intensity-modulated radiation therapy using serial tomotherapy · • the amazing the incredible...

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IntensityIntensity--Modulated Modulated Radiation Therapy Using Radiation Therapy Using

Serial Serial TomotherapyTomotherapy

Bruce CurranBruce CurranUniversity of MichiganUniversity of Michigan

Ann Arbor, MIAnn Arbor, MI

Overview Overview

Introduction / Brief HistoryIntroduction / Brief HistoryCharacteristicsCharacteristics

Advantages / ConstraintsAdvantages / Constraints

ImplementationImplementationInstallation / CommissioningInstallation / CommissioningDaily Setup / Patient QADaily Setup / Patient QA

Clinical ResultsClinical Results

AcknowledgementsAcknowledgements

UCSF (UCSF (XiaXia et al)et al)NOMOS CorporationNOMOS CorporationWashington U (Low et al)Washington U (Low et al)Tomotherapy Inc. (Rock Mackie et al)Tomotherapy Inc. (Rock Mackie et al)

•• The Amazing The Incredible The Amazing The Incredible SuperdogSuperdogWritten by Crosby Written by Crosby BonsallBonsallPublished by HarperPublished by Harper

In the last decade, I have become increasingly concerned with tIn the last decade, I have become increasingly concerned with the rapid he rapid development of advanced radiotherapy treatment techniques. development of advanced radiotherapy treatment techniques. Unfortunately, the motivation for this expansion appears to be mUnfortunately, the motivation for this expansion appears to be market arket driven ("Come receive treatment at OUR centre, where we offer driven ("Come receive treatment at OUR centre, where we offer IMRT, etc. ..."). This U.S.IMRT, etc. ..."). This U.S.--initiated trend is now beginning to spread initiated trend is now beginning to spread to Canada and Western Europe.to Canada and Western Europe.

Can an isolated physicist at a remote clinic achieve the same coCan an isolated physicist at a remote clinic achieve the same confidence nfidence and expertise found at a larger institute? Are we not doing patand expertise found at a larger institute? Are we not doing patients a ients a disservice by employing devices and/or techniques without a totadisservice by employing devices and/or techniques without a total l understanding of their use?understanding of their use?

Jack CunninghamJack Cunningham

MedPhysMedPhys ListServerListServer Thread Thread

. . . However, after our experience with what I refer to as true. . . However, after our experience with what I refer to as trueIMRT (the binary operated collimator with multiple IMRT (the binary operated collimator with multiple independently controlled independently controlled beamletsbeamlets), I must confess that our ), I must confess that our clinical results have been extremely satisfying. Four plus clinical results have been extremely satisfying. Four plus years after treatment, we have many cases where there is no years after treatment, we have many cases where there is no sign of sign of xerostomiaxerostomia or or tumourtumour recurrence. The patients are recurrence. The patients are happy, we are happy and their dentists are very happy. happy, we are happy and their dentists are very happy. Similarly with abdominal treatments. We do not observe the Similarly with abdominal treatments. We do not observe the typical bowel complications. Again the patients are much typical bowel complications. Again the patients are much happier and so of course are we. . . .happier and so of course are we. . . .

Darrell O. PooleDarrell O. Poole

MedPhysMedPhys ListServerListServer ThreadThread Brief History Brief History

Early Theoretical WorkEarly Theoretical WorkBrahmeBrahme ((RadiotherRadiother. . OncolOncol. 12, 1988). 12, 1988)BortfeldBortfeld (Phys. Med. Biol. 35, 1990)(Phys. Med. Biol. 35, 1990)

Initial DevelopmentInitial DevelopmentSwerdloffSwerdloff, Holmes, Mackie (U , Holmes, Mackie (U WiscWisc))Carol, Campbell, Carol, Campbell, ScherchScherch (NOMOS Corp)(NOMOS Corp)

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Brief History Brief History

Initial Clinical ImplementationInitial Clinical ImplementationGrant, Butler (TMH / Baylor)Grant, Butler (TMH / Baylor)Tsai, Curran, Tsai, Curran, WazerWazer (NEMC / Tufts)(NEMC / Tufts)Low, Low, MuticMutic, , ChaoChao (MIR / Washington U)(MIR / Washington U)

Current StateCurrent State~120 Clinical Systems in Use (10,000 patients)~120 Clinical Systems in Use (10,000 patients)~15 Helical Tomotherapy Systems in process~15 Helical Tomotherapy Systems in process

What is Serial What is Serial TomotherapyTomotherapy??

