute 2 and one is currently working towardsregistration via Route 2.

FIGURE 2.

[TOP]

The currentSMART Centre

▼

FIGURE 3.

[BOTTOM]

The currentEdinburgh teamof bioengineers.Back row (left toright): SusanHillman, ColinGeggie, GrahamHenderson andMichael Dolan.Front row: DavidGow, JenniferWalsh andJamesHollington

▼

With the opening of the New Royal Infirmary inEdinburgh, the PMR Orthopaedic Hospital closed toinpatients in January 2002. Bioengineering (along withProsthetics), however, remained on an increasinglydesolate site until May that year. The services moved totemporary accommodation at the Eastern GeneralHospital where it remained for over 5 years. The EasternGeneral Hospital was also in the process of being closedand, once again, the service was left as the only oneoperating from the site. The difficulties of operating fromthis site, in terms of its location and the temporary adhoc nature of the facilities, made the provision of aregional clinical service additionally challenging.

In December 2006, the Bioengineering and ProstheticsServices moved to their current location in the purpose-built Southeast Mobility & Rehabilitation Technology(SMART) Centre at the Astley Ainslie Hospital (figure 2).The following January they were joined by theWheelchair Service, Disabled Living Centre and DrivingAssessment Service. The 4,000 m2 building was officiallyopened on 26th February 2007 by the Deputy HealthMinister Lewis Macdonald. Although Bioengineeringhas had a somewhat nomadic existence over the years, ithas remained within a 3.5 mile radius of its originallocation.

The Orthotics service moved in to the SMART Centrein July 2011 to join with the existing services. Togetherthese now constitute the SMART Services. It covers theLothian, Fife and the Borders Health Board areas withDriving Assessment offering a national service.

At present there are six full-time, permanentbioengineers, or clinical scientists, and one Route 1 (PartII) trainee employed at the SMART Centre (figure 3).David Gow is currently the Head of SMART Services.Clinically, bioengineers lead the Seating, ElectronicAssistive Technology and Special Needs Design servicesand provide scientific support and expertise to theAnderson Gait Laboratory, the adult and children’swheelchair services, and the prosthetic and orthoticsservices. The workshop consists of six rehabilitationengineering technicians (clinical technologists), four ofwhom have been with the service for over 25 years. Theservices provide assessment, provision, clinical follow-up, ongoing equipment repair, maintenance andadaptation as required.

Upper limb prosthetics

The early years of the centre were devoted to theprovision of upper limb prosthetics (figures 4, 5 and 6).Initially it served a population of around 60 children,many of whom were followed from birth into youngadulthood. The first prosthesis with ‘extendedphysiological proprioception’ (EPP) was fitted to a child

A requirement for items fromthe store during an appointment

necessitated a round trip of nearlyhalf a mile“

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‰


Physical aids for the disabled

The 1974 a new internal section was set up – the MedicalResearch Council Unit for Physical Aids for the Disabled –to protect the powered prosthetic limb programme frombeing overwhelmed by other work and also to address theobvious and growing local demand for clinical-baseddesign and custom manufacture. An early example, from1964, was a feeding aid made for a child witharthogryphosis multiplex congenita (resulting in severelylimited upper limb movement). Gas power was used toraise a spoon, fork or cup and two levers were used torotate the plate and manoeuvre the implement in thehorizontal plane to the mouth (figure 8). NHS funding wassoon secured with a remit of ‘the design and production ofspecial aids for the handicapped, from beds and seat towheelchair’.

The requirement for special wheelchair seating grewsteadily and to such an extent that it required its owndedicated service. Over the years the section evolved andchanged, to become the ‘Specialised Aids for the Disabled’with two main functions of bespoke clinical provision forindividual patients and the long-term development of aidsthat would benefit large groups and that may eventuallybe manufactured commercially.

By 2000, the renamed ‘The Special Needs DesignService’ was receiving around 150 referrals annually thatresulted in the provision of a device by a full-time clinicalbioengineer supported by a full-time technician. Sincethen, with the increasing availability of commercialassistive devices the service has reduced in size (to around50 per year) but remains an important source of bespokesolutions for those with complex needs.

Over the years, the nature of the work has been diverseto say the least, from a cot rocking device, reinforcingwalking frames, providing night positioning equipment,an adjustable hip spica plaster casting frame, a glowplugcigarette lighter (figure 9), adaptations to allowparticipation in sports and other leisure activities tocustomising feeding aids and providing a interface to

in 1964. It had three movements; elbow flexion,pronation/supination and prehension. This wasdeveloped further with the addition of shoulderelevation and circumduction/humeral rotation. Thearms were gas powered as opposed to electricallypowered because electrical components, such as batteriesand motors, were too heavy for practical use at that time.Research and development continued alongside theclinical service, and included the development of acomplete adult arm prosthesis with endoskeletonconstruction and the functioning PMR hand with acosmetic glove. The development of a child’s handprosthesis and partial hand prostheses followed.

In 1979/1980, the centre, along with the localprosthetists, were involved in the clinical trial of theSwedish System Teknik hand prosthesis for youngchildren that went on to become routinely used. By themid 1980s a database on an Apple microcomputer wasbeing used to store patient records. By the time the centrecelebrated its 25th anniversary the original patient groupwere all adults and this aspect of the centre’s work hadwaned. Research nevertheless continued in the area ofupper limb prosthetics, though now electricallypowered, and cosmetic gloves.

On 26th August 1998, after 11 years of research anddevelopment (with funding from the Scottish ChiefScientist’s Office), the first complete powered electricalarm prosthesis (know as the Edinburgh Modular ArmSystem [EMAS], figure 7) was fitted at the centre andwitnessed by seven television crews and over 30journalists and photographers from all over the world.The user continued to use the arm for 18 months andworked with the team to develop and improve itsfunctionality, and several other arms were manufacturedand fitted to other users. The core component of the armwas a patented powered lever system which was used in2006/2007 in the so-called ‘International Arm Fittings’ inChicago, including the world’s first female powered armwearer.

FIGURE 7.

[TOP RIGHT]

The EdinburghModular ArmSystem (c1995).Electric-poweredarm movementswere based onthe gas-poweredarm work andstructure

▼

‰FIGURE 4.

[TOP LEFT]

Early mid to late1960s gas-powered upperlimb prosthesis

▼

FIGURE 5.

[BOTTOM RIGHT]

Radiograph of aCO2 cylinderused in the upperlimb prostheses.A silencerensured that thesound of theexhaust wasinaudible in mostcircumstances

▼

FIGURE 6.

[BOTTOM LEFT]

Passive arm(series II) withgas-poweredcommercial hand(c1971). CO2 gasbottle is locatedin the upper arm(regulator notshown)

▼


FIGURE 8.

[LEFT]

Gas-poweredfeeding aidoperated bymicrovalve andlevers (1964)shown withspoon. Thedevice wasclamped to atable, as shown,or to awheelchair tray

▼

FIGURE 9.

[BOTTOM RIGHT]

The glowplugcigarettesmoking aid(c1997) designfor individualswith motorneurone diseaseor Huntington’schorea whowished tocontinue tosmokeindependently

▼

FIGURE 10.

[TOP RIGHT]

Epiphysiodesistube saw (c1998).A: Steinmannpin; B:centralisingcylinder; C:hollow tube saw;D: threaded endpiece; E: T-handled extruder

▼

microcomputers with around 15 patients trialling fivedifferent input devices.

In the late 1980s the service, in collaboration with theUniversity of Edinburgh’s Communication, Access,Literacy and Learning (CALL) Centre, developed andtrialled the ‘smart wheelchair’ with sensors mounted inthe front and rear bumpers. It was designed to givechildren who could not control a conventional poweredwheelchair the educational experience of independentmobility. This went on to be further developed by theCALL Centre and was subsequently commercialised andis still available from Smile Rehab Limited (Newbury).

The advent of smaller ventilators and theestablishment of an Edinburgh-based home ventilationservice in the late 1990s led to the service becominginvolved with powering ventilators from wheelchairbatteries and manufacturing mounts to carry theventilators. Newer, more energy-efficient ventilators andbetter battery technology means that it is no longernecessary to provide power from the wheelchair and thelast one was recently taken out of service.

During the late 1980s, the Control Interface Servicewas formally set up to primarily provide special controls,e.g. a single switch for powered wheelchairs, as well asindividually adapted mounts for remote joysticks,controllers, switches and communication aids (figure 12).

Environmental control systems enable very severelydisabled people to control electrical equipment such asalarms, pagers, telephones, intercoms and homeentertainment equipment. Up until 1997, environmentalcontrol systems were funded separately and installed andmaintained by commercial contractors. In 1999,Bioengineering took on the installation and maintenanceof environmental control systems and since that date allnew Lothian installations have been fully fitted andmaintained by the in-house team. The resulting savingshave allowed many more systems to be provided andcurrently there are 96 environmental control installationsin Lothian. Where appropriate the service also integrates

allow an upper limb prosthesis user to carry a London2012 Olympic torch.

Orthopaedic biomechanics

During the 1980s the centre undertook a number ofcollaborative developments with the Department ofOrthopaedic Surgery led by Edward Draper. One project,an investigation into the effect of later fracture shift, led tothe design and construction of a bone torsion testingmachine. The output from the strain gauge amplifier wassampled using the analogue input of a BBC model Bmicrocomputer which was subsequently used to analysethe resulting data. Another project was to design anexternal fracture fixation system that would be easier tofit in the operating theatre and allow for bothcompression and distraction. Work was also carried outon the mathematical modelling of fracture fixators, themechanical properties of tendon sutures and thefeasibility of using foil strain gauges on fracture fixators.

During the mid 1980s a surgical tube saw wasdesigned in cooperation with a local orthopaedic surgeonto improve the technique of epiphysiodesis – the methodused to correct moderate, from 2 cm to 5 cm,discrepancies in leg length during childhood. The sawoffered significant advantages over other methods: ashorter and less traumatic surgical procedure, a reducedrecovery period, no need to immobilised the leg inplaster, and overall superior cosmetic results. Therelatively simple equipment (figure 10) was developedover a 10-year period and continued in use for around afurther 10 years.

Electronic assistive technology

The need for suitable control systems for electricallypowered prostheses (figure 11) and wheelchairs hasmeant that electronic assistive technology has been at theheart of bioengineering in Edinburgh for many years. Inthe mid 1980s, research funding was obtained to developinterfaces for tetraplegic patients to access


recently, bioengineers have once again becomeincreasingly involved in research and development in thisarea with a particular focus on clinical and ISO technicalstandards and models of service provision.

Clinical gait analysis

The first gait analysis system (consisting of three infra-redcameras, a force platform and an eight-channel EMG) wasinstalled in 1986 for research and teaching purposes in thehospital’s physiotherapy gym. Subsequently, when thelaboratory was relocated into its own space (within themain hospital building), the laboratory was named theAnderson Gait Laboratory after the James and GraceAnderson Trust in recognition of their support andgenerous funding of research. It was formally opened bythe Scottish rugby international Gavin Hastings on 8thNovember 1995. The clinical gait analysis service, likemany other aspects of the centre’s current work, started asresearch and development and gradually progressed intoa routine clinical service with recurrent NHS fundingsecured in 1996 (figure 14). The laboratory has a highlysuccessful research record with a particular focus on theclinical relevance of gait analysis in children with cerebralpalsy, but has also published widely on thecharacterisation of normal gait in children and thedevelopment of the Edinburgh Visual Gait Score. Indeed,gait analysis accounts for around 25 of the 85 or so peer-reviewed journal articles that have been published on thecentre’s work.

Today, the gait analysis system consists of six high-definition infra-red cameras, two force platforms and a 16-channel wireless EMG and is staffed by a highlyexperienced, multi-disciplinary team with particularexpertise in cerebral palsy.

Commercialisation

The benefit to the wider population of people withdisabilities of commercialising devices developed by theservice appears to have been recognised very early in the

environmental controls with wheelchair controls toenable both to be operated via the same switch or joystick.

Wheelchairs and seating

In Edinburgh, bioengineers have not been directlyresponsible for the provision of wheelchairs but over anumber of years have become increasingly involved withthe provision of special seating, i.e. postural support, inwheelchairs, and with adaptations to the somewhatlimited range of standard ‘ministry’ wheelchairs availableto the NHS up to the turn of the century. In the early daysthis was very much on an ad hoc basis with therapists, orother clinicians, requesting help with particularlychallenging cases; an example was the provision of anadjustable tilting tray for mounting a Bliss communicationboard on a wheelchair that was requested by a speechtherapist in 1980.

During the mid 1980s research funding was obtained todevelop special seating and also arm crank wheelchairpropulsion. Over time seating developed into a clinicalservice for which an increasing number of people havecome to rely on. By 2004 the number of adults usingseating provided by the service was around 600, anincrease of 50 per cent in 5 years. The equipment providedhas gradually moved from being mostly manufactured in-house (figure 13) to being hybrids of commercialequipment with bespoke modifications as required. In2011, a foam carver was purchased with a view toreducing the service’s reliance on external contractors forcustom contoured seats.

In 1999, a dedicated bioengineer-led children’swheelchair and seating service, called EnablingTechnology for Children (ETC), was set up under theleadership of Ian Loudon. A paediatric physiotherapistwas employed to work with the lead bioengineer, as wellas an experienced senior technician. The service is nowtherapy-led with bioengineer support. The seating serviceconcentrated on adult cases and continues as abioengineer-led service with therapist support. More

‰FIGURE 11.

[TOP LEFT]

Part of the in-house designedandmanufacturedcontrol circuitryfor theelectricallypowered armprosthesis(c1998)

▼FIGURE 12.

[BOTTOM LEFT]

An integratedwheelchaircontrol/communicationaid controlsystem withcentralcontroller visiblenear the cornerof the tray (1999)

▼

FIGURE 13.

[RIGHT]

An in-housemanufacturedseat insert withramped seatbase, shapedback, pelvicpadding andcurved headsupportmounted on atiltingwheelbase witha commercialhip belt (c1999)

▼


Summary

Over the past 50 years the Edinburgh service hasevolved and adapted to suit the demands of itsstakeholders and technological and societaldevelopments and challenges. Some areas of researchand development, such as the Simpson-EdinburghAirbed, have passed into the mainstream and would,quite rightly, no longer be considered to requirespecialist clinical bioengineering input.

Some areas have waxed and waned as demands ofreferrers and the priorities of research funders havechanged. All clinical services have become subject toincreasing scrutiny and regulation. The MedicalDevices Directive is paramount in this regard as allcustom-made devices must meet the essentialrequirements for patient safety. Bioengineersthemselves have evolved into HCPC registered clinicalscientists with all the requirements that come withmodern health professional regulation.

Although this article is specifically about theEdinburgh service, little can be achieved in science andtechnology without collaboration and in this respect,Edinburgh is no exception. Indeed, the service wasestablished following a visit to Professor ErnstMarquardt in Heidelberg, Germany, and manysignificant areas of work have been carried out with thehelp of and in collaboration with other services. InScotland these include the Dundee-based TaysideOrthopaedic and Rehabilitation Technology Centre (e.g.gait analysis and wheelchair seating), the University ofStrathclyde’s Bioengineering Unit (which is alsocelebrating its 50th anniversary) and, of course, variousdepartments of the Edinburgh-based universities.

It would, perhaps, be foolish to predict how clinicalbioengineering in Edinburgh will develop and changeover the next half a century, beyond saying that theservice will not go far wrong if it remains true to itspioneering spirit of innovation and the application oftechnology for the clinical benefit of its patients. n

centre’s history. Over the years numerous devices havebeen commercialised with varying degrees of success.These range from the original PMR hand to the Rennie-Edinburgh wheelchair harness.

The mid to late 1970s saw the development of theSimpson-Edinburgh Low Pressure Airbed (figure 15). Itwas designed to be economic and prevent pressuresores by maximising the surface area supporting thebody and reducing pressure, and the basically simpledevice proved to be extremely effective. Followinginitial research and development, a successful trial of 64airbeds led to the commercial production by RobertKellie and Sons Ltd (Dundee). Several models wereproduced and it continued in use well into the 1990s.

During the early 1980s it was recognised that therewere no suitable mobility devices for children thatcould provide both postural support andindependence. Following initial development and trialsin local schools for the disabled, the design waschanged from a quadrilateral to a triangularconfiguration, into what became known as the ‘arrowwalker’ (figure 16). In 1993, this was commercialised byTheraplay Ltd (Glasgow) and there are now severalvariations on the market today. An adult version wassubsequently developed and successfully field trialled,though due to its size it was found not to be suitable foruse in a domestic environment.

In 2002, TouchEMAS Ltd was the first spin-outcompany to be launched via Scottish HealthInnovations from the NHS in Scotland. It wassubsequently renamed TouchBionics and was awarded‘Most Promising New Life Sciences Company’ inScotland in 2005. It is now based in Livingston andcontinues to develop and launch new products, and hasfitted hundreds of upper limb prostheses across theglobe. In 2008, David Gow and TouchBionics wereawarded the prestigious Royal Academy ofEngineering’s MacRobert Award for the developmentof the i-LIMB hand.

FIGURE 14.

[BOTTOM RIGHT]

Anderson GaitLaboratory whenbased in a formerward during thecentre’srelocation to theEastern GeneralHospital (2002)

▼

FIGURE 15.

[TOP RIGHT]

The Simpson-Edinburgh LowPressure Airbeddevelopmentversion. Twostandardcampingmattresses wereused to preventthe patientbottoming outand coming intocontact with thewooden base

▼

FIGURE 16.

