a novel device for the treatment of accessible tumours - papillon+...

1-26

KS Armoogum1, JA Mills2, S Devic3,MA Jahan4, DAL Morgan4

1Dept. of Radiotherapy Physics, Royal Derby Hospital, UK2Megavoltage Acceptance and Commissioning Services, Hinckley, UK

3Dept. of Radiation Oncology, SMBD Jewish General Hospital, Montréal, Canada4Division of Surgery, Kings Mill Hospital, Sutton-in-Ashfield, UK




A novel device for the treatment ofaccessible tumours - Papillon+ ™

x-ray brachytherapy system



7th UK Radiation Oncology ConferenceNottingham, 21 - 23 October 2013

2-26

Clinical AimClinical AimIntraoperative radiotherapy (IORT) using a miniature x-raysource has been shown to impart the same clinical benefit

as external beam radiotherapy (EBRT), in a single fraction1,2.

Intraoperative radiotherapy (IORT) using a miniature x-raysource has been shown to impart the same clinical benefit

as external beam radiotherapy (EBRT), in a single fraction1,2.

BenefitBenefitThe patient benefits are significant, since IORT replaces several weeks

of fractionated EBRT.

1.Targeted intraoperative radiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-Atrial): an international, prospective, randomised, non-inferiority phase 3 trial. JS Vaidya, DJ Joseph, FWenz et al. The Lancet 2010;376 (9735): pp. 91-102.

2.Targeted intraoperative radiotherapy for early breast cancer: TARGIT-A trial- updated analysis of localrecurrence and first analysis of survival. JS Vaidya, F Wenz, M Bulsara. Cancer Res 2012;72(24Suppl):S4-2.

3-26

Clinical RationaleClinical Rationale• Over 90% of local recurrences after breast conservative therapy occur

near the original tumour, even when radiotherapy is not given.Therefore, the remote occult cancer foci may be clinically irrelevant andradiotherapy to the index quadrant alone might be sufficient [6].

4-26

IntraOperative RadioTherapy (IORT) is defined as the delivery of asingle, large radiation dose to the bed of a resected tumour at the timeof surgical intervention.

In early stage breast cancer, IORT avoids unnecessary irradiation ofthe whole breast and reduces cardiac dose.

What is IORT?What is IORT?

5-26

Papillon+ X-Ray Brachytherapy SystemPapillon+ X-Ray Brachytherapy System

6-26


7-26

The anode is made of tungsten (Z =74). This tungsten anode is very thin (6μm) and works as a transmissionanode.The tube is cooled using an oil circuit,which allows the machine to dissipateheat and reach a high dose rate.

A temperature sensor preventsoverheating of the tube by controllingthe cooling time. With this controlledDuty Cycle, the stability in the dose rateis achieved.

The anode is made of tungsten (Z =74). This tungsten anode is very thin (6μm) and works as a transmissionanode.The tube is cooled using an oil circuit,which allows the machine to dissipateheat and reach a high dose rate.

A temperature sensor preventsoverheating of the tube by controllingthe cooling time. With this controlledDuty Cycle, the stability in the dose rateis achieved.


8-26

Electrons are electrostatically focussed, accelerated and travel alonga cylindrical tube onto a tungsten target producing a near-sphericaldistribution of x-rays.

The tube is sealed with aberyllium window producing inherentfiltration of 0.2 mm Al which increasesbeam penetration through removal oflow energy x-rays.

When it is not used, the tube is stored in a shielded tube. This parkingtube can also be used to test the x-ray emission.

Electrons are electrostatically focussed, accelerated and travel alonga cylindrical tube onto a tungsten target producing a near-sphericaldistribution of x-rays.

The tube is sealed with aberyllium window producing inherentfiltration of 0.2 mm Al which increasesbeam penetration through removal oflow energy x-rays.

When it is not used, the tube is stored in a shielded tube. This parkingtube can also be used to test the x-ray emission.


9-26

Papillon+ Console IPapillon+ Console I

10-26

Papillon+ Console IIPapillon+ Console II

11-26

Papillon+ Console IIIPapillon+ Console III

12-26

Papillon+ Product SpecificationsPapillon+ Product Specifications

14-26

Clinical ProcedureClinical Procedure

15-26

1. Why is HDR X-Br effective?

2. Is HDR X-Br clinically equivalent to EBRT?

3. How do you compare the two modalities?

1. Why is HDR X-Br effective?

2. Is HDR X-Br clinically equivalent to EBRT?

3. How do you compare the two modalities?

HDR X-Br 20Gy/1#vs.

EBRT 50Gy/25#

16-26

1. Why is HDR X-Br effective?1. Why is HDR X-Br effective?

Lea-Catchside Factor

T = Treatment Time

If T

17-26

Clinical RBE of HDR X-BrClinical RBE of HDR X-Br

DJ Brenner, CS Leu, JF Beatty, RE Shefer. Clinical relative biological effectiveness oflow-energy x-rays emitted by miniature x-ray devices. Phys. Med. Biol. Vol 44, pp 323-33, 1999.

As G1RBE

18-26

“Clinical trials have demonstrated the safety and efficacyof some forms of partial breast irradiation in selectedpatients.”

13th St Gallen International Breast Cancer Conference(March 2013)

2. Is IORT clinically equivalent to EBRT?2. Is IORT clinically equivalent to EBRT?

19-26

3. How do you compare the two modalities?3. How do you compare the two modalities?

Not easy to make a direct comparison. Need a common metric tocompare the two.What are the targets?