INTENSITY-MODULATED RADIOTHERAPY:CURRENT STATUS AND ISSUES OF INTEREST

Intensity Modulated Radiation Therapy Collaborative Working GroupInt. J. Radiation Oncology Biol. Phys., Vol. 51, No. 4, pp. 880–914, 2001

Tomotherapy: The delivery of intensity modulated rotating fan beams. • Serial tomotherapy is the delivery of multiple fan

beams with discrete table increments between each axial gantry arc.

• Helical tomotherapy makes use of helical CT type motions (continuous synchronized gantry and table motion).

IntensityIntensity--Modulated TreatmentModulated Treatment

Tomotherapy DeliveryTomotherapy Delivery

Courtesy, NOMOS Corporation



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Serial TomotherapySerial Tomotherapy

Courtesy, West Penn Hospital

Why Use Tomotherapy?Why Use Tomotherapy?

Allows large search space of possible Allows large search space of possible beamletsbeamlets55/27 beam positions per 29055/27 beam positions per 290°° arc (5arc (5°° or 10or 10°° steps)steps)20 20 beamletsbeamlets per position (1,100 per position (1,100 beamletsbeamlets/arc)/arc)11 intensity levels for each 11 intensity levels for each beamletbeamlet (0 (0 –– 100%)100%)

Large gantry angle space for finding tangentsLarge gantry angle space for finding tangentsEfficient delivery with complex modulationEfficient delivery with complex modulation

Modulation complexity does not affect MUModulation complexity does not affect MU

Clinical Comparisons Clinical Comparisons –– II II

Brain tumor Brain tumor -- GBMGBM75 y.o. Asian female w. dizziness, weakness and gait 75 y.o. Asian female w. dizziness, weakness and gait disturbancedisturbanceLeft Left cerebellarcerebellar mass on MRI and CTmass on MRI and CT--guided biopsyguided biopsy

Dose constraints:Dose constraints:60 60 GyGy to GTVto GTV45 45 GyGy max to BS and optic chiasmmax to BS and optic chiasm

Plan comparisons:Plan comparisons:3 3 fldfld nonnon--coplanar 3D plan (Pinnacle) vs. coplanar 3D plan (Pinnacle) vs. IMRTIMRT-- MIMiC (Corvus) vs. MIMiC (Corvus) vs. 5 5 fldfld MLCMLC--IMRT (Corvus)IMRT (Corvus)

Courtesy, UCSF

3D-CRT IMRT-MIMiC

60 Gy, 45 Gy, 30 Gy

IMRT-MLC

Courtesy, UCSF

3D-CRT IMRT-MIMiC

60 Gy, 45 Gy, 30 Gy

IMRT-MLC

Courtesy, UCSF

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3D-CRT IMRT-MIMiC

60 Gy, 45 Gy, 30 Gy

IMRT-MLC

Courtesy, UCSF

3D-CRT IMRT-MIMiC

60 Gy, 45 Gy, 30Gy

IMRT-MLC

Courtesy, UCSF

3D-CRT IMRT-MIMiC

60 Gy, 45 Gy, 30 Gy

IMRT-MLC

Courtesy, UCSF ASO

RPOLPO

Courtesy, UCSF

LAO LAT

LPO RPO

AP

Courtesy, UCSF

0.0

25.0

50.0

75.0

100.0

125.0

% V

olum

e

0

2000

4000

6000

8000

Dose (cGy)

Brain

BS/MLCBS/3dBS/IMRT

ChiasmChiasm/3dChiasm/IMRT

Courtesy, UCSF

5

0.0

25.0

50.0

75.0

100.0

125.0

% V

olum

e

0

2000

4000

6000

8000

Dose (cGy)

Brain

Brain/MLC

GTV/MLC

Brain/3d

GTV/3d

Brain/IMRT

GTV/IMRT

Courtesy, UCSF

Comparison Results Comparison Results –– II II Brain Brain

Much reduced dose to brainstem for IMRT Much reduced dose to brainstem for IMRT compared to 3D (MIMiC better than MLCcompared to 3D (MIMiC better than MLC--IMRT)IMRT)

dosedose--limiting structure for this tumorlimiting structure for this tumor

IMRT plans more conformal than 3D with less IMRT plans more conformal than 3D with less dose to brain outside GTVdose to brain outside GTV

could be particularly important for pediatric could be particularly important for pediatric patientspatients

Courtesy, UCSF

ConclusionsConclusions

• In general, MIMiC Plans are more conformal than MLC-IMRT plans.

• Requirement in patient immobilization for MIMiC treatment is more stringent, especially for intra-treatment movement.

• Couch index error can produce significant dose error and rigorous QA procedure is necessary.