[LEFT]

Arrow walkerwith saddle seat,three frontcastors and onerear castor(c1994). The userholds the handlebar (top right)and rests elbowson the supportpad

▼


TREATMENT INTERRUPTION FEATURE

How have we been doing in the UK?

In 2005, 63 per cent of the 631 patients in a Royal Collegeof Radiologists (RCR) audit registered by 48 of the 57 UKcentres had one or more treatment interruptions,compared to 60 per cent in 2000. However, in 2005 88 percent of patients with interruptions completed treatmentwithin 1 day of target and 95 per cent within 2 dayscompared to 69 per cent within 2 days in 2000. So thereseems to be a decreasing need for corrections using thesecond method, requiring individual radiobiologicalcalculations for each such patient. Different countries mayhave different records in this respect.

A second type of strategy retains overall time and alsoone fraction per day, but the size of the dose per fractionis increased by a carefully calculated amount. Forexample, this may be done for the same number of ‘post-gap’ days as gap days (Method 2). However, with thismethod calculated ‘iso-effect doses’ cannot ever beexactly the same for late reactions as they are for ‘tumourcontrol’, so there is the well-known compromise to bemade – a little less tumour control or a little more latecomplications (Methods 2a and 2b)? Which disadvantagewill you choose? It has to be one or the otherdisadvantage. We shall explain how to estimate theirrelative size here.1, 3

Methods to compensate for missed days

The methods are discussed more thoroughly in reference2, all using the same LQ arithmetic, which is no morethan introductory algebra, but it depends how rusty youare! Always get your LQ calculation checked by anotherperson!

The tissue-dependent radiobiological ratio

alpha/beta

α is the coefficient proportional to the ‘one-hitunrepairable’ radiation damage (e.g. breaking the double

here is much evidence on the detrimentaleffect on tumour control of missed treatmentdays during radiotherapy. ‘The mean loss of 1.6per cent per day of prolongation in local controlin head and neck cancer (range 0.4–2.5 per cent)

has been well recorded…‘1 This is the first publicationthat raised this problem quantitatively. Another way ofexpressing the same loss rate is as loss of ‘treatment doseper day’, which is 0.6 Gy (in terms of 2 Gy fractions =EQD), also called the K factor.2 It is lower for slower-growing tumours. Even in the slowest tumours (e.g.prostate) it can reach about half that rate (K = 0.25 Gy/d)(Howard Thames, but only after 50 days of radiotherapy,his cut-point). Cervical and uterine cancer can repopulateat half the head and neck rate (K = 0.4 Gy/d; 0.2–0.7),1

probably starting from an earlier cut-time than 50 days.The most rapidly repopulating tumours include head andneck, lung and those in the gastro-intestinal tract.1, 2

Protocols since 1996

Since 1996 most radiotherapy departments worldwidehave developed protocols for avoiding interruptions intreatments, and for corrections if they do occur. The RoyalCollege of Radiology is very clear about this: 2 ‘Thereshould be a designated person in each department tomonitor the frequency of interruptions arising intreatments, determine their cause (table 1) and developprocedures to prevent their occurrence. It is important tostress to all patients and to staff that every effort shouldbe made to avoid interruptions in treatments once started.If this does occur, compensatory treatment is required.’

Overall time and fraction size can be maintained bytreating on weekend days (the preferred way, Method 1a)or by using two fractions a day to ‘catch up’ (Method 1b).The latter might incur a small loss of tolerance regardinglate reactions, calculated later, when intervals of 6–8hours and 18 hours are used rather than 24 hours.

T

Jack Fowler (University of Wisconsin, Madison, USA) describes methods to correct for

missed treatment days during radiotherapy, calculating advantages and disadvantages

To correct for interruptions inradiotherapy treatments

TABLE 1

Department-related Patient-related

Planned Unplanned Planned Unplanned

Public holidaysMachine service time

Machine breakdown Staff shortage

Unwillingness of patientFamily holiday

Treatment toxicityOther illness

TABLE 1.

Causes of treatment interruptions

s


strands of DNA) that kills biological cells, and β is thecoefficient proportional to damage caused by ‘two ormore hits’ (ionisations). If the latter ionisations aredelivered at long times or distances apart (as in low dosesper fraction or low dose rates), repair can occur in thetime between them so the number of cells killed by agiven dose of ionising radiation will depend on the timeof delivery of dose and this ratio of alpha to beta,designated the α/β ratio. Tumour cells often (but notalways) have high α/β ratios, but late-responding normaltissues always have low ratios of α/β. This difference is ofvital importance in different tissues, and the choice ofdose-per-fraction in radiotherapy will often dependmainly on this α/β ratio.

The basic form of LQ is log cell kill = αd + βd2, = alinear plus the dose-squared term, as described furtherbelow and in references 3 and 4.

To compensate for missed dose fractions

Overall time and fraction size can be maintained bytreating patients on weekend days (the preferred way,Method 1a), although with unsocial hours and at extracost, or by using two fractions a day to ‘catch up’(Method 1b). The latter might incur a small loss oftolerance regarding late reactions when intervals of 6–8hours are used rather than 24 hours, and there may belogistical scheduling difficulties with larger numbers ofpatients in some centres.

The object is to maintain prescribed overall time andtotal biological dose as nearly as possible. I will give youmy personal way of using LQ to calculate iso-effectivedoses. First of all, find out how many days are still tocome in the present treatment from the start of theinterruption, then calculate relative effectiveness3 (RE = (1+ d/[α/β])) of the fraction size d being used, using the α/β

ratio of the tissue of concern. Then use the seven steps toLQ heaven – meaning you won’t be confused by LQ everagain – to calculate the intended BED (biologicallyeffective dose). The gap in BED to be compensated willthen be obvious.

Linear quadratic calculations to keep cell kill

constant

Seven steps to LQ heaven

Let E be the number of logs(exponential) of cells sterilisedby n equal fractions of d Gy each:

E = n (αd + βd2) (1)

where α is proportional to the one-hit non-repairable cellkill and β is for two or more ionisations (hits) to kill a cell,with repair or recovery occurring if there is time betweenthe hits and if the hits are a long distance apart, as at lowdoses per fraction.

If you remember this equation, all else is easy.

E = nd (α + βd) (2)

simply takes the d outside the bracket. Now we know thatα/β = 3 or 10 Gy for late or early responding tissues, sowe want to obtain this ratio in the formula. We coulddivide either by α or β, but dividing by α is better because

Treatmentinterruptionscan occur for anumber ofreasons

sit avoids dimensions of beta (in dose squared), whichcould be awkward.

E/α = nd (1 + βd/α) (3)

Now we want α/β ‘THAT WAY UP’:

E/α = nd (1 + d/(α/β)) (4)

and changing it to the bottom line does that. See? This gives biologically effective dose,3 and NOT

biologically equivalent dose! To change this to the familiar total dose in 2 Gy

fractions, just divide any BED by the RE for d = 2 Gyusing the α/β ratio of 10 Gy for tumours, but α/β = 3 Gyfor normal tissue complications (NTCP). If the relevantnormal tissue is spine or brain, use α/β = 2 Gy.

Now we have obtained equation 4 for BED(biololgically effective dose) in special ‘biological doseunits’, which we can call ‘Gy10’ if α/β was 10 fortumours, or ‘Gy3’ if the normal tissues at risk are late-responding, as they often are. This subscript to give α/β

has become usual, but the terms could very well be calledBarendsens (Bd), to avoid the confusion with physical Gyor the acroym BED mentioned above after equation 4. Yousee, the α/β is all-important and defines the tissue we arelooking at.

This is ‘halfway to LQ heaven’, being the definition ofBED as equation 4. You can do a great deal with nofurther complications, especially to check out theradiation damage you are doing to tumours and, with adifferent α/β ratio but the same dose, the late damage tonormal tissues. (The next three steps allow forproliferation, and this gets much more complicated,requiring three more factors, so I’ll keep it short. Justhang on to equation 4 – only read the next three steps ifyou’re really interested.)

‘ YOUR LETTERSScope welcomesyour feedback!


‰



RE is one of the most useful concepts of LQ algebra.

BED = E / α = n × d × ( 1 + d/[α/β]) (4)biologically real relative effective physical effectiveness = (1 + d/[α/β])dose dose

There are three additional steps, allowing forrepopulation in continuing irradiation. You will not needthese three steps unless the overall time changes.

The number of cells in tumour doubles in Tp days so:

Rate = (loge 2)/Tp (5a)

Repopulation starts at time Tk days, continues to theend of treatment at T days. So the time available forrepopulation is:

T – Tk days (5b)

Total E = nd (a + bd) – (T – Tk) (loge 2)/Tp (6)

but remember that BED = E/a.So

BED = nd (1+ d) – (T – Tk) 0.693 (7)α/β α Tp

Don’t forget to finally divide by α! That’s the end of our seven steps to LQ heaven. The

additional three factors that we have to know, or toguess, so as to estimate the whole BED at the end of aschedule, now include α, Tp and Tk as well as d and α/β,

which is all we need to compare two schedules.Remember that to get total dose EQD (in 2 Gy fractions),just divide any BED by the RE for 2 Gy fractions and therelevant α/β ratio.

How big is this problem for different tumours?

The only reliable way to obtain this information aboutany sort of tumour is to get data from a controlled clinicaltrial in which two different overall times were used fortwo groups of otherwise identical patients, i.e. only theones treated for longer overall times only by

randomisation. This is of course rarely done, so exactdata are still rare. However, the rates of tumourrepopulation are expected to be related to their measuredpotential doubling time (Tpot), which is the period indays required for the number of malignant cells todouble, in an untreated tumour that is not experiencingany cell loss.

Many types and locations of human tumours weremeasured by tritiated thymidine labeling and flowcytometry in the 1980s and 1990s (table 2).4 Even withinone type there will be a wide individual range.

Section 3 (page 14) of reference 2 gives suggestions forpriorities of patients by site of tumour, and a list of fast-repopulating tumour sites that should not be givenprolonged treatment even for compensation of aninterruption. Notable are the very slowly dividingtumours, prostate and brain, which are as slowlyproliferating (before any treatment of any kind is given)as late-responding normal tissues, and so invite the useof hypofractionation, as has happened in prostate cancer,followed, increasingly, by breast, and probably bladder,then possibly ovarian cancer. But we are now using thisTpot data in a speculative way, led still a little cautiouslyin the case of prostate cancer, which the world ofpractical radiotherapy is now following. The questionmarks in the column of α/β values in table 2 are openinvitations for useful research. (To find α/β ratiosrequires good data from different doses-per-fraction.) Itis useful if clinicians bear in mind those values of α/β

and the somewhat less relevant Tpots as possibleindicators of where the field might go next.

Examples of corrections for a 5-day

interruption (1 week of gap) before half-time

Let us look at a planned schedule of 30F × 2 Gy

in 6 weeks

n Method 1a: maintain overall time by using weekendtreatments – the preferred strategy. n Method 1b: two fractions a day of the usual size, onthe remaining days between the gap and the end oftreatment, at least 6 hours apart but 8 hours is better. Ifthe gap was longer than 3 days, the dose per fractionshould be slightly reduced by calculating for completerepair with bi-exponential T−1/2s, equally 0.3 and 4

‰

TABLE 2

Site of tumour Number of patients Tpot (days and range) Tumour α/β ratio

Head and neckBrain and spineUpper intestinal ColorectalBreast* Ovarian Malignant melanoma Haematological BladderRenal cell Prostate** with extra patients from Haustermans

71219318334515955241061927

4.5 [1.8–5.9]34.3 [5.4–63.2]5.8 [4.3–9.8]4.0 [3.3–4.5]14.0 [8.7–17]12.5 7.2 9.6 [2.3–18.1] 17.111.3 42 [17–100]

10 Hendry? Low 10 Withers? 10 4.7 Yarnold? <100.6 Bentzen?? <10? 21.5 Miralbel, Hendry

TABLE 2.

The types andlocations of thetumoursmeasured4

s



REFERENCES

1 Hendry JH, Bentzen SM, Dale RG et al. Amodelled comparison of the effects of usingdifferent ways to compensate for missedtreatment days in radiotherapy. Clin Oncol 1996;8: 297–307.

2 Board of Faculty of Clinical Oncology, RoyalCollege of Radiologists. The Timely Delivery ofRadical Radiotherapy: Standards and Guidelinesfor the Management of Unscheduled TreatmentInterruptions, 3rd edn. Ten–member WorkingParty, 2008.

3 Fowler JF. The linear-quadratic formula andprogress in fractionated radiotherapy. Reviewarticle. Brit J Radiol 1989; 62: 679–94.

4 Steel GG. Basic Clinical Radiobiology, 3rd edn.London: Arnold, 2002.

hours. Two fractions of 2 Gy a day require a total dosereduction of 9 per cent if continued for more than 3 days.n Method 2: maintain overall time with increased dose-per-fraction and one fraction a day. Instead of the usual15F × 2 Gy = 36 Gy10 to tumour and 50 Gy3 to lateNTCP we have only 10 treatment days available to givethese doses. Ten tumour doses of 2.81 Gy will solve thetumour problem, giving 36 Gy10 as required, to the fullBED. But these same doses will deliver more than theplanned 50 Gy3 to late NTCP, in fact 54.4 Gy3, makingthe late complications BED 104.4 Gy3, now 4 per centhigher than our prescribed 100 Gy3. This could lead to8–12 per cent more late complications than the usualproportion. Is that an acceptable risk? If not we have tocome down by ~2 per cent on the planned total dose totumour, which would be a 4 per cent reduction intumour control probability. Such compromises are usualif interruptions occur.

So it is important not to allow interruptions. n

‘ ABOUT THEAUTHOR

Jack FowlerDSc, PhD,FInstP, FIPEM,FRCR,FBIR,FAAPM,FACR,FACRO,FAstro.EmeritusProfessor ofHuman Oncologyand MedicalPhysics,University ofWisconsin,Madison, USA.Ex Gray Lab,Mount VernonHospital, UK.

Benjamin W. Infantolino1, 2 and John H. Challis2 used ultrasound,

rather than conventional imaging, to measure muscle volume in vivo

Estimating musclevolume using ultrasound

bstract

An important descriptor of musclearchitecture is muscle volume, particularlybecause the power a muscle can produce isdirectly proportional to its volume. The

tracking of muscle volume in vivo can be useful forexample for examining how muscle size changes duringchildhood, during disease processes and for the trackingof muscle changes due to rehabilitation exercises andtraining for sports. Muscle volume is typically estimatedusing an imaging method, such as magnetic resonanceimaging (MRI) or computed tomography (CT), to obtainviews of the muscle cross-sections. From these musclecross-sections, the area of each image is measured andfrom series of these cross-sections and the distancesbetween them the muscle volume can be estimated.

The purpose of these studies was to demonstrate thatmuscle volume can be estimated in vivo by usingultrasound, a cheaper, more portable and lesscontraindicated imaging method compared with MRI orCT. To evaluate ultrasound as a method to determinemuscle volume, vastus lateralis and first dorsalinterosseous muscles were imaged in cadavers. Then themuscles were dissected and their volumes measured

directly; the direct measures of volume and theirestimated volumes were compared.

The results demonstrated that ultrasound can beused to accurately estimate muscle volumes in vivo. Themuscle volumes used ranged from some of the smallestto the largest found in the human body, showing thegeneral utility of ultrasound for measuring musclevolume in vivo.

Introduction

The geometrical arrangement of muscle (called musclearchitecture) is important in dictating the function of amuscle. Measurement of muscle architecture in vivo isimportant for tracking: disease processes, the impact ofrehabilitation protocols, muscle changes with ageingand for the construction of subject-specific musclemodels. One aspect of muscle architecture, musclevolume, can be used to estimate the maximal power amuscle can produce.

Muscle power production is a crucial indicator ofperformance; for example, in the elderly the ability toproduce power is strongly related to the ability toperform activities of daily living.1 The measurement ofmuscle volume in vivo allows clinicians to track the

A

‘ AFFILIA-TIONS

1. Penn StateBerks, USA

2. BiomechanicsLaboratory,PennsylvaniaStateUniversity,USA

‰


MUSCLE VOLUME FEATURE

‰



progress of a muscle training programme or a disease,and allows researchers to gain better insight into thefunctions of muscles.

Muscle volume has been estimated using magneticresonance imaging (MRI),2 computed tomography(CT)3 or ultrasound.4 Irrespective of the imagingmodality, all muscle volume estimations areperformed using the Cavalieri principle.5 Previousstudies have used one imaging modality to assess theaccuracy of the another imaging modality.6 Thelimitation to this method of accuracy assessment isthat the error associated with one imaging method(e.g. muscle identification) is the same for the otherimaging modality, so under this paradigm no goldstandard exists. Scott et al.7 used MRI to estimate thevolume of 18 muscles in the lower leg of one cadaverand compared the estimated volumes with the musclevolumes measured using water displacement. Thelimitations of their study were that only one leg wasexamined, and that the muscles examined were someof the larger ones in the human body.

Drawbacks exist for both MRI and CT for theestimation of muscle volume in vivo. MRI iscontraindicated for patients or subjects with metalimplants and for individuals with claustrophobia. CTis a radiation-based imaging modality, so the repeatedmuscle volume measurements that would be requiredfor tracking muscle volume changes due, for example,to ageing are not feasible. Ultrasound does not havethe contraindications of MRI nor the radiationconcerns of CT. In addition, ultrasound equipment ismuch cheaper and portable than carrying out MRI andCT. The purpose of the following study was toexamine the accuracy of ultrasound in estimatingmuscle volume for the range of muscle sizes found inthe human body.

