alan pollack, m.d., ph.d. mr simulation university of ... 1 alan pollack, m.d., ph.d. university of...

Alan Pollack, M.D., Ph.D.Alan Pollack, M.D., Ph.D.University Of MiamiUniversity Of Miami

Sylvester Comprehensive Cancer CenterSylvester Comprehensive Cancer Center

MR Simulation For MR Simulation For Prostate CancerProstate Cancer

MR SimulationMR Simulation

�� Prostate AnatomyProstate Anatomy

�� MRMR--CT FusionCT Fusion

�� Functional ImagingFunctional Imaging

�� Therapeutic ImplicationsTherapeutic Implications

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The Benefit Of MRIThe Benefit Of MRI

�� Prostate ApexProstate Apex��ProstateProstate--rectal interfacerectal interface

�� Penile BulbPenile Bulb�� Tumor Location/ExtentTumor Location/Extent�� BladderBladder--Prostate InterfaceProstate Interface�� Seminal vesiclesSeminal vesicles�� Pelvic vesselsPelvic vessels�� Lymph nodesLymph nodes 44

Prostate AnatomyProstate AnatomyMcLaughlin et al, IJROBP 2005McLaughlin et al, IJROBP 2005

Prostate AnatomyProstate AnatomyMcLaughlin et al, McLaughlin et al,

IJROBP 2005IJROBP 2005

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Case 3 High Risk Case 3 High Risk CTCT--SagSagApex Not WellApex Not Well--VisualizedVisualized

77

Case 3 High Risk Case 3 High Risk MRIMRI--SagSagApex Better VisualizedApex Better Visualized

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Case 3 High Risk CoronalCase 3 High Risk CoronalCTCT

Case 3 High Risk CoronalCase 3 High Risk CoronalMRIMRI

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CT Overestimates Prostate CT Overestimates Prostate VolumeVolume

�� Roach et al, IJROBP 1996:Roach et al, IJROBP 1996:��““The mean prostate volume was 32% largerThe mean prostate volume was 32% larger…”…”

by CTby CT

�� RaschRasch et al, IJROBP 1999: et al, IJROBP 1999: ��The The ““average ratio between the CT and MR average ratio between the CT and MR

volumes was 1.4volumes was 1.4””��““CTCT--derived prostate volumes are larger than MR derived prostate volumes are larger than MR

derived volumes, especially toward the seminal derived volumes, especially toward the seminal vesicles and the apex of the prostate.vesicles and the apex of the prostate.””

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Retrograde Retrograde UrethrogramUrethrogram vsvs MRI MRI For Defining The Prostate ApexFor Defining The Prostate Apex

Rasch et al, IJROBP 1999

� Milosevic et al 1998 Radioth Oncol: ∼∼∼∼ 80% agreement between CT urethrogram and MR. 1212

MRI MRI vsvs CT: GTV DelineationCT: GTV Delineation

MR CT

Case 3 High Risk: Slice 89Case 3 High Risk: Slice 89

Tumor

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Penile Bulb/Penile Bulb/CavernosalCavernosal BodiesBodies

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MRI vs. CT: Hip ReplacementMRI vs. CT: Hip Replacement MR SimulationMR Simulation





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Page


�� No fiducials or Gold fiducials :No fiducials or Gold fiducials :�� CT Sim FirstCT Sim First

�� Calypso BeaconsCalypso Beacons�� MR Sim firstMR Sim first

�� Fusion based on bone and Fusion based on bone and soft tissue. soft tissue.

• Retrograde urethrograms are not performed.

1.5 T, 60 cm bore

Courtesy of Bob Price

Contoured on CT

Contoured on MR

MR-CT fusion based on boney anatomy

MR-based prostate-rectum interface

Mismatch arises from time of scan differences


CT-based prostate-rectum interface

Overlap (not including PTV)


CTMRI

Note that the prostate is in a different position relative to the femoral heads

MR And CT With Gold FiducialsMR And CT With Gold Fiducials


Page

CTMRI

Note that the prostate is in a different position relative to the femoral heads

CT With Calypso BeaconsCT With Calypso Beacons

Courtesy of Bob Price2222

MRMR--CT FusionCT Fusion

�� DonDon’’t outline from MR for soft tissue if there t outline from MR for soft tissue if there is discrepancy in the soft tissueis discrepancy in the soft tissue��Fusion should be based on both soft tissue and Fusion should be based on both soft tissue and

bony anatomybony anatomy

�� Gold markers on MR and CT can aid in soft Gold markers on MR and CT can aid in soft tissue fusiontissue fusion

�� Calypso beacons are on CT only and MR Calypso beacons are on CT only and MR should only be used as a reference (all should only be used as a reference (all outlining from CT)outlining from CT)

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How Can BulkyHow Can Bulky--HypoxicHypoxic--MicrovesselMicrovessel Dense Dense Areas Be Identified And Better Targeted?Areas Be Identified And Better Targeted?