Courtesy, UCSF

TomotherapyTomotherapy Delivery ExampleDelivery Example

Courtesy, Rock Mackie

Tomotherapy ConstraintsTomotherapy Constraints

•• Rotational Speed AccuracyRotational Speed Accuracy•• MU/Degree AccuracyMU/Degree Accuracy•• Slice Indexing AccuracySlice Indexing Accuracy•• Whole Body Dose / ShieldingWhole Body Dose / Shielding•• ImmobilizationImmobilization•• Delivery TimeDelivery Time

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2% / 0.1mm Accuracy Requirement (Low et al)



The head and wholeThe head and whole--body phantom used to body phantom used to measure the wholemeasure the whole--body dose databody dose data

Courtesy, Wash U of St. Louis

Scatter and leakage dose distribution along Scatter and leakage dose distribution along the gantry axis of rotationthe gantry axis of rotation

0

1

2

3

0 10 20 30 40 50

Internal Scatter and LeakageLeakage Alone

Dose

(per

cent)

Z (mm)Courtesy, Wash U of St. Louis

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WholeWhole--body dose equivalent (40 cm from field body dose equivalent (40 cm from field edge): 70 edge): 70 GyGy target dosetarget dose

FollowillFollowill et al.et al. -- 543 543 mSvmSv -- Three arcs, 20 X 20 cm Three arcs, 20 X 20 cm 22 fixed fixed beam data, and 3.24 MU cGybeam data, and 3.24 MU cGy--11 per arcper arcOur calculation Our calculation -- 315 315 mSvmSv -- Five arcs, 10 X 10 cm Five arcs, 10 X 10 cm 22 fixed fixed beam data, and 1.8 MU cGybeam data, and 1.8 MU cGy--11 per arcper arcOur measurements Our measurements -- 271 271 mSv mSv


Conclusions (Low et al) Conclusions (Low et al)

Estimated fatal secondary cancer (fatal leukemia) due to a Estimated fatal secondary cancer (fatal leukemia) due to a 70 70 GyGy course of radiation therapy:course of radiation therapy:

Conventional TherapyConventional Therapy 0.4%0.4%FollowillFollowill et al. et al. –– TomotherapyTomotherapy 2.8%2.8%Measured Measured -- TomotherapyTomotherapy 1.4%1.4%



•• Rotational Speed AccuracyRotational Speed Accuracy•• MU/Degree AccuracyMU/Degree Accuracy•• Slice Indexing AccuracySlice Indexing Accuracy•• Whole Body Dose / ShieldingWhole Body Dose / Shielding•• ImmobilizationImmobilization•• Delivery TimeDelivery Time 0 Minutes 15 Minutes later 30 Minutes later

Three Sets of Orthogonal FilmsThree Sets of Orthogonal Films

Courtesy, UCSF

0 Minutes 15 Minutes later 30 Minutes later

Three Sets of Orthogonal FilmsThree Sets of Orthogonal Films

Courtesy, UCSF



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Delivery Time IssuesDelivery Time Issues

Accurate IndexingAccurate IndexingMultiple Rotations / TreatmentMultiple Rotations / TreatmentDose RateDose RateMU EfficiencyMU Efficiency


Implementation of Serial Implementation of Serial TomotherapyTomotherapy

Currently available from a single vendorCurrently available from a single vendorNOMOS Corporation, Cranberry NOMOS Corporation, Cranberry TwnshpTwnshp, PA, PA



Installation / CommissioningInstallation / Commissioning

Mechanical InstallationMechanical InstallationPower & Air Cabling through gantryPower & Air Cabling through gantryTable indexing apparatusTable indexing apparatusMIMiCMIMiC Alignment pins / attachmentAlignment pins / attachment

CommissioningCommissioningAlignmentAlignmentIndex determinationIndex determination

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Radial Alignment Film(90 / 270 gantry angle w/ film 15cm off isocenter

Transverse Alignment Film(90 / 270 checkerboard w/ film at isocenter

Alignment FilmsAlignment Films Indexing Test Indexing Test

Serial Serial TomotherapyTomotherapy ExampleExample

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University of Texas Health Science Center / Cancer Therapy and Research Center (CTRC)San Antonio, Texas


1998

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Clinical CasesClinical Cases

Tomotherapy MLC

Tomotherapy MLCCraniopharyngioma encompassing the optic chiasm

Acoustic neuroma adjacent to brain stem

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Mediastinal mass with sparing of bronchus

Meningioma with sparing of optic nerve

Thank youThank you

intensity-modulated radiation therapy using serial tomotherapy · • the amazing the incredible...

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