Methods

General methods

To estimate muscle volume using ultrasound theproximal and distal ends of the muscle are locatedusing ultrasound. This length of the muscle is dividedinto equally spaced (1 to 2 cm) intervals. If the muscleis too wide to be viewed with one ultrasound scan themuscle is divided using thin (22 gauge) wires. Thewires show up on the ultrasound image, ensuring nopart of the muscle would be missed or doublecounted, as shown in figure 1. Ultrasound images ofmuscle cross-sections (see figure 2) are saved to apersonal computer for further processing. Once theentire muscle is imaged, the cross-sectional area of themuscle in question in each image is measured usingthe freeware program Scion Image (now ImageJ,http://rsbweb.nih.gov/ij/). Successive cross-sectionalareas (CSAi) and the distance (hi) between them allowscomputation of total muscle volume (V) estimatedusing the Cavalieri principle:5

(1)

FIGURE 2.

[TOP RIGHT]

Ultrasoundimages ofmuscle cross-sections

▼FIGURE 1.

[TOP]

Wires showinghow the muscleis divided

▼

FIGURE 3.

[LEFT]

The vastuslateralis is alarge muscle inthe superficiallateral thigh

▼

FIGURE 4.

[MIDDLE

RIGHT]

The first dorsalinterosseousmuscle is asmall muscle inthe first web-space of thehand

▼

FIGURE 5.

[BOTTOM

RIGHT]

The system ofwires used tobreak up thevastus lateralis

▼Muscles analysed

Two different muscles were analysed: the vastuslateralis8 and the first dorsal interosseous.9 The vastuslateralis is a large muscle in the superficial lateralthigh, figure 3, and represents one of the largermuscles in the human body.10 The first dorsalinterosseous muscle is a small muscle in the first web-space of the hand, figure 4, and represents one of thesmaller muscles in the human body. The vastuslateralis muscles of four cadavers were imaged but inone case the vastus lateralis was fused to the nextmuscle deeper giving a total of seven musclesanalysed, and the first dorsal interosseous muscles of11 cadavers were imaged giving a total of 22 musclesanalysed. All cadavers were embalmed and allcadaveric research was performed followinginstitutional-approved ethical, safety and biohazardstandards.

Muscle scanning

Both muscles, the vastus lateralis and the first dorsalinterosseous, were scanned using a 7.5 MHz linearultrasound probe (SSD-1000, Aloka, Japan) in B-mode.To enhance muscle image quality a stand-off pad (2 cmthick and 9 cm in diameter) and a small amount ofultrasound gel were used. Both the stand-off pad andultrasound gel aid in the transmission of sound wavesbetween the probe and the body. The skin was markedwith a wax pencil in 2 cm (vastus lateralis) or 1 cm(first dorsal interosseous) increments from the distal tothe proximal end of the muscle. The vastus lateralis iswider than the ultrasound probe and so the system ofwires was used to break up the vastus lateralis (figure5) whilst the first dorsal interosseous was imaged inone ultrasound image.

Direct muscle volume measurement

Once the muscles were imaged, they were removedfrom the cadavers using blunt dissection. Immediatelyupon removal the mass of each muscle wasdetermined using an electronic balance. Muscles werethen placed in a self-sealing polyethylene bag andevacuated of air to prevent loss of fluid. Musclevolume was then determined directly. For the vastuslateralis muscle underwater weighing was used. Thefirst dorsal interosseous muscle was too small forunderwater weighing to be accurate so the waterdisplacement method was used instead. In both casesthe muscles remained in the bag to prevent fluidtransmission and the mass of each muscle wasmeasured after volume determination to confirm thatno fluid was lost or absorbed.

Operator reliability

For the vastus lateralis intra-operator reliability wasassessed. The volume of a muscle was estimated fromone set of muscle images by three operators. Inter- andintra-operator reliability was assessed for the firstdorsal interosseous. One operator estimated musclevolume from the same image set twice for all musclesand two operators estimated muscle volume using thesame image set for all muscles. ‰



Finally, since probe orientation with respect tothe normal can cause a change in the area of musclecross-section being imaged,11 one first dorsalinterosseous muscle was imaged with varying probeorientations. The estimated muscle volumes werecompared for the probe oriented perpendicular to themuscle surface and at 5 degrees off of the normalangle. Five degrees was chosen because anythinggreater than this is easily visually identified andwould be corrected by the operator before the imageis recorded.

Statistics

For the comparison between estimated and directmuscle volumes the graphical method of Bland andAltman was followed.12 In this method, the differencesbetween measures (directly measured and estimatedmuscle volume) are plotted against the mean of thetwo measures. The straight line fit to this dataindicates whether there was relative bias in the data(constant offset), and the line’s gradient indicateswhether there was proportional bias in the data. Tocompare inter- or intra-operator errors, intra-classcorrelations (ICC; 2.1) were computed.13 To assesswhether probe orientation had an influence onestimated muscle volumes a repeat measures ofvariance was computed.

Results

The Bland–Altman plots of two measures of musclevolume for both the vastus lateralis and first dorsalinterosseous muscles indicated that the measures fellwithin a 95 per cent confidence interval of agreementbetween the ultrasound measures and the directvolume measures (figures 6 and 7). These data alsodid not have a relative bias (p > 0.05) or aproportional bias (p > 0.05).

For the vastus lateralis the intra-class correlationwas high (ICC > 0.8) between three measurers. Forthe first dorsal interosseous the intra-classcorrelation was high (ICC > 0.8) between twomeasurers, while for this muscle the intra-classcorrelation was high (ICC > 0.8) for repeat measuresmade by the same measurer.

Probe orientation did not have a significant effecton estimates of the first dorsal interosseous musclevolumes (p > 0.05).

Discussion

The results of these studies indicate that the volumeof human muscles can be estimated both accuratelyand reliably using ultrasound. Inter- and intra-operator reliability was high, indicating that thevolume estimates are repeatable for the sameoperator and different operators. Probe orientationwas also found not to have an effect on musclevolume estimation. It is possible that probe anglesrelative to the muscle greater than 5 degrees couldproduce significant differences in muscle volumeestimates but this deviation would be easily noticedby eye and could be corrected.

The range of muscle sizes investigated in thestudies spans nearly the entire range of muscle sizesin the human body, indicating that this technique isaccurate for all muscles in the human body. One

The scanning of muscle todetermine its architecture has

a number of importantimplications“

“

FIGURE 6.

[LEFT]

Bland–Altmanplot of twomeasures ofmuscle volumefor the vastuslateralis

▼

FIGURE 7.

[RIGHT]

Bland–Altmanplot of twomeasures ofmuscle volumefor the firstdorsalinterosseous

▼

‰



REFERENCES

1 Bassey EJ, Fiatarone MA, O'Neill EF et al. Legextensor power and functional performance invery old men and women. Clin Sci 1992; 82:321–7.

2 Lund HL, Christensen L, Savnik A et al. Volumeestimation of extensor muscles of the lower legbased on MR imaging. Eur Radiol 2002; 12(12):2982–7.

3 Mitsiopoulos N, Baumgartner RN, HeymsfieldSB et al. Cadaver validation of skeletal musclemeasurement by magnetic resonance imagingand computerized tomography. J Appl Physiol1998; 85(1): 115–22.

4 Esformes JI, Narici MV, Maganaris CN.Measurement of human muscle volume usingultrasonography. Eur J Appl Physiol 2002; 87(1):90–92.

5 Daintith J, Nelson RD. The Penguin Dictionary ofMathematics. New York: Penguin Books, 1989.

6 Reeves ND, Maganaris CN, Narici MV.Ultrasonographic assessment of human skeletalmuscle size. Eur J Appl Physiol 2004; 91(1):116–18.

7 Scott SH, Engstrom CM, Loeb GE. Morphometryof human thigh muscles. Determination offascicle architecture by magnetic resonanceimaging. J Anat 1993; 182: 249–57.

8 Infantolino BW, Gales DJ, Winter S et al. Thevalidity of ultrasound estimation of musclevolumes. J Appl Biomech 2007; 23(3): 213–17.

9 Infantolino BW, Challis, JH. Estimating thevolume of the first dorsal interossoeus usingultrasound. Med Eng Phys 2011; 33(3): 391–4.

10 Yamaguchi GT, Sawa AGU. A survey of humanmusculotendon actuator parameters. In WintersJM, Woo SL. Multiple Muscle Systems:Biomechanics and Movement Organization. NewYork: Springer-Verlag, 1990; 717–73.

11 Klimstra M, Dowling J, Durkin JL et al. The effectof ultrasound probe orientation on musclearchitecture measurement. J Electromyogr Kines2007; 17(4): 504–14.

12 Bland JM, Altman DG. Statistical methods forassessing agreement between two methods ofclinical measurement. Lancet 1986; 1(8476):307–10.

13 Shrout PE, Fleiss, JL. Intraclass correlations:uses in assessing rater reliability. Pol Psychol Bull1979; 86(2): 420–28.

14 Trappe TA, Lindquist DM, Carrithers JA. Muscle-specific atrophy of the quadriceps femoris withaging. J Appl Physiol 2001; 90(6): 2070–74.

15 Aagaard P, Andersen JL, Dyhre-Poulsen P et al.A mechanism for increased contractile strength ofhuman pennate muscle in response to strengthtraining: changes in muscle architecture. JPhysiol 2001; 534(2): 613–23.

16 Delp SL, Bleck EE, Zajac FE et al. Biomechanicalanalysis of the chiari pelvic osteotomy. Clin OrthopRelat R 1990; 254: 189–97.

limitation is that ultrasound has a limited depth ofpenetration which may exclude being able to measuredeeper muscles on some subjects. However, most ofthe primary muscles that move the limbs would bevisible on most subjects using ultrasound. Datacollection took approximately 20 minutes for thevastus lateralis and less than 4 minutes for the firstdorsal interosseous. These scan times are similar toscanning times for other imaging modalities, albeitwith much cheaper equipment.

Implications

The scanning of muscle to determine its architecturehas a number of important implications. Withincreasing age there are significant decreases inmuscle volume; for example, for the quadricepsTrappe et al.14 reported a 43 per cent decrease inmuscle volume with age. Ultrasound imaging iscapable of tracking such changes. Strength training,which might be undertaken for sports trainingpurposes, the rehabilitation of muscle or to try toarrest muscle specific atrophy, also sees a change inmuscle volume. For example, Aagaard et al.15 reporteda change in muscle volume of the quadriceps of 10 percent as a consequence of 14 weeks of strength training.Once again ultrasound is capable of tracking suchvolume changes.

Applications and benefits

Models of the musculoskeletal system are becomingincreasingly popular for the analysis of humanmovement, in particular for making surgicaldecisions.16 The in vivo determination of particularmuscle architectural parameters using ultrasoundtherefore has implications for producing subject-specific muscle models within these models of themusculoskeletal system.

The determination of muscle volume is importantfor determining a component of muscle function.Experience indicates that imaging muscles of livesubjects produces better images than those obtainedfrom cadavers, which would lead to an even greateraccuracy of this method than the results that wedetermined in our studies.

Conclusion

Ultrasound is an ideal imaging modality for the in vivodetermination of muscle volume. Ultrasound does nothave the contraindications of imaging by MRI (metalimplants and claustrophobia, for example) or theradiation concerns of CT. Additionally, ultrasound ischeaper and more portable than MRI and CT, makingit an ideal imaging modality for a range of clinicalapplications, for example tracking musclehypertrophy or atrophy. n

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communication between the various branches of medicalphysics and the allied subjects; and to contribute to theadvancement of medical physics in all its aspects. Nowknown globally as a scientific, educational andprofessional organisation, and with more than 18,000members from 82 national bodies and six regionalorganisations, IOMP has plenty to celebrate. Its firstconference, in 1965, 2 years after its launch, took place inHarrogate, so it is fitting that it should return to the UK tomark its 50th anniversary in Brighton.

But ICMP2013 is not only about recognising historyand achievements to date. The theme of the conference is‘New Horizons – Global and Scientific’, and a carefullychosen mix of plenary sessions from world-leadingscientists, and proffered papers from the cutting edge ofresearch and development, will provide delegates withan abundance of information, stimulation and food for

he International Congress on Medical Physics(ICMP), taking place in Brighton in September 2013, will be a uniquely importantevent in the medical physics and clinicalengineering calendar. It will bring together

IPEM’s prestigious annual scientific meeting with thepremier international medical physics conference of theyear in one ambitious event. ICMP2013 also incorporatesthe 7th European Congress of Medical Physics; it will hostthe first ever retrospective exhibition on eminentcontributors to the field of physics; and it will be the focusof the 50th anniversary celebrations of the InternationalOrganization for Medical Physics (IOMP).

IOMP began in 1963 as a small coalition of just fouraffiliated national member organisations, but with somevery big ambitions. It aimed to do no less than to organiseinternational cooperation in medical physics; to promote

The majesticRoyal Pavilion,Brighton

▼

Peter Jarritt introduces the next International Congress on Medical

Physics taking place in Brighton and encourages you to register now!

ICMP2013: booking openfor a visit to Brighton

T‘ YOUR LETTERSScope welcomesyour feedback!



thought. On the Sunday, prior to the official openingceremony, there will be a whole day of educationalsessions, and the Hospital Physicists’ Association,celebrating its own 75th anniversary, is sponsoring apublic lecture by Peter Marsden from University CollegeLondon Hospital. IPEM’s hard-working outreachvolunteers will be there to ensure that school children canexperience some ‘hands-on’ science – and at the globalend of the scale, there will also be a stream on the sameday about medical physics in Africa.

Throughout the next three full days of the conference,delegates will have the choice of attending several busythemed streams, including novel medical devices;medical imaging and diagnostic techniques; cancertreatment methods and technologies; radiation protectionand dose reduction methods; and rehabilitation andassistive living technologies.

Between these sessions will be the chance to cometogether as a full conference for some unmissable plenarysessions. One of these will feature Molly Stevens,Professor of Biomedical Materials and RegenerativeMedicine at Imperial College, London, who will deliverthe prestigious Woolmer Lecture. Professor Stevens wasrecently recognised by the TR100, a compilation of the

BRIGHTON

Some of thesights that can beseen during avisit to Brighton,venue forICMP2013

▼

top innovators under the age of 35 who are transformingtechnology with their work.

As a bonus for IPEM members, the Institute’s AnnualGeneral Meeting will be held during the conference,giving members a chance to hear about, and vote on,some of the major changes proposed for the professionalbody. Members will also have a chance to meet theincoming President of IPEM, Professor Steve Keevil, as hetakes office. With a full social programme involving bothfish and chips and a visit to the Brighton sewers, and amajor commercial exhibition of industry partnersshowcasing the latest developments in the field, this willbe a conference with something for everyone.

Abstract submission is now open, bursaries are onoffer to help those struggling with funds to attend, andmore speakers are being added every week. To keep upwith the conference news, visit the dedicated website atwww.icmp2013.org, find it via the IPEM site www.ipem.ac.uk, or follow the conference on Twitter using#ICMP2013. Delegate booking opened in May, and IPEMmembers can book directly using the new online system.

Standing on a firm, 50-year foundation and lookingforward to new and exciting horizons, this event is goingto be the IPEM highlight of 2013 – don’t miss it! n

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For example, the partnership between UniversityCollege London, University College London Hospital,Royal Berkshire Hospital and Korle Bu Teaching Hospitalin Ghana is preparing for the arrival of Ghana’s first linearaccelerator in a public hospital. There are currently onlytwo treatment units publicly available to cover Ghana’spopulation of 26 million. In the UK this population wouldbe served by over 100 units. There are currently nopersonnel trained to use or maintain linacs in any publichospital in Ghana.

The projects were announced by Lord Nigel Crisp lastSeptember and we look forward to tracking their progresshere in Scope.

ospitals in low- and middle-income countriesfrequently report the poor state of medicalequipment as being a key challenge they face indelivering essential services. WHO statistics arealarming. It is estimated that between 50 and 80

per cent of medical equipment is out of service in theseregions. One of the biggest reasons for this is the lack oftrained maintenance personnel. The Tropical Health andEducation Trust, a specialist global health organisation thateducates, trains and supports health workers throughinstitutional partnerships, has introduced a newprogramme to support training in this crucial area.

With funding provided by the Department forInternational Development, qualified biomedical engineersfrom the UK are being engaged as global health volunteersto share their skills and support their colleagues in Ghana,South Sudan, Ethiopia, Uganda and Zambia.

Medicalequipmenttraining in Zambia

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Shauna Mullally reports on an innovative new programme to improve the

maintenance and management of medical equipment in developing countries

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H


‘ MORE INFORMATIONFor more information please visit: http://www.thet.org/hps/news/thet-launches-medical-equipment-programme


he European Congress for Thermologyforms a key international meeting inthe field of medical thermography. It is

held every 3 years and this year it washosted by the Faculty of EngineeringUniversity of Porto (FEUP), Portugal, withProfessor Joaquim Gabriel and Dr RicardoVardasca the main meeting organisers. Onday 1, of the 4-day meeting, there was a pre-congress certificated training course inmedical thermography followed by theEuropean Association of Thermology (EAT)General Assembly meeting. Days 2 and 3accommodated the main scientific sessions,and day 4 focussed on a social eventcomprising a day-long boat trip along thedramatic landscape of the River Douro. Thecity of Porto is shown in figure 1.