�� MRMR��MRS, Bold, DCE, DWMRS, Bold, DCE, DW

�� PETPET��11C11C--Choline, 11CCholine, 11C--AcetateAcetate

�� SpectSpect��PSMAPSMA

Testa et al, Radiology 2007

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Imaging To Identify Bulky Imaging To Identify Bulky Tumor RegionsTumor Regions

�� PretreatmentPretreatment��Target with EBRT boost, Target with EBRT boost, EBRT+BrachyEBRT+Brachy boost, boost,

EBRT+CryosurgeryEBRT+Cryosurgery boost, EBRT+FUS boostboost, EBRT+FUS boost�� MRMR--Guided FUSGuided FUS

��Reduce incidence of Reduce incidence of BxBx+ at 2+ at 2--3 yr3 yr

�� PostPost--treatmenttreatment��Biopsy at 2Biopsy at 2--3 years3 years

�� Decision to Decision to BxBx based on imaging?based on imaging?�� Target residual tumor before PSA riseTarget residual tumor before PSA rise

�� Treatment of residual tumor cells onlyTreatment of residual tumor cells only

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Is Failure Related To High Is Failure Related To High Volume Areas?Volume Areas?

�� TZTZ-- Left: 0/0Left: 0/0�� TZTZ--Right: 0/0Right: 0/0

3+41/15%

4+31/130%

4+31/170%

4+31/120%

0/1

0/13+41/1<5%

0/1

0/14+31/150%

Left

Base

Mid

Apex

Right

0/13+41/150%

Target with imaging

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PostPost--Treatment Biopsy ResultsTreatment Biopsy Results

�� TZTZ-- Left: 0/0Left: 0/0�� TZTZ--Right: 0/0Right: 0/0

0/1

0/14+31/115%

0/1

0/1

0/10/1

0/1

0/10/1

Left

Base

Mid

Apex

Right

0/13+41/15%

Target with imaging

�� 9 Patients9 Patients�� PrePre--RT and PostRT and Post--RT MRIRT MRI�� Salvage ProstatectomySalvage Prostatectomy

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PucarPucar et al, IJROBP 2007et al, IJROBP 2007

3131 3232

I

S

BoostTarget

ProstateProstate

BoostTarget

76 Gy, 68, 61, 53, 46, 38 76 Gy, 68, 61, 53, 46, 38

Price & Pollack

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Boost

10 Gy, 9, 8, 7, 6, 5

30 Gy, 27, 24, 21, 18, 15

10 Gy, 9, 8, 7, 6, 5

30 Gy, 27, 24, 21, 18, 15

EQD2 = EQD2 = D[(dD[(d + (+ (αα//ββ ))/(2 + ())/(2 + (αα//ββ ))] = 30 ))] = 30 GyGy {{αα//ββprostateprostate = 2.0 = 2.0 GyGy}}

Price & Pollack

3535

Pickett et al, MRSI In FollowPickett et al, MRSI In Follow--up up After EBRTAfter EBRT

Pretreatment

Post-treatment

3636

Lymphotropic SuperparamagneticNanoparticle lymph node imaging

agents (Combidex)3838

Benign : Post-contrastPre-contrast

Pre-contrast Malignant : Post-contrast

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MR Imaging For Prostate CancerMR Imaging For Prostate Cancer

�� There are gains in the use of MR There are gains in the use of MR imaging in RT planning and delivery, imaging in RT planning and delivery, and in followand in follow--up.up.

�� Need to test and incorporate better Need to test and incorporate better imaging methods for identifying imaging methods for identifying bulkybulky--hypoxichypoxic--microvesselmicrovessel dense dense diseasedisease

alan pollack, m.d., ph.d. mr simulation university of ... 1 alan pollack, m.d., ph.d. university of...

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