Firstly, if we consider only clonogens as targets, their distribution isvery uncertain, but might well be described by an inverse squarefunction. This in turn might depend significantly on biological featuressuch as molecular phenotype.

Secondly, there are a number of reasons for thinking that the truebiological target might include some components of the tumourmicroenvironment, which might well be concentrated near the excisionmargins rather than at depth.

Not easy to make a direct comparison. Need a common metric tocompare the two.What are the targets?

Firstly, if we consider only clonogens as targets, their distribution isvery uncertain, but might well be described by an inverse squarefunction. This in turn might depend significantly on biological featuressuch as molecular phenotype.

Secondly, there are a number of reasons for thinking that the truebiological target might include some components of the tumourmicroenvironment, which might well be concentrated near the excisionmargins rather than at depth.

20-26

Common metric – ‘Point of Isoeffect’Common metric – ‘Point of Isoeffect’

40Gy

21-26

Common metric – ‘Point of Isoeffect’Common metric – ‘Point of Isoeffect’

Early BreastCancer Trialists’CollaborativeGroup (EBCTCG)showed a reductionin 10-yr incidenceof local recurrencesto 10%.

Point ofIsoeffect

22-26

Radiation Protection IRadiation Protection I

1. With the applicator in the patient and with no additional shielding,the dose rate at 3m was 1390 uSvh-1 (Calculated using ISL).

2. With the applicator in the patient and with additional shielding (0.35mm Pb), the dose rate at 5m was 7.2 uSvh-1.

NB: It is desirable to keep the dose rate below 7.5 uSvh-1 (ALARA)

1. With the applicator in the patient and with no additional shielding,the dose rate at 3m was 1390 uSvh-1 (Calculated using ISL).

2. With the applicator in the patient and with additional shielding (0.35mm Pb), the dose rate at 5m was 7.2 uSvh-1.

NB: It is desirable to keep the dose rate below 7.5 uSvh-1 (ALARA)

23-26

Radiation Protection IIRadiation Protection II

1. Recommended to use mobile Pb-glass screens (0.35 mm Pb) inTheatre.

2. Typical ‘beam on’ time will be 2 minutes (0.24 µSvh-1)

3. Treating 3 patients per session 0.72 µSvh-1

4. Would have to treat 1250 patients to exceed 300 µSv in a year

5. Remote monitoring system so no one needs to remain in Theatre

1. Recommended to use mobile Pb-glass screens (0.35 mm Pb) inTheatre.

2. Typical ‘beam on’ time will be 2 minutes (0.24 µSvh-1)

3. Treating 3 patients per session 0.72 µSvh-1

4. Would have to treat 1250 patients to exceed 300 µSv in a year

5. Remote monitoring system so no one needs to remain in Theatre

24-26

AcceptanceAcceptance

• There will be initial scepticism to IORT.

• IORT increases anaesthetic time (elderly, infirm patients).

• Theatres need to be efficient.

• IORT Nurse Coordinator important.

• Acceptance increases with time.

• Practice becomes routine.

• There will be initial scepticism to IORT.

• IORT increases anaesthetic time (elderly, infirm patients).

• Theatres need to be efficient.

• IORT Nurse Coordinator important.

• Acceptance increases with time.

• Practice becomes routine.

25-26

ConclusionConclusion

The Papillon+ offers a clinical alternative to mastectomy for older breastcancer patients.

Beam characteristics enable delivery of treatments similar to thosereported in literature.

A major advantage is the high (> 12 Gy/min) dose rate facilitatingdelivery of 20 Gy to the breast tumour bed in < 2 minutes – a majoradvantage from a clinical perspective.

The Papillon+ offers a clinical alternative to mastectomy for older breastcancer patients.

Beam characteristics enable delivery of treatments similar to thosereported in literature.

A major advantage is the high (> 12 Gy/min) dose rate facilitatingdelivery of 20 Gy to the breast tumour bed in < 2 minutes – a majoradvantage from a clinical perspective.

26-26

References

1.C Herskind, J Griebel, U Kraus-Tiefenbacher, F Wenz. Sphere of Equivalence – ANovel Target Volume Concept for Intraoperative Radiotherapy using Low Energy X-Rays. Int. J. Radiation Oncology Biol. Phys. 72(5); 2008: pp 1575-81.

2.J Vaidya, J Vyas, R Chinoy, N Merchant, O Sharma, I Mittra. Multicentricity ofbreast cancer: whole-organ analysis and clinical implications. British Journal ofCancer 74; 1996: pp 820-24.

3.J Vaidya, D Joseph, J Tobias, M Bulsara, F Wenz et al. Targeted intraoperativeradiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-A trial): aninternational, prospective, randomised, non-inferiority phase 3 trial. Lancet.Published Online June 5, 2010; DOI:10.1016/S0140-6736(10)60837-9.

4.J Vaidya, J Tobias, M Baum, M Keshtgar, D Joseph et al. Intraoperativeradiotherapy for breast cancer. The Lancet Oncology, Volume 5(3); 2004: pp 165–73.

5.B Belletti, J Vaidya, S D'Andrea. Targeted Intraoperative Radiotherapy Impairs theStimulation of Breast Cancer Cell Proliferation and Invasion Caused by SurgicalWounding. Clin Cancer Res. 14; 2008: pp 1325-32.

6.J Vaidya. A novel approach for local treatment of breast cancer. Dissertation forthe Degree of Doctor of Philosophy. University College London 1996-2001.











7th UK Radiation Oncology ConferenceNottingham, 21 - 23 October 2013

a novel device for the treatment of accessible tumours - papillon+...

Documents