A total of 70 delegates were in attendance;most were European but there were alsoresearchers from the US, Japan and SouthAmerica (figure 2). There were four keynotepresentations and approximately 60 furtheroral and poster presentations. The abstractsfor the presentations at the meeting havebeen published in the journal ThermologyInternational (2012; 22(3)) and the full paper,in digital format, as the Appendix I.

The EAT Certified Thermography Courseis a unique training course in medicalthermography and covers topics includingheat exchange and IR radiation, thermalphysiology, equipment operation, medicalreasons for temperature changes,physiological provocation tests, imageanalysis and reporting, examples of

applications in medical thermography andeducational resources in medical imaging. Apractical session on thermal imagingmethods was also included (figure 3). Thesetraining courses tend to be held infrequentlybut further information can be obtained fromDr Vardasca and Professor Francis Ring(University of Glamorgan) on request.

The scientific sessions held from Day 2opened with the first keynote presentationgiven by Professor Ring entitled ‘The historyof thermology and thermography – thepioneers and milestones’ (figure 4). This wasa fascinating overview with historicalperspectives from the sixteenth century todate. Thermal imaging has come a long waysince William Herschel identified dark heatin 1800, through Carl Wunderlich’s thesis on

T

FIGURE 1. The old town in the city of Porto, home to the conference

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Allen and How

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12TH CONGRESS OF THE EUROPEANASSOCIATION OF THERMOLOGY (EAT) DR JOHN ALLEN Medical Physics, Freeman Hospital, Newcastle upon Tyne

PORTO, PORTUGAL5th–8th September2012 ‘

MEETING REPORTS

‘ MEETING REPORTS ARE GOING ONLINE

This means that authors will not have to wait for the printed magazine to come out before their reports are availableto read. This issue of Scope will be the last to contain printed reports – these reports will also be the first to goonline at the new site: http://www.ipem.ac.uk/ConferencesEvents/Conferencereportsandabstracts.aspx

Angela Cotton, Scope Meetings Report Editor


clinical thermometry and the continualmonitoring of human body temperature, tothe development of thermal imagingsystems in the twentieth century givingradiometric temperature measurementcapability. The roles of digital computingand image processing were highlighted inthe stages of development up to today’shigh-performance portable thermal camerasystems. Professor Ring then focussed onclinical applications in rheumatology,highlighting the necessity forstandardisation with ‘standardised views’and emphasis on ‘best practice’. These areimportant considerations to help reduceuncertainty in measurement, and are vitalfor follow-up assessments when evaluatingthe response to drug therapy. Otherapplications of clinical thermographyinclude fever screening, airport security anddetection of infection. Fever screeningstandards are now described in an ISOStandard (ISO/TR 13154:2009). Overall, Ifound a vast wealth of information wasconveyed in the lecture – not surprising as itrepresented an overview of 50 years ofProfessor Ring’s contribution to the field.

Thermal physiology

The first main topic of the scientific lectureprogramme was thermal physiology. Theopening oral presentation discussed theuncertainty in measurements whenassessing core body temperature usingclinical spot temperature thermometers(Märtha Sund-Levander, Jönköping &Futurum, Sweden). The speaker raisedimportant questions about the definition ofcore temperature, normal temperatureranges needing to be specified for differentbody sites, and the utility of using eachpatient as a control to track their ownrelative temperature changes over time.There were then two presentations on coretemperature which explored the use of

weighted formulae for estimating coretemperature (Emília Quelhas Costa,University of Porto, Portugal, and DavidPascoe, Auburn University, AL, USA). JoanaGuedes (University of Porto, Portugal) thendescribed the use of a state-of-the-artclimatic chamber for the assessment ofpsychosocial responses to varyingtemperature and humidity levels. JohnAllen (Newcastle upon Tyne) presentedwork on the standardised testing of skintemperature and microvascular blood flowchanges (using photoplethysmography)with controlled induced gasp manoeuvre toproduce repeatable vasoconstrictor waves,quantifying the expected normal ranges forthe magnitudes and relative delays betweenphysiological signals.

The second and main topic for thescientific lecture programme wasapplications of clinical thermography with awide range of medical conditions covered,including: staging patients with complexregional pain syndrome (CRPS) (TimothyConwell, Colorado Infrared Imaging Center,Denver, CO, USA, and Luigi Laino, RomaStudio Dermatologico Venereologico, Rome,Italy), hand–arm vibration syndromeassessment (Ricardo Vardasca, University ofPorto, Portugal), whole body vibration andskin temperature of the lower extremities inhealthy subjects (Adérito Seixas, Universityof Porto, Portugal), infantile hemangiomatreatment by propanolol (Francis Ring),abdominal skin circulation pre- and post-plastic surgery (Cristina Vicari Nogueria,

Barcelona Autonoma University, Spain),detection of subclinical varicocele in thescrotum (Arcangelo Merla, G. d'AnnunzioUniversity, Italy), highly focalisedthermotherapy in the treatment of solidtumours (Ana Portela, University of Porto,Portugal), application of cold provocation forbreast cancer screening (Piotr Przymusiala,Termowizja S.A., Lodz, Poland), feverscreening (António Cardoso, CATIM,Portugal), Graves’ orbitopathy (John Allen),effect of yoga and swimming on the bodytemperature of pregnant women (ManuelSillero-Quintana, Universidad Politécnicade Madrid, Spain), mother and child insynchrony: thermal facial imprints ofautonomic contagion (Arcangelo Merla),assessing the effectiveness in reducing post-operative swelling with facial cooling byhilotherapy in a pilot study of healthycontrols (Kevin Howell, Royal Free andUniversity College Medical School, London),detecting hypothermia (H. Usuki, Universityof Kagawa, Japan), bone temperatureevolution (António Silva, University ofPorto, Portugal), transfemoral amputeesstump and socket (Emilia Mendes,University of Strathclyde) and a literaturereview of the temperature of the human knee(Kurt Ammer, Österreichische Gesellschaftfür Thermologie, Austria).

A keynote clinically-focussed talk wasthen given by Professor James Mercer(University of Tromsø, Norway) entitled‘Thermography in plastic surgery’. Hedescribed the use of thermal imaging in pre-,intra- and post-surgical monitoring of skinflap graft perfusion. Pre-surgicalthermography, with local skin cooling from afan device, was shown to help the clinicianlocate subcutaneous graft ‘perforator’vessels for graft transfer. The key advantagesof using thermography over Dopplerultrasound were given to add extra weightfor the technique in theatre. Fan cooling was

FIGURE 2. Some of the delegates outside thePorto Casa da Musica state-of-the-artbuilding

FIGURE 3. Practical session on medicalthermal imaging at the Faculty of EngineeringUniversity of Porto (FEUP), Portugal

FIGURE 4. Professor Francis Ring giving theopening keynote scientific lecture on medicalthermography

Image ©

Professor Joaquim G

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These are importantconsiderations to helpreduce uncertainty in

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used to enhance the thermal contrast toimprove technique sensitivity. Post-operativemonitoring of a graft flap area withthermography could also give early feedbackon the complications that can require urgentreconstructive surgery. A key physiologicalfeature to look for as an indication of likelygraft success was the presence of a skintissue hyperaemia at between 2 and 6 dayspost-surgery.

Thermal imaging methods

The third topic of the scientific programmewas thermal imaging methods, imageanalysis, calibration and quality assurance,commencing with a lecture on theassessment of calibration and evaluationprocedures for thermal imaging metrology atthe National Physical Laboratory in the UK(Rob Simpson, NPL, Teddington). A range ofmethodological papers then followedincluding integrating medical thermographyinto RIS using the DICOM standard (ToméVardasca, University of Porto, Portugal), thehistographic method as a tool for thermalimage processing (Imre Benkö, BudapestUniversity, Hungary) and reliability andreproducibility of skin temperature ofoverweight subjects using infraredthermography software (Ismael Fernández-Cuevas, Universidad Politécnica de Madrid,Spain). I then presented a paper describinghis experiences over a decade in thedevelopment of a clinical vascular opticsmeasurement facility. Example thermogramscollected in the Newcastle imaging facilityare shown in figure 5.

The final topic was the application ofthermal imaging to equine medicine. SimoneWestermann (University of Vienna, Austria)opened the session with the keynote lecture‘Thermography in equine medicine and thedifferent environmental factors on thethermographically determined temperature’.Similar to humans, horses also demonstrate

thermal symmetry in health. Horses alsohave an emissivity value for their surfacetissue close to 1, similar to human skin. DrWestermann summarised the main standardthermography views used in horseassessments, with standard distances, choiceof camera angle, time of day formeasurements and the practicalconsiderations for keeping the horse stillduring imaging. A suggested protocol wasgiven, choosing a thermal ambient of close to20ºC, avoiding measurements in direct andstrong sunlight, choosing an environmentwith minimal local air flow, and not to takemeasurements when the horse’s coat is wet.Artefacts can result from dirt, scar tissue andwith excess hair length. A key application forthermal imaging is to detect tissueinflammation from warm joints. DrWestermann noted that a thermal asymmetryof >1ºC may indicate pathology. RamPurohit (University of Auburn, AL, USA)then gave two talks: 'The effect of highregional nerve block on the thermographicpatterns in the limbs of horses' and 'Thelegality associated with the use of infraredthermal imaging in veterinary medicine'.Maria Soroko (Wroclaw University, Poland)closed the session with a talk on the use ofthermography to evaluate musculoskeletalresponses in the backs of young racehorses inadvanced levels of training.

Events involving alcohol

In setting the scene for the main social eventsinvolving alcohol, the fourth and finalkeynote lecture was presented by OlgaGrant (National University of IrelandMaynooth, County Kildare, Ireland) entitled‘Thermography in viticulture’. She provideda fascinating overview of wine productionand in particular hydration of the vine andhow this can be remotely monitored to helpmaximise yield. It is important to detectplant stress early, and using remote optical

monitoring can help facilitate precisionirrigation, especially in areas of reducedwater supply. Dr Grant described thepractical options available to assess vastland vine areas, including the thermalimaging of vine rows remotely from a lightaircraft. She also discussed current work ingenetic improvement of the vine to optimisegrowth and subsequent yield.

The congress dinner was held at Taylor’sPort and Wine Cellar in Porto. Delegateswere invited to taste one of their fine portdrinks whilst warmly receiving musical andvisual entertainment from a violinist –Ianina Khmelik (Russia) – playing acontemporary piece, artistically arranged tohave live thermal images of her projectedwhilst she played. Several prizes wereawarded at the dinner: best overall oralpresentation for ‘Mother and child insynchrony: thermal facial imprints ofautonomic contagion’ (Arcangelo Merla,University Chieti-Pescara, Italy), beststudent oral presentation (the Francis Ringprize) for ‘The highly focalisedthermotherapy in the treatment of solidtumours: temperature monitoring usingthermography’ (Ana Portela, University ofPorto, Portugal) and best posterpresentation (the Kurt Ammer Prize) for ‘Amethod for whole-body human skintemperature mapping’ (Damien Fournet,University of Loughborough).

Overall, the congress was well organisedand well attended. I found attending themeeting a fabulous experience and I thankIPEM for their generous contribution to mytravel costs from their IPEM Travel BursaryAward to allow me to make the trip. It wasalso a great pleasure to visit the city of Portoand to experience the culture and greatwarmth of the people there. It was certainlyworth going. I have also made newprofessional contacts in medicalthermography. n

FIGURES 5A, B AND C. Example thermal images of (a) patient with diagnosed complex regional pain syndrome in the lower limbs, (b) active stagethyroid eye disease and (c) skin fat tumours

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n my job at the University CollegeLondon Hospital I have been heavilyinvolved in the department’s

neuroimaging services and I havedeveloped a keen interest within this field.The department currently performs arange of brain imaging procedures,including 18F-FDG PET and 99mTc-HMPAOSPECT for epilepsy, 18F-FDG and 18F-florbetapir PET for dementia and 123I-FP-CIT SPECT for Parkinsonian syndromes. Anumber of tracers are also used foroncological brain applications (e.g. 18F-Choline and 68Ga-octreotate). In my role asa clinical scientist I perform routine,development and research work withinthis field.

In 2012 I was fortunate to receive anIPEM/AAPM travel award. This enabledme to travel to the United States for 3weeks in October 2012, visiting high-profile centres performing PETneuroimaging research.

Imaging in Alzheimer’s disease

Alzheimer’s disease is currently affectingabout 5.4 million Americans, with about 45per cent of the population over the age of85 being affected. With the baby boomgeneration now reaching the age of 60 andthe expected increase in life expectancy, itis projected that between 11 and 16 millionAmericans over the age of 65 will have thedisease in 2050. The burden this will placeon the healthcare system will beenormous. The projected numbers are,however, given with the condition ‘barringthe development of medicalbreakthroughs to prevent, slow or stop thedisease’ and research is currently ongoingworldwide to tackle this.1

A hallmark of Alzheimer’s disease isthe formation of amyloid plaques in thebrain. According to the amyloid cascadehypothesis the formation of amyloidplaques is considered a key pathogenicevent of the disease, with accumulation in

the brain starting years prior to clinicalsymptoms.2 β-amyloid (Aβ) is the mainconstituent of amyloid plaques, previouslyonly visible microscopically in the brainduring post mortem examination. PETtracers have, however, recently beendeveloped enabling in vivo imaging of Aβand the potential for early detection ofAlzheimer’s disease.3

Pittsburgh

I spent a week in the PET imaging researchcenter at the University of PittsburghMedical Center under the supervision ofProfessor Julie Price. Current research topicsfor this group include imaging inAlzheimer’s disease, neuroreceptor imaging,evaluation of novel oncology tracers andevaluation of efficacy of drug therapy intuberculosis patients. The centre becameknown worldwide for the development ofthe 11C Pittsburgh Compound-B (PiB) tracer,which can be used for imaging inAlzheimer’s disease. The tracer binds tofibrillar Aβ deposits in the brain at PETligand concentrations. The proof of conceptstudy was published in 2004,4 showinggroup differences in tracer uptake betweenhealthy controls and subjects withAlzheimer’s disease. A number of studieshave since been published by the Pittsburgh

group and others, further validating thetracer and exploring its potential clinicalusage areas.

In Pittsburgh I mainly concentrated onlearning about the validation workperformed when developing the PiB tracer,in particular the work carried out to findvalid methods for Aβ depositionquantification. To investigate thecharacteristics of PiB amyloid binding, thegroup initially used a fully quantitativeapproach.5 Cognitively healthy controls,subjects with mild cognitive impairment andsubjects with Alzheimer’s disease wereintravenously injected with 11C-PiB, followedby dynamic PET data acquisition and arterialplasma sampling over 90 minutes. Theplasma samples were used to measure thetracer input to tissue, while manual regionsof interest were drawn over grey and whitematter areas of the brain to assess the tissueresponse to this input. Kinetic componentswere found using spectral analysis,supporting the use of a two-tissue, fourparameters compartmental model. This typeof compartmental model was also shown tobest describe the acquired data (figure 1).Distribution volume ratios were calculatedfrom model parameters, giving aquantitative measure of the tracer binding invarious brain areas (figure 2).

I

FIGURE 1. Example curve fit (solid lines) obtained for the two-tissue, four parameterscompartment model from regions of interest drawn for the posterior cingulate (grey circles)and cerebellum (white circles). Image courtesy of Prof. Julie Price. Adapted by permission fromMacmillan Publishers Ltd, J Cerebr Blood F Met 2005; 25: 1528–47, copyright 2005

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A hallmark ofAlzheimer’s disease is

the formation of amyloidplaques in the brain“

“

PET NEUROIMAGING RESEARCH IN THE US: A 3-WEEK RESEARCH VISITTHERESE SÖDERLUND Nuclear Medicine, University College London Hospital

UNITED STATESOctober 2012

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The group then proceeded to look atsimplified quantitative methods as describedby Lopresti et al.6 This is essential for routineuse, both in terms of easier implementationand improved patient compliance. A varietyof approaches were evaluated, includinglooking at the need for arterial bloodsampling, the possibility of using a shortenedscan time and the use of semi-quantitativemeasures. Each method’s performance wasevaluated in terms of bias, test-retestvariability, effect size and inter-subjectvariability. Encouragingly, the use of a latesingle-scan time and semi-quantitativeanalysis of tracer binding in the form of astandardised uptake value ratio proved togive the largest group differences with goodinter-subject and test-retest variability. Thiswas however shown to come at the cost ofintroducing a strong positive bias in the data.Overall, it was highlighted that eachquantitative or semi-quantitative method hasits advantages and disadvantages, with themethod of choice being highly dependent onthe clinical application.

The group is involved in a number oftrials looking at the clinical utility of amyloidPET tracers. Some of the current projects thatI was able to gain insight into were:n Assessment of particular sub-groups aslisted below. These groups are imaged tostudy amyloid plaque deposition in its earlystages, before the onset of clinical symptoms.A common aim is to follow these subjects asthe disease develops/progresses, with thehope to gain increased understanding of therole of amyloid plaque deposition inAlzheimer’s disease and also to aid futuretherapy response studies:

– Mild cognitive impairment. Subjectswith mild cognitive impairment havememory deficits that do not significantlyimpact their daily function. The conversionrate to Alzheimer’s disease is about 10–20per cent each year.

– Familiar Alzheimer’s disease. This is aninherited form of Alzheimer’s disease inwhich subjects are affected early in life (<65years of age).

– Down’s syndrome. Subjects withDown’s syndrome have an increased risk ofdeveloping Alzheimer’s disease comparedwith the general population. The reason forthis is not completely known, but it has beenshown that the amyloid precursor protein,thought to be a driving factor of amyloidplaque deposition in the brain inAlzheimer’s disease, is produced from agene on chromosome 21, the trisomy ofwhich leads to Down’s syndrome.

– Cognitively normal healthy controls. Ithas been shown that cognitively healthyelderly people can have amyloid plaquedepositions in the brain without showingany clinical signs of Alzheimer’s disease.The clinical implication of this is not yetunderstood.n Looking at post-mortem amyloid load andcomparing histopathological results withfibrillar Aβ burden seen on 11C-PiB images ofthe same subjects.n Evaluation of 18F amyloid tracers. Anumber of 18F-based tracers are currentlybeing evaluated with their performancecompared to the 11C-PiB compound. Oneclear advantage of 18F tracers would be thatan on-site cyclotron is not needed, enablingmore widespread usage.

Berkeley

I also spent a week at the Jagust Laboratoryin Berkeley, California, which is a jointresearch programme involving the UCBerkeley Helen Wills Neuroscience Institute,the UC Berkeley School of Public Health andthe Lawrence Berkeley National Laboratory(figure 3). The lab is led by Professor WilliamJagust and specialises in the study of brainageing and dementia using PET and MRimaging, neuropsychology and cognitiveneuroscience. The data analysis methodsused tend to be automated voxel-basedmethods such as Statistical ParametricMapping.7 Within the lab there are a numberof ongoing projects investigating the usage ofthe 11C-PiB compound and during my visit Iwas able to learn more about some of theseresearch topics.

The lab runs the Berkeley Aging CohortStudy, enrolling cognitively normal elderlyvolunteers from the local area. The study ofthe cognitive healthy elderly is important asit has been found that a large proportion ofthese subjects have Aβ brain depositionsalthough not showing any clinical signs ofAlzheimer’s disease. To address this, theBerkeley Aging Cohort Study is set up as alongitudinal study of healthy elderlyvolunteers undergoing cognitive tests andimaging in the form of 11C-PiB PET/CT, 18F-FDG PET/CT and structural and functionalMRI. The group is hoping to answerquestions such as why some cognitivelynormal subjects have high levels of Aβdeposition and whether these cognitivelynormal subjects are on a trajectory towardsdeveloping Alzheimer’s disease. A recentlypublished paper from the study compared


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FIGURE 2. 11C-PiB binding for a subject with Alzheimer’s disease (AD)and a healthy control (control). As typical in Alzheimer’s diseaseincreased PiB binding is seen in the frontal cortex, posteriorcingulated gyrus and precuneus. Image courtesy of Prof. Julie Price

FIGURE 3. View towards the San Francisco Bay and the Golden GateBridge from the Lawrence Berkeley National Laboratory situated inthe hills above the UC Berkeley campus

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lifetime cognitive and physical engagementwith 11C-PiB binding.8 It was shown thatsubjects with greater early- and mid-lifecognitive activity had lower levels offibrillar Aβ brain depositions. Anassociation between physical exercise and11C-PiB binding, however, was not found.

A second large-scale study that theJagust lab is involved in is the Alzheimer’sDisease Neuroimaging Initiative (ADNI).9

This is a longitudinal multi-centre studylooking at normal cognitive ageing, mildcognitive impairment and Alzheimer’sdisease. The goal is to evaluate imagingbiomarkers (MRI and PET) and otherbiomarkers (e.g. coming from CSF andblood tests), aiming to identify the bestmethod of analysis for trackingAlzheimer’s disease over time. The hope isalso that this will aid clinical drug trialsthat use these biomarkers as outcomemeasures. As the PET core centre the Jagustlab is responsible for ensuringstandardisation of PET data acquiredacross the 50 sites participating in thestudy. This includes the major task ofperforming quality control of all acquiredPET data, e.g. assessing each scan’ssinogram for artefacts and all reconstructedimages for motion.

Imaging in Parkinsonism

Parkinsonism is an umbrella term describinga number of conditions sharing clinicalsymptoms such as tremor, muscle stiffnessand slowness of movement. Of these,idiopathic Parkinson’s disease and atypicalParkinsonian syndromes such as multiplesystem atrophy, corticobasal degeneration,Lewy Body dementia and progressivesupranuclear palsy have the commoncharacteristic of causing a dopaminedeficiency in the basal ganglia. Althoughassessment of clinical symptoms is usuallysufficient for a diagnosis, imaging can behelpful in difficult cases. Commonly, PETand SPECT tracers targeting different partsof the dopaminergic pathway are used todifferentiate between, for example, essentialtremor and Parkinson’s disease, and LewyBody dementia and Alzheimer’s disease.10

New York

I spent a further week at the FunctionalBrain Imaging Laboratory at the FeinsteinInstitute for Medical Research on LongIsland, New York, under the supervision ofProfessor David Eidelberg. This centreperforms work in developing novel PET andMR imaging techniques to characteriseneural circuits in neurodegenerativedisorders. Current research areas includenervous system diseases such as Parkinson’sdisease, Huntington’s disease and thedementias. In contrast to many centres usingtracers directly targeting the dopaminergicpathway, the lab at the Feinstein Institute isdeveloping the usage of 18F-FDG PET forimaging in Parkinsonism. Being a glucoseanalogue, FDG uptake reflects the brain’s

metabolism and as such synaptic integrity.During my week at the Feinstein Institute Iconcentrated on learning about the principalcomponent analysis method used by the labfor data analysis and its potential clinicalapplications.

The lab uses the hypothesis that patientswith Parkinsonism show a changedmetabolic pattern of 18F-FDG brain uptakecompared to healthy subjects. Data analysisis performed by using a type of principalcomponent analysis called Scaled SubprofileModelling.11 This is a completely data-drivenanalysis method in which the dataset is firsttransformed to only look at variables thatcapture most of the variance. The principalcomponents of the dataset are then found,which in essence are linear functions lookingat the inter-correlation between datasetregions (voxels or regions of interest). Thegroup is therefore taking a functionalintegration approach to explain brainfunction, in which function is seen as aproduct of interacting brain areas withinnetworks. This can be contrasted to the moretraditional approach of functionalsegregation, where brain function isexplained as being localised to specific areaswithin the brain.

By using test populations of healthycontrols and subjects with knownParkinsonism the group has been able toidentify and validate specific metabolicpatterns in Parkinson’s disease and atypicalParkinsonian syndromes.12 These patternscan then be used to score single subject scans,with z-scores calculated to describe themagnitude of the expression of a particularnetwork that the subject is showing. Current

FIGURE 4A. Brooklyn Bridge, one of the oldest suspension bridges in the US, connecting Manhattan and Brooklyn across the East River

I concentrated onlearning about the

principal componentanalysis method“

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projects that I was able to learn moreabout during my week at the lab include:n Validation of the analysis method forclinical use. For this purpose the group atthe Feinstein Institute is collaborating withgroups in Germany, Holland and China.n Assessment of pattern expression inpatients with REM sleep disorders. As alarge portion of these subjects go on todevelop Parkinson’s disease the metabolicpattern observed has the potential to beused as a biomarker for patients with REMsleep disorders, potentially being used tocalculate the likelihood of a patientdeveloping Parkinson’s disease.n Utility of metabolic patterns in treatmentresponse studies.

Conclusion

The travel award has significantly expandedmy knowledge of current PETneuroimaging research topics, in particularin Alzheimer’s disease and Parkinsonism.From a clinical scientist’s perspective it hasbeen particularly interesting to learn moreabout the different data analysis approachestaken by the research groups I visited. Thegroup in New York is, for example, using acompletely data-driven method, with thedata analysed using a type of principalcomponent analysis, followed by anexplanation of the outcome using knownclinical attributes of test populations. InPittsburgh the approach, on the other hand,is to use hypothesis-driven data analysismethods, e.g. with regions of interest drawnover areas known to be affected by

Alzheimer’s disease followed byquantification of tracer uptake usingcompartmental modelling. The differentdata analysis methods dictate whether thecentres use segregated or integratedapproaches to explain brain function, withthe Aβ uptake assessments performed inPittsburgh and Berkeley in general using asegregated approach and the principalcomponent analysis used at the FeinsteinInstitute assuming networks within thebrain and hence an integrated approach.During my visit I was also able to learnmore about different PET systemsavailable on the market, includinginteresting discussions with the team inPittsburgh about the PET/MR scannerthat has recently been installed at both theUniversity of Pittsburgh Medical Centerand also the University College LondonHospital.

In addition to the professional learningoutcomes, the travel award has enabledme to meet many interesting people andto visit new places. Although I stayedclose to the centres I visited, I was able toexplore Manhattan, Brooklyn and SanFrancisco during evenings and weekends(figure 4).

I would like to extend my thanks toProfessors J. Price, W. Jagust and D.Eidelberg for welcoming me to theirdepartments. I am also very grateful forthe support from my colleagues at theUniversity College London Hospital. Aspecial thanks to Dr J. Dickson for hisencouragement and help. n

REFERENCES

1 Alzheimer’s Association. 2012Alzheimer’s disease facts and figures.Alzheimers Dement 2012; 8: 131–68.

2 Jack CR, Knopman DS, Jagust WJ etal. Hypothetical model of dynamicbiomarkers of the Alzheimer’spathological cascade. Lancet Neurol2010, 9: 119–28.

3 Herholtz K, Ebmeier K. Clinicalamyloid imaging in Alzheimer’sdisease. Lancet Neurol 2011, 10:667–70.

4 Klunk WE, Engler H, Nordberg A et al.Imaging brain amyloid in Alzheimer'sdisease with Pittsburgh Compound-B.Ann Neurol 2004, 55: 306–19.

5 Price JC, Klunk WE, Lopresti BJ et al.Kinetic modeling of amyloid binding inhumans using PET imaging andPittsburgh Compound-B. J CerebrBlood F Met 2005, 25: 1528–47.

6 Lopresti BJ, Klunk WE, Mathis CA etal. Simplified quantification ofPittsburgh Compound B amyloidimaging PET studies: a comparativeanalysis. J Nucl Med 2005, 46:1959–72.

7 Friston KJ. Statistics I: experimentaldesign and statistical parametricmapping. In Toga AW, Mazziotta JC.Brain Mapping: The Methods. London:Academic Press, 2002; 605–30.

8 Landau SM, Marks SM, Mormino EC etal. Association of lifetime cognitiveengagement and low β-amyloiddeposition. Arch Neurol-Chicago 2012,69: 623–9.

9 Mueller SG, Weiner MW, Thal LJ et al.Ways toward an early diagnosis inAlzheimer’s disease: the Alzheimer’sdisease neuroimaging initiative (ADNI).Alzheimers Dement 2005, 1: 55–66.

10 Cummings JL, Henchcliffe C, SchaierS et al. The role of dopaminergicimaging in patients with symptoms ofdopaminergic systemneurodegeneration. Brain 2011, 134:3146–66.

11 Spetsieris PG, Eidelberg D. Scaledsubprofile modeling of resting stateimaging data in Parkinson’s disease:methodological issues. Neuroimage2011, 54: 2899–914.

12 Eidelberg D. Metabolic brain networksin neurodegenerative disorders: afunctional imaging approach. TrendsNeurosci 2009, 32: 548–57.

FIGURE 4B. Lower Manhattan as seen from Brooklyn

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he need for practical and accurate 3Dradiation dosimetry techniques is apriority in support of the rapidly

advancing demands of modern high-precision radiation technology and clinicaltechniques. The IC3DDose conference is apremier forum held biennially to discussthese issues, with the key objectives to:n enhance the quality and accuracy ofradiation therapy treatment throughimproved clinical dosimetry;n investigate and understand thedosimetric challenges of modernradiotherapy;n discuss latest research and developmentsin 3D and advanced dosimetry, andn energise and diversify dosimetryresearch and clinical practice byencouraging interaction and synergybetween advanced, 3D and semi-3Ddosimetry techniques.

The IC3DDose conference seriesoriginated as a specialist forum to discussgel dosimetry, the 1st InternationalWorkshop on Radiation Therapy GelDosimetry being held in Kentucky in 1999.While maintaining a strong focus on geldosimetry, and keeping to the ethos ofdiscussing basic science through to clinicalapplications, the conference now includes awide range of radiation dosimetrymethods.

Overview of the conference

I was very fortunate to receive £1,000 offunding from the IPEM bursary award,along with financial support fromAdvanced Materials Group, Ashland Inc.,Wayne, NJ, USA, to assist with the costs ofpresenting my own research into theapplication of Gafchromic EBT3 filmdosimetry for HDR brachytherapy at themeeting. This is work involving themultichannel analysis of radiochromic filmto measure semi-3D dose distributions closeto clinical HDR brachytherapy treatmentapplicators. This is also related to aproposed UK national audit of HDRbrachytherapy.

The meeting was expertly organised byDavid Thwaites, Director of the Institute ofPhysics at the University of Sydney, CliveBaldock, Dean of the Faculty of Science atMacquarie University and their organisingteam. Even a major loss of power at the

conference venue didn’t faze them (much)and the meeting resumed in an alternative5* hotel after the briefest of pauses!

Around 120 people from across theworld attended the 4-day conference, whichcomprised a full programme of 12 sessionswith 12 invited speakers, topic reviews,over 90 individual proffered presentationsand a poster session. There was also spacefor a couple of discussion sessions and amanufacturer/sponsor exhibition. Allpapers presented at IC3DDose will bepublished in the Journal of Physics:Conference Series in due course. This willinclude the invited reviews that were givenat the conference: gel dosimetry (Kim

McAuley, Queens University, Canada), theneed for 3D dosimetry (Stine Korreman,Roskilde University, Denmark), solid statedosimetry (Peter Metcalfe, University ofWollongong, Australia), dosimetry withoptical readout (Kevin Jordan, University ofWestern Ontario, Canada), 3D dosimetryapplications (Mark Oldham, DukeUniversity, USA), EPID pre-treatmentdosimetry (Peter Greer, University ofNewcastle, Australia), EPID in vivodosimetry (Ben Mijnheer, NKI, TheNetherlands), QA of external beamradiotherapy from 2D to 4D (VladimirFeygelman, Moffit Cancer Center, USA),scintillation dosimetry (Luc Beaulieu,CHUQ, Canada), MRI optical and x-ray CTevaluation (Yves de Deene, University ofGhent, Belgium, Simon Doran, Institute ofCancer Research, Sutton, and AndrewJirasek, University of Victoria, Canada),dosimetry for audit and clinical trials(Tomas Kron, Peter MacCallum CancerCentre, Australia), reliability of 3D gels(Yves de Deene), analysis of 3D dose andgamma evaluation (John Schreiner, SEOntario Cancer Centre, Canada), dosimetryof CBCT (Jonathan Sykes, Leeds/St James’Institute of Oncology), accuracy requiredand achievable (David Thwaites,

University of Sydney, Australia, figure 1)and the dosimetry requirements for 4Dradiotherapy (Paul Keall, University ofSydney, Australia).

Of course, with such a diverse andcomprehensive meeting it is impossible toreview all contributions in this meetingreport, so below are is very limitedselection of some of my highlights fromthe meeting.

Stine Korreman

Stine Korreman provided a review of thetypes of 3D dosimetry in clinical practiceand usefully provided a new definition forterms. She divided 3D dosimetry intothree categories; true 3D, semi-3D andvirtual 3D. Virtual 3D involves the use ofmeasurement arrays either before or afterbeam entry in the patient or phantom,whereas semi-3D involves the use ofmeasurement arrays in phantomsmimicking the patient. True 3D involvesthe measurement of dose in a volumemimicking the patient. Korremandiscussed the advantages and limitationsof each category and gave a simple butoften forgotten conclusion, that the choiceof measurement method in a given casedepends on the aim of the measurement,and all may be valid. It was suggested thatvirtual 3D dosimetry is the preferredfuture for clinical applications, verifyingdelivery is correct and enabling adaptiondecisions.

Fredrik Nordström

Fredrik Nordström (Skane UniversityHospital and Lund University, Sweden)presented a 4D dosimetry system. Thisincluded a method for calculation of 3Dreference absorbed dose matrices at everycontrol point of the delivery using aclinical treatment planning system. Thegamma evaluation method was extendedto incorporate the fourth dimension of theTPS calculated dose distributions, andtermed ‘hyper-gamma’. The applicationsof the 4D dosimetry concept on pre-treatment quality control and real-time invivo dosimetry were demonstrated.

Peter Metcalfe

Peter Metcalfe presented a number ofprototype novel radiation dosimeters

T

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Even a major loss ofpower at the conferencevenue didn’t faze them

(much)!““

RESEARCH AND DEVELOPMENTIN 3D RADIATION DOSIMETRYA.L. PALMER Head of Radiotherapy Physics, Portsmouth Hospitals NHS Trust

SYDNEY,AUSTRALIA4th–8th November2012 ‘

MEETING REPORTS


developed within the Centre forMedical Radiation Physics. This includedtwo silicon array detectors, the magicplateand dose magnifying glass. The primaryfocus of these two detectors is high spatialand temporal resolution dosimetry forIMRT. The third detector discussed wasthe MOSkin, which is a high spatialresolution detector based on MOSFETtechnology, its primary role in in vivodosimetry. The fourth detector system wasthe BrachyView, which is a high-resolutiondose viewing system based on Medipixdetector technology.

Unjin Yeo

Unjin Yeo (RMIT University, Australia)discussed the application of deformablegel dosimetry. Inter- and intra-fractionalvariation in anatomic structures is asignificant challenge in contemporaryradiotherapy and Yeo described theimplementation of a novel deformable geldosimetry system (termed ‘DEFGEL’) forapplication to external beam RT andbrachytherapy experimentalmeasurements. Complex/redistributeddose distributions due to applieddeformations were readily observed andthe discrepancies relative to a control casewith an absence of deformation could bequantified. This work is proposed to haveuses in the validation of deformable imageregistration algorithms, deformable dosecalculation algorithms and qualityassurance of motion compensationstrategies in radiotherapy.

Boyd McCurdy

Boyd McCurdy (University of Manitoba,Canada) gave a valuable overview ofEPID dosimetry, a-Si detectors, dosimetriccharacteristics and remaining limitations.There is strong continued interest in usingEPID dosimeters for patient treatmentverification. There are three distinctmethods; non-transmission dosimetry,transmission/transit dosimetry and in vivodosimetry, the latter being thedetermination of dose within the patientby measurements performed duringtreatment. McCurdy thought it issomewhat surprising that manufacturershave not yet provided commercialsystems to fully implement EPID-based invivo dosimetry.

Vladimir Feygelman

Vladimir Feygelman presented a review ofhistorical dosimetric QC methods,including film and ion chambers inphantoms, and a vision of the required

direction for the future, including methodsfor 3D and 4D dose reconstruction in thepatient. Regarding patient-specific QA, heenvisaged that the currently prevalentlimited comparison of dose distributions ina phantom by gamma analysis will beeventually replaced by clinically meaningfulpatient dose analyses with improvedsensitivity and specificity. In a larger sense,he envisaged ‘a future of QA built uponlessons from the rich history of “quality” asa science and philosophy’. This future willaim to improve quality (and ultimately

reduce cost) via advanced commissioningprocesses that succeed in detecting androoting out systematic errors upstream ofpatient treatment, thus reducing our relianceon, and the resource burden associated with,per-beam/per-plan inspection.

Alicia Cavan

Alicia Cavan (University of Canterbury,New Zealand, figure 2) provided one of anumber of presentations that discussedalternative novel or emerging dosimetrymethods, compared to established geldosimetry. Alicia discussed a novel opticalcalorimetry dosimetry approach and itsapplication with an HDR brachytherapysource. The technique of digital holographicinterferometry (DHI) was applied to themeasurement of radiation absorbed dosedistribution in water. An opticalinterferometer has been developed thatcaptures the small variations in the

refractive index of water due to theradiation-induced temperature increaseΔT. The absorbed dose D is thendetermined with high temporal andspatial resolution using the calorimetricrelation D = cΔT (where c is the specificheat capacity of water). The method iscapable of time resolving 3D spatialcalorimetry.

Simon Doran

Simon Doran (figure 3) provided ateaching review of optical CT techniquesapplied to Presage 3D dosimetry. Theworkflow for optical CT scanningincluding sample positioning, refractiveindex matching, the importance ofapparatus cleanliness to the imagingprocess, the pre-scan and imagereconstruction and post-processing wereall described for successful dosimetry.Unfortunately, optical CT is not entirely a‘push button’ technology process,although manufacturers and groupsworking in the field are moving steadilytowards this position.

Tomas Kron

Tomas Kron provided a discussion of thedosimetry challenges and requirementsfor audit and clinical trials. The increasingcomplexity of radiotherapy planning anddelivery makes audits challenging. Whileverification of absolute dose delivered at areference point was the standard ofexternal dosimetry audits two decadesago, this is often deemed inadequate forverification of treatment approaches suchas IMRT and VMAT. As such, mostdosimetry audit networks havesuccessfully introduced more complextests of dose delivery usinganthropomorphic phantoms that can beimaged, planned and treated as a patient

FIGURE 1. David Thwaites, conferencescientific organiser, animated in his review ofthe required and achievable accuracy inradiation therapy

FIGURE 2. Alicia Caven, adding particularinterest to the meeting with her novelresearch work on optical calorimetrydosimetry applied to HDR brachytherapy

The increasingcomplexity of radiotherapy

planning makes auditschallending“

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would. The new challenge is to adapt thisapproach to ever more diversifiedradiotherapy procedures with imageguided/adaptive radiotherapy, motionmanagement and brachytherapy being thefocus of current research.

Benjamin Nelms

Benjamin Nelms (University ofWisconsin), USA), presented by VladimirFeygelman, highlighted some ‘real-world’examples of sensitivity failures of the 3 percent/3 mm pass rate metric and publishedaction levels when used in IMRT/VMATsystem commissioning. It was proposedthat these examples of observed ‘falsenegatives’ (insensitivities) point towardsthe inappropriateness of the 3 per cent/3mm gamma passing rate metric as thebasis for acceptance testing/commissioning of the IMRT/VMATdelivery chain.

Debates and discussions

There were a number of valuable debatesessions and discussions throughout theconference. One topic of debate was thelack of conversion of gel-based dosimetryinto routine clinical practice over the last10 years. There had certainly been amisguided view from the early days that3D dosimetry would be required for everypatient, but the current view seemed to bethat the use of gels was still consideredvaluable for evaluation of new processesor techniques in radiotherapy centres. Gelsand plastic dosimeters are indeedcurrently the only dosimeters that can fullymeasure a full 3D dose distribution. Whilesome thought the challenge of using geldosimeters was no more complex thanother systems currently in routine use,several thought a huge effort was requiredfor their set-up in individual clinics and

that they are not practical except inestablished research departments. Oneparticular problem with the use of gels isthat they can only report integrated totaldose of a treatment. Advanced treatmentshave a dynamic component and in orderto track where errors may originate,temporal information on dose depositionis required. One particular advantage ofgels is that they can be used withinanthropomorphic phantoms and takenthrough the entire treatment chain.

It was proposed that it is notuncommon for people to be using 2D or3D dosimetry tools and analysis methodswithout fully understanding the systems.One good example was in the applicationof gamma analysis and its widespreadadoption in commercial systems. The‘good feeling’ given by simplistic gammapassing rates has been accepted andperhaps led to its overuse, rather than afull investigation and evaluation of theclinical impacts of any dose differencesbetween prescribed and delivered dosedistributions.

The value of 2D compared to 3D dosedistribution analysis, and the use of 2Dand 3D gamma, were discussed. Therewere differences of opinion on whether 2Dhas a place or whether dosimetry shouldnow be performed in 3D; the latter iscertainly the dose actually delivered to thepatient, but evidence of errors in 2Ddistributions being ‘averaged out’ in 3Danalysis was presented.

The future of 3D dosimetry was ofcourse discussed at various points in theconference. Although a completeconsensus of opinion may not have beenreached, all seemed to agree that thefuture of patient-specific QC for complexradiotherapy ideally lay in in vivodosimetry measurement.

On the question of what is the ‘best’dosimeter to use to assess the accuracy oftreatment dose delivery, the conclusionwas that all of the dosimetry systemsdiscussed are likely to have a place forspecific measurement situations, and noone dosimetry system would be optimumfor all cases. The question of whether 2D(semi-3D) or 3D dosimetry is preferablewas thought to be in some ways irrelevantor impossible to answer, since each systemshould be used when required for aparticular measurement situation. It was,however, clear that if you are only using2D measurement techniques and onlylooking at 2D gamma passing rates thenyour assessment is probably insufficient.

It was thought that a useful model maybe regional groups of centres in whichindividual departments have expertise inparticular measurement systems, andthese being used within the region forparticular measurements as may benecessary. The particular measurementsystem used should be matched to theinformation required, not just to themethod that is available within the centre,and with full understanding of thelimitations and any calculation algorithmsused. When asked which the ‘best’detector is, I (figure 4) believe that BenMijnheer summed up the feeling of theconference by stating: ‘the best thing touse is your brain’.

Summary

In a closing discussion, the following keyareas for further development andresearch were identified: analysis toolsand actual use of 3D measured dosimetrydata, increased development of in vivodosimetry, improved methods tocommunicate dosimetry data analysis toclinicians, commencement of widespreadadaptive treatments and proper use ofimage guidance and the impacts thesehave on dosimetric QC assessments,methods for validation of adaptive doseregistration, and improved decisionmaking on dosimetry detectors andanalysis metrics being used. n

FIGURE 3. Simon Doran drawing on hisextensive experience of Presage geldosimetry

FIGURE 4. Tony Palmer enjoying a climb overSydney Harbour Bridge after presentingresearch on Gafchromic film dosimetry atthe conference

‘ MORE INFORMATIONThe next meeting is planned for August 2014, to beheld at Lund University, Sweden.

Conference photos reproduced courtesy of MayWhitaker. The conference was sponsored by Elekta,ScandiDos, Varian, New South Wales GovernmentDepartment of Health, The University of SydneyInstitute of Medical Physics, Macquarie University,CMSAlphatech, Sun Nuclear Corporation,Nucletron, University of Wollongong, ni-tec,Medtech and the Australian College of PhysicalScientists and Engineers in Medicine (ACPSEM).

MEETING REPORTS


PEM was fully booked several weeks infor the IMRT verification meeting.Twenty-two abstracts had been submitted

and all were to be presented either as talksor posters. Four manufacturers weredisplaying their varied equipment and IMRTverification was foremost in everyone’sminds, particularly as the RadiotherapyInnovation Fund had recently beenannounced to help expand the numberstreated with IMRT.

The meeting opened with Ran Mackay(Christie Hospital, Manchester) setting thescene with the arguments both for andagainst IMRT verification measurements. Heused an analogy with the airline industry toconsider what pre-treatment (pre-flight)checks do and don’t help us find. Theconclusion was that by asking ‘to do or notto do’ we are asking the wrong question. Thepre-treatment measurement is a good checkof plan transfer, but will not catch all errorsand that there are other ways to verify IMRTplans, not all of which need to bemeasurement based.

The next talk was by Catharine Clark(Royal Surrey Hospital, Guildford) and gavethe survey results of the current status of

IMRT verification in the UK (figure 1). Thesurvey had been carried out in of 2012 andhad responses from 53 UK centres. The datashowed that all centres were makingmeasurement-based verifications of someform and that two-thirds were also usingsoftware-based methods. The majority areplanning to change their QA processes in thenear future, with the changes being mainlyin the numbers and types of measurements,but also in who was carrying them out.

Further talks followed from two centreswho have been delivering IMRT for over adecade and focussed on how they hadexpanded their service without limiting thenumbers (Carl Rowbottom, ChristieHospital, Manchester) and the problems andpitfalls they had encountered in decidinghow to reduce measurements (CaroleMeehan, Royal Marsden Hospital). Carl had

taken the approach that systems of servicedelivery can have general similarities andquoted from the theory used by EdwardsDeming in his book Out of the Crisis to lookat the future of IMRT QA and work outprocesses that identify the errors which mayhave the greatest effects without too much ofa time burden. Carole gave an overview of adecade of IMRT delivery at RMH and thedecisions which had been taken along theway to reduce IMRT verificationmeasurements. She gave examples from thevery early days when IMRT verificationmeasurements and analysis could take up to8 hours per patient, through to the morerecent use of portal dosimetry which can bedone in a few minutes.

The next session was ‘What are we reallylooking at and what does it mean?’.Mohammad Hussein (Royal Surrey CountyHospital, Guildford) began by looking atfive different verification systems (includingthree arrays) and testing them withpurposeful errors introduced into clinicalplans. He had used the gamma analysistechnique for each system and it wasinteresting to see that not all systemscalculated in the same way. Geoff Budgell

I

FIGURE 1. IMRT verification survey data for reasons why software-based calculations can be out of tolerance

The conclusion wasthat by asking ‘to do or not

to do’ we are asking thewrong question“

“

IMRT VERIFICATION MEETING:MAKING THE MOST OF ITCATHARINE CLARK Royal Surrey County Hospital and National Physical Laboratory

ROYAL GEOLOGICALSOCIETY, LONDON23rd November2012 ‘

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(Christie Hospital, Manchester) thenexplained the pitfalls of using the gammaanalysis technique, with a warning on takingcare over how the plan is normalised,whether you use global or local gammacalculations, which regions of interest to lookat and how the calculated and measuredplans are aligned. His take-home messagewas to be consistent and not to simplytransfer tolerances and passing criteriabetween different systems and techniques.Antony Carver (Clatterbridge Cancer Centre,Liverpool) then showed us what errors inIMRT plans might really mean in terms ofclinical impact. He warned that even somesmall dose differences may result inunwanted TCP changes and recommendedthat a specific mean dose deviation should beapplied to limit TCP changes in the event ofa dose delivery error.

Lunch was held in the GeologicalSociety’s library, where posters were viewed,opinions were sought, manufacturers werevisited and beautiful maps of the rock strataof the British Isles were gazed at.

We then focussed our attention on thequestion ‘Can EPID solve all our problems?’.

Bas Nijsten (Maastro Clinic, TheNetherlands) opened the session, giving usan insight as to what the future might hold.This group has been working on EPID(electronic portal imaging device) dosimetryfor several years now and Bas gave anexciting glimpse of the kind of verificationmeasurements we may use in the future, inparticular the ability to backproject themeasured beam fluence onto the CBCT ofthe day to create a ‘3D dosimetry of the day’.This opening talk was followed by threeproffered papers from Barts and UCL on thedevelopments they have made themselves inthis area, showing that we are making goodprogress in the UK in this area too. There isno doubt that EPID will solve at least someof our problems.

The final session of the day was ‘Could asoftware solution be the answer?’. Thissession had six proffered papers from sixdifferent departments, discussing both in-house and commercial solutions. AndrewWilliams (Norfolk and Norwich Hospital,Norwich) opened with a presentation onhow they had managed to remove thephysics bottleneck by using the software to

mimic the point dose measurements from anarray, allowing linac-based QA to be phasedout. Christina Agnew (Northern IrelandCancer Centre, Belfast) presented her workon the use of dynalog files from Varianmachines to verify treatment plan delivery aswell as assess the relationship betweenmachine performance and plan complexity.All the speakers stressed the time differencerequired between software approachescompared with measurement-basedapproaches, with a clear direction for thefuture that software-based verification willallow a greater number of IMRT plans topass through the physics department.

The day ended with a discussion. As allcentres were considering their requirementsfor expanding IMRT with the opportunitiesafforded by the Radiotherapy InnovationFund, this discussion was extensive andmany wanted recommendations as to thebest way forward. As ever the opinions wereas varied as the products and the discussioncontinued to the very end of the session.

We would like to thank all the invited andproffered speakers and poster presenters fora very interesting and useful day! n

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QA software for advanced RT

ImSimQA ™™

OSL-Mkt-ImSim-SCOPE-v1

Atlas-based auto-contouring, deformable image

registration, and adaptive RT are growing fast. How do you use hard phantoms to test these

systems? Answer: You can’t.

ImSimQA is an essential software toolkit that

generates DICOM test images to validate clinical

software systems, and then runs quantitative

analyses to measure results.

DICOM image data can be created from a library of

phantoms and importing images of any DICOM-3

modality is possible. Images can be transformed,

deformed, contrast enhanced, mainpulated by

filters (e.g. CBCT or MVCT) and DICOM edited to

create an infinite range of test data.


he RSNA annual meeting is the largestmedical meeting in the world,attracting approximately 60,000

attendees each year. It is held at McCormickPlace, Chicago (figures 1 and 2), which justa few weeks before the 2012 annual meetinghad hosted President Obama’s electionnight party. The meeting focuses on allaspects of medical imaging and there was awide range of educational and scientificsessions on offer, from formal researchpresentations to educational exhibits andinteractive workshops.

Updating knowledge

Having only previously attended muchsmaller conferences in the UK I wasimmediately awestruck by the scale of theevent. Just walking from one end of thecavernous McCormick Place to the othertook upwards of 15 minutes. The‘programme in brief’, which named all thesessions at the conference, ran to over 400pages! However, despite the potentialdifficulties in running such a hugeoperation most aspects of the meetingseemed well thought-out and wellorganised; from the constant stream of

coaches ferrying people across the city viathe reserved bus lanes to the use ofdedicated smartphone applications todirect delegates to their chosen sessions.

I have recently become involved withthe Sheffield 3D Imaging Lab, which aimsto accelerate the uptake of advanced 3Dvisualisation and quantitative imagingtechniques. Coming from a pure nuclearmedicine background I was keen to updatemy knowledge on quantitative imaging inthe other modalities. I therefore chose tofocus much of my attention on the‘refresher sessions’, which presented up-to-date reviews of certain areas within medicalimaging. One such session of particularinterest was entitled ‘Techniques forquantitative cancer imaging: current status’.The speakers gave an overview of currentquantitative measurement techniques used

in MRI, CT and PET and then went on todiscuss the various benefits and issuesassociated with them. The main messagethat came across was that there is inherentvariability in all modalities and althoughthey can be very useful, quantitativemeasures should always be treatedcarefully. Binsheng Zhao (ColumbiaUniversity Medical Center), for example,detailed all the factors that can influencetest-retest variability in CT scans andhighlighted data suggesting that repeatscanning of the same patient on the sameCT scanner, just 15 minutes later, can leadto differences in linear tumourmeasurements of greater than 17 per cent.He therefore suggested that small changesin apparent tumour diameter may not besignificant. Focusing on dynamic contrastenhanced MRI Gregory Karczmar(University of Chicago, USA) suggestedthat, at best, a reproducibility uncertaintyof 10 per cent is possible for measurementsof apparent diffusion coefficient (ADC).The final talk of the session, focussing onPET and standardised uptake value (SUV)measurements, was given by Paul Kinahan(University of Washington, USA). He

T

FIGURE 1. Central hallway at McCormick Place FIGURE 2. View of downtown Chicago from McCormick Place

The RSNA annualmeeting is the largestmedical meeting in the

world“

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RADIOLOGICAL SOCIETY OF NORTHAMERICA (RSNA) ANNUAL MEETINGJONATHAN TAYLOR Sheffield Teaching Hospitals NHS Foundation Trust

MCCORMICKPLACE, CHICAGO25th–30thNovember 2012‘

MEETING REPORTS


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FIGURE 3. Digital refence object with pre-defined regions of interest

FIGURE 4. Summary of results from the SUV measurement study

MEETING REPORTS


highlighted an important issue foranyone involved in providing a PETservice – that there is often a tensionbetween the needs of clinical protocols andresearch protocols. Clinical PET usuallyrelies on visual interpretation and thusmost PET scanners and PET protocols areset up with this in mind. However,research studies are often far more relianton quantitative information, which mayrequire more stringent administrationprotocols and camera quality assurance.

Quantitative measuring

One of the stated commitments of RSNA isto make radiology a more quantitativescience. Thus, the Quantitative ImagingBiomarkers Alliance (QIBA) wasestablished in 2007 to take forward thisaim. During the annual meeting I attendeda number of presentations and educationalexhibits detailing the work of QIBA. Muchof this was directly relevant to theSheffield 3D Imaging Lab but also toanyone involved in taking quantitativemeasurements from medical images. Oneproject with somewhat surprising resultsinvolved generating a digital referenceobject (i.e. an electronic phantom) withdimensions matching that of the standardNEMA PET image quality phantom. Theimage data was sent to 13 different siteswith each asked to measure maximum,minimum and standard deviation SUVvalues for six pre-defined regions-of-interest (figure 3). The results receivedback were far from uniform (figure 4),suggesting that there may be variability in

how SUV calculations are performed bydifferent centres/systems.

Another interesting presentationrelated to the QIBA initiative was given byNicholas Petrick (US Food and DrugAdministration (FDA), Washington, DC,USA). Using results from a number ofstudies of realistic anthropomorphicphantoms he set out to explain the impactof different factors on the accuracy andprecision of CT measures of tumour size.The type and location of the tumournodule proved to have a substantialimpact on results – spherical or lobularnodules in the centre of the lung, forexample, were measured fairly accuratelywith 1D, 2D and semi-automated 3Dmeasures. However, more complicated,‘spliculated’ nodules produced muchgreater measurement errors, particularlywhen located next to pleural tissue andwhen using 1D and 2D measures. It wasalso highlighted that CT parameters, inparticular slice thickness, can have adramatic impact on quantitative measuresof tumour size.

In addition to the refresher talks I alsoattended a number of ‘informatics’sessions, many of which were dedicated toopen-source image analysis software. Asbecame apparent there are several open-source packages available, some of whichhave been developed over many years andhave become extremely sophisticated.Such software could be of great benefit toany centres carrying out imaging research,particularly when the money available forbuying expensive program licenses is so

restricted. It was therefore very useful tobe given a hands-on introduction tovarious platforms, including 3D Slicer,ImageJ and MRI Studio by the originaldevelopers of the code.

The RSNA annual meeting offersseveral different ways for researchers topresent their work. Having submitted anabstract I was asked to produce an‘informal scientific (poster) presentation’,which was an entirely new concept to me!As I later discovered such presentationsare displayed on one of many TV screensfor delegates to browse through at theirleisure. An allotted time is then set asidefor the author to discuss the research andanswer any questions. Although mypresentation was based on a specialistand very specific area in medical imaging– automatic tumour tracking using imageregistration – I was pleased to find atleast a few people turned up to askquestions!

Social events

An unexpected benefit of having anabstract accepted by RSNA was that I wasinvited to a reception at the residence ofthe British Consul General. Afterchecking that they had invited the rightperson I duly accepted the offer knowingthat such an opportunity was unlikely topresent itself again any time soon. TheConsul’s residence turned out to be avery grand apartment on the 62nd floorof a building in downtown Chicago. Withfloor-to-ceiling glass panels spanning twolevels, the apartment offered amazingviews of the city, which were made all themore pleasurable by the champagne andcanapés that were continually put in frontof me. I’m not sure how much good I didfor British industry but I would gladlycome and make up the numbers again!

After the conference I set aside a dayto explore Chicago further. Luckily theweather was unseasonably mild and dry.Other than the obligatory visit to theWillis Tower with its Skydeck (a glass boxattached to the 103rd floor offeringvertigo-inducing views) I was able to visitmost of the downtown parks, includingMillennium Park, which hosts the famousCloud Gate sculpture (figure 5).

Overall, my visit to the RSNA annualmeeting was thoroughly enjoyable andextremely useful, both for myself as arelative newcomer to quantitativeimaging and to the Sheffield 3D ImagingLab as a whole. I would like to thankIPEM for providing me with funding tomake this trip possible. n

FIGURE 5. Cloud Gate sculpture

‰

MEETING REPORTS


he 12th International Conference onElectronic Patient Imaging tookplace in Sydney from 12th to 14th

March 2012. The conference immediatelydrew my attention as it was highlyrelevant to my own area of research –using the EPID as a tool for in vivodosimetry. I thought this would be anexcellent opportunity to present my workat an international level and learn aboutother similar projects going on throughoutthe world. I was able to attend thisconference thanks to an IPEM bursary andsupport from the developers of thesoftware I had been working with, MathResolutions.

A stimulating and intense programmehad been planned, with invited lectures

from internationally renowned speakers,refresher courses, proffered papers,scientific sessions, poster sessions, vendorQ&A, tutorials and a research symposium.The conference was held at the Four PointsSheraton Hotel at Darling Harbour, a greatlocation to enjoy the lively city and lovelyharbour (figure 1).

Day 1

Each day of the conference had its owntheme: day 1 was ‘Real-time tumourlocalisation and adaptation in cancerradiotherapy’, day 2 was ‘Margins,adaptation, technology’ and day 3 was ‘In-room imaging, immobilisation, dosimetry’.The conference encompassed manydifferent verification imaging techniques

and the clinical applications of thismodern technology, such as IGRT, SBRTand motion management.

Day 1 kicked off with a warm welcomefrom conference convenor May Whitaker(University of Sydney, Australia),followed by a brief introduction to real-time tumour localisation and adaption inradiotherapy by symposium chair PaulKeall (University of Sydney, Australia).

One of the many interesting talks onthe first day was on multileaf collimatoradaptation by Uwe Oelfke (GermanCancer Research Center (DKFZ),Heidelberg, Germany). He described adynamic control system which enablesreal-time tracking of moving targetvolumes to improve delivery accuracy.

FIGURE 1. The iconic Sydney Opera House as seen from across Sydney Harbour

‰

T

12TH INTERNATIONAL CONFERENCE ONELECTRONIC PATIENT IMAGING (EPI2K12)LEILA NICHOL Royal Surrey County Hospital, Guildford

SYDNEY,AUSTRALIA12th–14th March2012 ‘

MEETING REPORTS


Through continuous optimisation usingMLC control and a verification loops, theaperture dynamically changes shape andsize during treatment; ‘breathing leaves’.The algorithms calculate new leafpositions based on target informationprovided online to the system, using MLClatency to predict the future position. Thenew tracking system has not yet been usedon patients, but preliminary results haveshown increased accuracy and quality oftreatment delivery. In a clinical situation,the target motion of each patient wouldhave to be assessed before the radiationdelivery.

Day 2

One of the highlights of day 2 was alecture on CBCT for intra-fractionmonitoring and adaptive RT by keynotespeaker Marcel van Herk (NetherlandsCancer Institute (NKI), Amsterdam, TheNetherlands). He began by emphasisingthe importance of appreciating andselecting the appropriate frequency forimaging; are we looking at weeklychanges, daily set-up errors, minute-by-minute before and after differences, or onthe scale of real time? IGRT is acompromise between speed and quality;2D bone/marker matching is a quick andsimple check, 3D soft tissue matching isoften more informative and appropriate,real-time 4D motion tracking involvescomplex reconstruction, and full adaptiveradiotherapy can involve taking accountof many days’ scans to adapt and deform

the treatment delivery accordingly. 2Dplanar imaging, although quickest, cannotdetect tumour shrinkage, weight loss,tumour positional changes, markermigration or normal tissue changes.Intrafraction imaging can provideinformation on respiratory motion,baseline tumour shifts, bladder filling,peristalsis and patient movement forwhich algorithms can be constructed orfilters applied, for example using theAmsterdam shroud technique. This wasall very useful food for thought.

Marcel went on to speak about a novelimaging solution being investigated atNKI: simultaneous CBCT and VMATdelivery. Ultimately a 4D validation scanis acquired during the VMAT treatmentdelivery arc, allowing GTV tumourmotion to be assessed with respect to thePTV margin. There are approximately1,000 projections per arc, correspondingto a CBCT dose of 1.5 cGy. Problems theyencountered using concurrent CBCT-VMAT included scatter from thetreatment beam, line artefacts on theCBCT due to accelerator pulses and theincreased noise. To overcome this, amicrocontroller was used to alternateimage acquisition to sync with acceleratorpulses. The images were filteredaccording to beam on/off acquisitionsand a derived scatter correction wasapplied. By examining the differentialmotion, an average patient model couldbe established to provide a model foradaptive RT.

Day 3

On day 3, Boyd McCurdy (University ofManitoba, Canada) gave an excellentrefresher on EPID-based patient doseverification. There are several challengesencountered when attempting to use theEPID as a dosimeter: modern a-Si panelsare not water equivalent and thereforedue to the metal and phosphor screen,the panels are more responsive to lowenergy x-rays; the EPID housinggenerates a self-scattering component;older camera-based systems had issueswith optical glare; there is non-uniformbackscatter due to the arm; the effect ofpatient scatter; ghosting and image lag;sag of the imager with gravity at non-zero gantry angles; incomplete signalacquisition during cine mode (63 msdelay), and difficulty preciselydetermining gantry angles (±3°). Many ofthese effects can and have been modelledby various groups around the world inorder to successfully calculate absolutedose via simulated back projection. Usingthe EPID in this way enables dosecalculations using the ‘exit’ radiationimages acquired during the patienttreatment to pick up detectable errors,including machine (wedge, missingsegments, MLC, leaf sequences,collimator angle, beam flatness/symmetry, output), plan (transmissionthrough leaves, gradients, MLCmodelling, plan transfer) and patient(table, immobilisation, anatomicalmovement and changes, wrong patient!)

FIGURE 2. Example of isodose overlay of a RapidArc plan usingDosimetry Check (blue is TPS and green is DC)

FIGURE 3. Mean dose to primary PTV differences between DosimetryCheck and TPS for pre-treatment and transit results

‰

MEETING REPORTS


errors. Several errors have been caughtand documented using this method,differences mainly due to anatomicalchanges, and in one case, a discovery thatincorrect tongue and groove parametershad been entered into the TPS.

David Thwaites (University of Sydney,Australia) then gave an overview of aselection of products available forperforming on-board in vivo dosimetry.This is evidently a market that is rapidlydeveloping, with increasing worldwidepressure for a solution for patient dosecheck. Following on from this was afascinating series of proferred papers onthe topic of novel in vivo dosimetry andapproaches. These included: BoydMcCurdy expanding upon his earliersession by describing an accurate methodfor patient dose reconstruction from on-treatment EPID images; Brad Oborn(University of Wollongong, Australia) ona Geant4 Monte Carlo simulation methodfor IMRT verification; Lei Xing (StanfordUniversity, California, USA) on directmeasurement of leaf positions with EPIDfor verification of IMRT segments, and

Tanya Kairn (Queensland University ofTechnology, Brisbane, Australia) on in vivoEPID dosimetry in head and neck cases: asimple technique using the TPS to predictdose at the EPID plane.

My e-poster presentation

My own e-poster presentation was alonga similar theme: ‘In vivo dosimetry using“Dosimetry Check” – a commercial EPID-based transit dosimetry solution’. Theconcept of an e-poster was new to me butworked well, with a laptop workstationsection set up in the exhibition hall,allowing delegates the freedom to perusethe posters at their leisure. There was a lotof interest in my poster and I gave severaldetailed presentations to individuals andsmall groups. Having been involved inthe initial beta testing of the in vivomodule of the dosimetry check systemand commissioning it over two differentsites (Edinburgh Cancer Centre and RoyalSurrey County Hospital), I was able topresent a thorough overview of thesystem and my latest patient results. Ibriefly explained the rationale behind

performing in vivo dosimetry (withspecific reference to Towards SaferRadiotherapy), the advantages of using theEPID over conventional methods, thecommissioning process, the clinicalpathway and the calculation model. Ipresented an example VMAT patient casestudy and the overall results over 47 IMRTand VMAT patients indicating that thesystem was calculating the mean dose tothe primary PTV to within 0.5 per cent(±2.3 per cent) compared with the TPS(figures 2 and 3). Using the EPID toperform in vivo dose calculations in thisway simulates the full clinical situationand provides the final verification of thedose being received by the patient.

The conference was an intense,informative and educational meeting witha stellar cast of speakers and was aninvaluable experience for me, thanks tothe IPEM bursary. The next EPI conferencewill be held in Aarhus, Denmark, in 2014and I thoroughly recommend this toanyone interested in verification imagingin the radiotherapy community, as thiswas a truly excellent conference. n

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MEETING REPORTS


elcome to the second2013 issue of ‘BookReviews’. There arethree textbook reviews inthis issue covering the

medical physics genre. A list of thereviewed titles with reviewers can befound in table 1.

As with each Scope issue, there are anumber of new medical physicstextbooks in the ‘Just Published’ sectionsuch as 4D Modelling and Estimation ofRespiratory Motion for RadiationTherapy, which illustrates registrationand motion algorithms for theinterpretation of complex 4D medicalimage sequences, and InterstitialProstate Brachytherapy, which providesa comprehensive overview of innovationsin LDR, HDR and PDR interstitialbrachytherapy for the management oflocal or locally advanced prostate cancer.You will find some interesting reportslisted in the ‘New Reports’ section, suchas ‘Practical Guidance on ThyroidMonitoring for Radioiodine Using Hand-held Instruments’.

Readers interested in reviewinglisted/unlisted books should get in touchwith me, so I can arrange to send you therequired material directly from thepublisher. Note that some of the newreports are freely available to download(as PDFs) from the respective websites.

Urgent request for reviewers

We really do require more bookreviewers to maintain a steady stream ofreviews for Scope. Please drop me anemail if you are interested in becoming areviewer.

Apart from the numerous benefits ofreviewing, it can also count towards yourCPD which is a requirement for thoseregistered with the HCPC.

Usman I. Lula is a Principal ClinicalScientist based in the RadiotherapyPlanning section (Radiotherapy PhysicsQEMC) at the Queen Elizabeth Hospital,University Hospitals Birmingham NHSFoundation Trust, UK.

Email: [email protected]

BOOK REVIEWS

INTRO

WWebb’s Physics ofMedical Imaging

There has beena very long waitfor the secondedition of thisbook, whichwas firstpublished in1988. There is anew editor, butthe consistent

editing approach of the original isretained, leading to a cohesivetextbook, in spite of the 25contributors. An attraction of thisbook, compared with others thathave a similar coverage, is that thematerial was originally aimed atpostgraduate engineers andphysicists rather than at radiologists.So, there is a rigorous approach tomathematics throughout, imageprocessing and the mathematics ofimage formation are includedexplicitly, and for some modalitiesthere is a physics-eye view of qualityassurance and phantoms. For thistarget readership some basicknowledge is assumed – readerswithout, for example, a degree inphysics may need supplementarymaterial to bring them up to speed.

The editor’s aim was to keep thecontents in one, manageable bookwhile retaining accessibility forstudent use. Overall, in spite of themany new developments to beincluded, the challenge has been met.Chapters on the main imagingmodalities have been overhauled,with the almost historical-lookingimages of the first edition replacedwith up-to-date examples. Chapterson infrared and electrical impedanceimaging have been retained, thediaphanography chapter has been

replaced by one on optical imagingand the medical image processingcontent has been extended. There is alot covered and the index is, perhapssensibly, not comprehensive. Thecontents listings at the start of eachchapter are more useful. The finalchapter makes interesting reading asit encourages readers to step out frommodality ‘silos’ to compare andcontrast imaging modalities and theirapplications. Legislation andregulatory issues are not covered.

Although the content has beenupdated, the book has a very similarappearance to the 1988 version, withsingle column text and interspersedillustrations. It follows an old-styletextbook approach: there are no boxeshighlighting points of interest, noworked examples and no colourenhancements to greyscale diagrams.There are no questions or exercises forthe reader. One addition is theinclusion of colour illustrations; theseare grouped together in sets of colourplates. The book has a scholarly feel –the lists of references at the end ofeach chapter are longer than would beexpected in a textbook. These neednot be consulted immediately, butthey future-proof the purchase as theymay turn out to be valuable later inthe reader’s career.

A Kindle version is available – itcan be read using apps and tablets butnot with a basic Kindle device. I trieda sample using the PC app. Thebook’s pages are reproduced, they canbe zoomed and you can add notes.However, the app does not allow thetext to be searched, which would havebeen a valuable feature.

This book is excellent value formoney and is a strong contender as atextbook for masters level courses.Buy one early on, and this is a bookthat you’ll consult throughout yourcareer.

TABLE 1Book title Reviewer

n Webb’s Physics of Medical Imagingn Monte Carlo Calculations in Nuclear Medicinen Digital Mammography: A Practical Approach

Elizabeth BerryDavid HallLisa Davenport


Reviews of textbooks recently published onmedical physics, and details of newly

published books and reports

WEBB’S PHYSICS OF MEDICAL IMAGING(2ND EDITION) M. A. FLOWER (editor)Publisher: CRC PressISBN: 978-0-7503-0573-0Format: HardbackPages: 864

MONTE CARLO CALCULATIONS INNUCLEAR MEDICINE – APPLICATIONS INDIAGNOSTIC IMAGING (2ND EDITION)MICHAEL LJUNGBERG, SVEN-ERICSTRAND, MICHAEL A. KING (editors)Publisher: CRC Press, Taylor and FrancisGroup, Boca Raton, London and New YorkISBN: 978-1-43-984109-9Format: HardbackPages: 357Price (publisher's website): £82

DigitalMammography: APractical Approach

Perhaps you areemerging,bleary eyed andstaggeringslightly, into abright newdawn followingall your digitalmammographycommissioning.

Maybe you have yet to stumble into thewhirlwind. Or maybe you can flythrough your routine tests withoutchecking the work instructions every 3seconds. Wherever you are in yourdigital mammography journey, if youhave time to pause and reflect, you willlove this book.

I haven’t checked if there arecomparable books out there but thisone is pretty much perfect. It isbeautiful and glossy and feelsexpensive (that’ll be because it isexpensive…).

The book is a compendium ofchapters by American physicists andradiologists. Chapters are presented inscientific paper format with discussionand references at the end of each. Acouple of the chapters repeat whatothers have said but in the main theycome together to provide a very

Monte CarloCalculations inNuclear Medicine

The first editionof this book,published in1998, was one ofthe first todescribeapplications ofMonte Carlomethods innuclear medicine,

and 15 years on this largely changed,or rewritten, second edition describesmajor changes in programs andmethods, though the editors stillrecommend having both editions!

The book contains five backgroundchapters, six on specific Monte Carlocodes, two on scatter correction inSPECT and PET, and three onapplications. It is not toomathematical, but is fairly dense andrewards close reading.

The background chapters, onMonte Carlo methods, variancereduction techniques,anthropomorphic phantoms, andgamma camera and PET basics, areclear and well referenced, with areassuch as Bremsstrahlung imaging andsolid state detectors added since thefirst edition. Variance reductiontechniques – the methods andapproximations used to deal with theinefficiency of PET and SPECT – arewell covered, and these methods arereferred to extensively in laterchapters. Developments inanthropomorphic phantoms are also

particularly well described throughoutthe text.

The chapters on Monte Carlo codeswhich follow are the heart of the book.The methods covered – two generalpurpose high-energy physics codesEGS and MCNP, SIMIND for SPECT,SimSET and GATE for SPECT andPET, and the analytic PET simulatorASIM – are described by some of thelead developers and users. In all casesa wealth of information is providedwhich would allow any interesteduser to decide between the codes, andthe chapters are up-to-date andcomplete. There are some differencesin terminology, for exampleimportance sampling instead ofvariance reduction in one chapter, andsome differences in coverage, but allmethods are well referenced and havemore information available online.

The book closes with chapters onscatter correction, which should be ofgeneral interest to nuclear medicineprofessionals and applications in thedesign of molecular imaging systems,image quality assessment and nuclearmedicine dosimetry. The chapters onsystem design and image qualitywould be very useful in developingresearch protocols. The chapter onnuclear medicine dosimetry is clear,but is unfortunately limited to theauthor’s own work.

My main criticism of the book is thelack of a review chapter coveringMonte Carlo modelling in nuclearmedicine, or any comparisons ofaccuracy or speed of calculation, ordifficulty of implementation. Thismakes the book less useful as anintroductory text. However, I foundthis a clear and inspiring book and Iwould recommend it to departmentsor individuals interested in any ofthese methods.

Dr David Hall is Head of the NuclearMedicine Physics Section, Departmentof Medical Physics and Bioengineering,University Hospitals Bristol NHSFoundation Trust, and is based at theNuclear Medicine ImagingDepartment, Bristol Royal Infirmary,Bristol, UK

‰

Dr Elizabeth Berry is the Director ofElizabeth Berry Ltd (Berwickshire) andspecialises in medical imaging. She tutorsfor the Open University and is a Fellow ofboth IPEM and IoP

The chapters onsystem design and

image quality would bevery useful in

developing researchprotocols

“ “


BOOK REVIEWS

comprehensive and (as the subtitlesays) practical view of digitalmammography.

After an introductory paragraph orso we go straight into the image qualitymetrics section. This is ideal forrefreshing your mind on MTF and whatthat CDMAM phantom is actuallydoing. However, beyond the traditionalphysics bits on detectors, imageprocessing and quantitative imagetesting, I found this book to beespecially useful for seeing the broaderpicture; the bits that medical physicistsdon’t get to see so much. This includesthe presentation and radiologists’interpretations of images, PACS (usefulstuff applicable to all modalities),efficacy of digital breast screening,artefacts, a lengthy and well-illustratedchapter on clinical cases, and a chapteron procedures such as stereo breastbiopsy. There are also the expectedchapters on developments intomosynthesis and breast CT.

Being an American book, all theregulations and guidance referred to areAmerican and the issues regardingavailability of breast screening to thepopulation are different to in the UK,but I didn’t find this a hindrance to thebook’s usefulness. I would definitelyrecommend this book to anyone whonot only wants clear explanations ofdigital mammography technology butalso a broader understanding of all thepractical issues.

If, like me, you have a tendency tomoan about having to drive for an hourthrough the snow to a remote, boilinghot caravan, not daring to fiddle withthe air-con for fear of breaking themammo set, this book may help yousee the error of your ways.

Lisa Davenport is a Clinical Scientistspecialising in Radiation Protection andis based at the Radiation Physics sectionof Bradford Teaching Hospitals NHSFoundation Trust, Bradford (UK)

DIGITAL MAMMOGRAPHY: A PRACTICALAPPROACHGARY J. WHITMAN, TAMARA MINERHAYGOOD Publisher: Cambridge University PressISBN: 978-0-521-76372-1Format: HardbackPages: 192Price: £65 (US$99)

‰ act as a reference and self-study guidefor more specialised in-depth studies.

The History of Radiology by AdrianM. K. Thomas and Arpan K. Banerjee(OUP) is a beautifully illustratedreview of the remarkabledevelopments within radiology andthe scientists and pioneers who wereinvolved. The engaging andauthoritative history will appeal to awide audience including medicalstudents, medical physicists, medicalhistorians and radiographers.

Interstitial Prostate Brachytherapy byGyorgy Kovacs and Peter Hoskin(Springer) is the first interdisciplinarybook on the subject providing acomprehensive overview ofinnovations in LDR, HDR and PDRinterstitial brachytherapy for themanagement of local or locallyadvanced prostate cancer. All chaptershave been written by internationallyrecognised experts who for more thana decade have formed the teachingstaff responsible for the successfulGEC-ESTRO/EAU prostatebrachytherapy teaching course.

4D Modelling and Estimation ofRespiratory Motion for RadiationTherapy by Jan Ehrhardt and CristianLorenz (Springer) illustratesregistration and motion algorithms forthe interpretation of complex 4Dmedical image sequences. Different 4DCT image acquisition techniques andconceptually different motionestimation algorithms are presented.This book is aimed at biomedicalengineers, medical physicists,researchers and physicians working inthe fields of medical image analysis,radiology and radiation therapy.

Quantifying Morphology andPhysiology of the Human Body usingMRI by L. Tugan Muftuler (Taylor &Francis) reviews various MRItechniques for obtaining quantitativeand physiological information on thehuman body. It compares andcontrasts several different applicationsof MR in quantitative researchincluding data acquisition, processingand analysis/ interpretation.

Just Published!Introduction to Nuclear Science, 2ndedition by Jeff C. Bryan (Taylor &Francis) provides an introduction tonuclear chemistry and physics, frombasic concepts to nuclear power andmedical applications. There are newchapters which cover nuclear reactortypes, their safety systems and recentaccidents such as the one inFukushima, Japan. This book is aimedat those studying nuclear medicineand radiation therapy.

Physics-based Deformable Modelsby Dimitris N. Metaxas (Springer)presents a systematic physics-basedframework for modelling rigid,articulated and deformable objects,their interaction with the physicalworld and the estimate of their shapeand motion from visual data. Itpresents a large variety of methodsand associated experiments incomputer vision, graphics andmedical imaging and is suitable forstudents in medical imaging andbiomedical engineering.

Exciting Interdisciplinary Physics byWalter Greiner (Springer) provides amajor focus on nuclear structurephysics, quantum electrodynamics ofstrong fields. It covers areas thatinclude high-energy physics,astrophysics and medical physics(heavy ion tumour therapy).

Medical Imaging Technology by MarkA. Haidekker (Springer) provides anintroduction into the principles ofimage formation of key medicalimaging modalities. This includes CT,MRI, ultrasound and radionuclideimaging. This textbook is aimed atbiomedical imaging students and can

There are newchapters which covernuclear reactor types,

their safety systems andrecent accidents such

as the one inFukushima, Japan

“ “


Reviews of textbooks recently published onmedical physics, and details of newly

published books and reports

Vulnerabilities in ProgrammingLanguages through Language Selectionand Use. ISO/IEC/TR 24772 ed2.0; March2013.

n Radiation Protection Instrumentation:Measurement of Discrete Radionuclidesin the Environment – In Situ PhotonSpectrometry System Using aGermanium Detector. Project IEC 61275ed2.0; March 2013.

n Amendment 1 – Ultrasonics –Hydrophones – Part 3: Properties ofHydrophones for Ultrasonic Fields up to40 MHz. Project IEC 62127-3-am1 ed1.0;March 2013.

n Ultrasonics: Physiotherapy Systems –Field Specifications and Methods ofMeasurement in the Frequency Range0.5 MHz to 5 MHz. IEC 61689 ed3.0;February 2013.

n Medical Electrical Equipment – Part2-11: Particular Requirements for theBasic Safety and Essential Performanceof Gamma Beam Therapy Equipment.IEC 60601-2-11 ed3.0; January 2013.

NEW REPORTSn Guidance on the Management and

Governance of Additional RadiotherapyCapacity – A Joint Publication of IPEM,RCR and SCoR. The Royal College ofRadiologists; March 2013.

n Radiation Protection in PaediatricRadiology. IAEA Safety Reports Series,STI/PUB/1543; 2013.

n Non-HEU Production Technologies forMo-99 and Tc-99m. IAEA Nuclear EnergySeries, STI/PUB/1589; 2013.

n Neutron Generators for AnalyticalPurposes. IAEA Radiation TechnologyReports, Number 1, STI/PUB/1535;2012.

n Human Radiosensitivity. HPA RCE 21;March 2013.

n Practical Guidance on ThyroidMonitoring for Radioiodine Using Hand-held Instruments. HPA-CRCE-044;February 2013.

n Trends in Dental RadiographyEquipment and Patient Dose in the UKand Republic of Ireland – A Review ofData Collected by the HPA Dental X-Ray

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n Full Quarterly Radiotherapy Error DataAnalysis for Periods August 2011 to July2012. HPA Update, Issue 7; January 2013.

n IVD and Patient Safety Considerations.Presentation at BIR; December 2012.

n Learning from Errors – The NationalPicture. Presentation at BIR; September2012.

n Radiation Dosimetry and Image QualityAssessment in Computed Tomography.ICRU Report Number 87, Volume 12,Number 1; 2013.

n Quantification and Reporting of Low-doseand Other Heterogeneous Exposures. ICRUReport Number 86; 2013.

n Safety Requirements for ElectricalEquipment for Measurement, Control andLaboratory Use – Part 2-201: ParticularRequirements for Control Equipment. IEC61010-2-201 ed1.0; March 2013.

n Information Technology: ProgrammingLanguages – Guidance to Avoiding


HISTORICAL FEATURE

W. Alan Jennings (Former Head, Division of Radiation Science, National

Physical Laboratory) on an event reported in the Daily Express in January 1984

Covering-up a great atomleak: tabloid scare stories

here have been many ‘radiation leak’incidents over the years, but for sheermagnification the following story must behard to beat (figure 1). Indeed, it may bedifficult to believe, but it is entirely factual. It

relates to an event at the National Physical Laboratoryin Teddington in 1984.

Whilst monitoring an old laboratory building onceused for radiochemical work, including the analysis ofuranium ore, a small patch of radioactivity wasdetected on the concrete floor. The radiation level, dueto S-rays (which scarcely penetrate a piece of paper),was trivial but nevertheless correctly reported tomanagement. In accordance with good practice, thebuilding concerned was temporarily closed as aprecautionary measure. Unfortunately this meant thatthe staff concerned could not retrieve their belongings.As a result subsequent conversations between them atthe nearby Queen Dowager public house were bychance overheard and reached the ears of the press.Sensing a ‘radiation leak’ story, the press proceeded toferret for information from all possible sources, fromthe landlord of the public house to Whitehalldepartments who had yet to hear about the issue. TheS-activity in question was bound to the host surfaceand therefore could not be ingested or inhaled. In fact,from the standpoint of the public, the matter wasmanifestly irrelevant.

However, on Thursday 19th January 1984, the DailyExpress, claiming an ‘exclusive’, ‘revealed all’ with anincredible and utterly irresponsible banner headline onits front page where it claimed a great cover-up hadmasked an ‘atom leak’ and that it was not safe forfamilies near the ‘secret’ laboratory.

Contents of the report

A 2-page report included the following points:n A radiation leak shut down part of a secret researchlaboratory in the London suburbs.n Uranium, which could kill, was found in a buildingclose to homes. The laboratory is very close toresidential streets and a school.n Radiation levels 100 times greater than backgroundlevels were found in the building (attributed to anemployee who ‘must remain anonymous’).n Too much radiation can lead to cancer. They purportthat these levels would cause 100 times more cancers in

the population (attributed to Dr William Connel of‘Friends of the Earth’).n Public concern will be increased about sitinglaboratories close to houses and schools.n People in North London are already campaigningagainst plans to switch research on dangerousdiseases from Porton Down, Wiltshire, to Colindale.This incident may anger them further.

The following day, 20th January, the Daily Expressran another article which claimed that six radiationworkers were at risk from a new leak and there wouldbe a top level investigation at Aldermaston. It name-checks the leak of the previous day and the associated‘cover-up’.

Further ‘stories’

This led to an editorial in the same issue headed‘Away with this secrecy’. Attacking the nuclear energybusiness, it claimed that its ‘record of cover ups isappalling. Small wonder that it provides grist for thescaremongering mills of sensationalist filmmakers’.

On the same day, 20th January, the Daily Mirror alsoreported the Aldermaston story, together with aneditorial headed ‘The secret horror’, with references toAldermaston, NPL and Winscale – thereby equatingNPL with other centres whose activities do not enjoywhole-hearted public support (as with Porton Downabove).

It is of course this type of journalism – known as‘horror story’ writing – which is appalling.

Such stories exaggerate, distort or falsifyinformation in a way that makes captivating readingbut, at the same time, undermines trust in theinstitutions concerned, particularly scientific ones.

In the present instance, the impact at NPL of suchtabloid sensational scare mongering was dramatic:n In the late evening (18th January) prior to the Daily

TFIGURE 1.

‘Radiation leak’incidents‘covered up’

▼

‰

Such stories exaggerate,distort or falsify information ina way that makes captivating

reading but undermines trust inthe institutions“ “


HISTORICAL FEATURE

Express’s so-called ‘revelations’, the media, includingBBC and ITV television crews, besieged the NPLgates, presumably through some planned leak or tipoff, to witness events at first hand.n First thing in the morning of the 19th January, DrPaul Dean, Director of NPL, and others were urgentlysummoned to Whitehall by Norman Tebbit, Secretaryof State, to brief Kenneth Baker, the Minister directlyresponsible for the NPL, to respond to a privatenotice question tabled for that afternoon by TobyJessel, the MP for Twickenham, in whoseconstituency the laboratory was sited. A House of

Lords question was also tabled on that day. Thediscussion is recorded in Hansard (19th January).Factual answers were given to the Daily Expressallegations in order to reassure MPs, some of whomreferred to levels of anxiety in their constituencies.n At Kenneth Baker’s request, as Minister forInformation Technology, a public meeting was heldinvolving local residents and other interestedparties.n The forthcoming laboratory children’s Christmasparty, normally held in late January, was cancelled.n ‘STOP MAKING ATOM BOMBS’ was daubed on alibrary window facing a public road which crossesthe laboratory grounds.n The impact of the whole episode was such thateven property values in neighbouring streets fell,and was illustrated in JAK’s cartoon in the EveningStandard (figure 2).

It took some months for the situation to return tonormal. Once the public mind is infected with someirrational belief, it is indeed very hard to control.

FIGURE 2.

JAK’s cartoon inthe EveningStandard

▼

‘STOP MAKING ATOMBOMBS’ was daubed on a

library window facing a publicroad which crosses the

laboratory grounds“ “‰

Image ©

Jak [Raym

ond Jackson] / Associated New

spapers Ltd

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