Prostate Cancer G Bauman

Achieving the
Acheivable:
Prostate
Glenn Bauman, MD
Associate Professor and Chair,
Department of Oncology
London Regional Cancer Program
University of Western Ontario

A Cancer Care Ontario Partner

Objectives
• We’re we’ve been
• What we’ve learned
• What we should do
• Where we should go
• External beam
• Brachytherapy
• Postoperative radiotherapy
• Related issues


The Future is a Moving Target…


Where we’ve been…


What we’ve learned….
JCO 23:2005


What we’ve learned….

Risk stratification
• Low risk
• T1-T2; PSA<10; Gleason<6
• (% cores or PSA velocity*)
• Intermediate risk
• T1/T2; PSA<20; Gleason <7; not otherwise low risk
• (% cores or PSA velocity*)
• High risk
• PSA >20 or T3 or Gleason >8;

>50% cores positive or PSA velocity >2ng/ml/yr upstages*


What we’ve learned…


EBXRT: Current Standard:
3D - conformal


CT simulation
• Simple immobilization sufficient
• Patient instructions for bladder/rectum filling
• Minimize iatrogenic perturbations
• Flag “outliers” (rectal volume or CSA)

Contouring conventions (prostate + OAR)
• Modality dependent
• Apex and base definition
• Seminal vesicles and nodes
• Wall vs. solid OAR


Sample patient data: Marker Motion (Ant/Post, Sup/Inf) from
Weekly Port Film

1.5

Urethrogram
1
Post/Ant direction (cm)

22-Aug
31-Jul 12-Aug
17-Jul 7-Aug
28-Aug
12-Jul
Urethrogram
12-Jul
12-Aug
0.5
31-Jul
7-Aug
22-Aug 28-Aug
17-Jul

Urethrogram 0
12-Aug
22-Aug
Prostate Left 31-Jul

Prostate Right 7-Aug
12-Jul 28-Aug
-0.5
Apex 17-Jul

-1
-3.5 -3 -2.5 -2 -1.5 -1 -0.5 0
Sup/Inf direction (cm)


Penile Bulb: anatomic marker


60 *
CT *
50 MR *
3DUS
^3)

*
40
olum (cm

* *
30
e

20
V

10

0
1 2 3 4 5 6 7 8 9 10
Patient number


GTV Delineation: Summary
Technique Advantages Limitations

CT Available/simple contouring (base/apex)

CT+ markers Apex; IG Invasive/base delineation

CT+ contrast Apex; base Systemic error

2D TRUS Contouring easy “not fuseable”

3D Ext US “fuseable”, IG inter-observer error

MRI “fuseable” Availability; not Rx


Planning: One approach
CTSIM Prep
• BM prior
• 500cc fluids
• no urethrogram
CTSIM; if large rectal volume
rectal tube or bathroom and reCT
Persistent large
rectal volume or
Hypofx: IGXRT

OARs and GTVs
PTVs generated; +/- pelvic fields
1cm margin; 0.7mm post if IGXRT
95% isodose coverage of PTV; 73Gy/35

SIB class solution or 3DCRT plan (IMRT if dose constraints not met)


Planning: One approach
73Gy/35 fraction
Phase I:
75-77Gy BED
50Gy/25

Phase II:
SIB selected based
on23Gy/10
% overlaps
25 Gy AP/PA 25 Gy R/L LAT

10 Gy AP/PA 10 Gy R/L LAT 3 Gy/R/L LAT


EBXRT Minimum Standards

• Every patient planned
• 3D dose distribution and DVH
• PTV and OAR DVH constraint based

• Choose a class solution and stick with it
• 4-6 field 3DCRT
• Motionmanagement strategy
• Minimum dose BED > 74 Gy
• PTV margins 1.0cm; 0.5-0.7 posterior


DVH Recommendations: PROFIT
• Wall volumes; dosimetric definition
• Rectal and Bladder wall: D50<53Gy and D30<71Gy

DVH Recommendations: RTOG P0126
• lumen volumes; anatomic definition


30 40 50 60 70 80

Anatomic
Effects of
variation of
“Dosimetric” contouring on
rectal DVH

100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
0 20 40 60 80 100


Clinical Data Supporting Conformal XRT

(www.cancercare.on.ccopgi.on)


Pollack
IJROBP
In Press


Future Trend: IMRT


MSKCC
81Gy; IMRT


Future Trend: 4D Adaptive RT
“If you can’t see it, you can’t hit it.
If you can’t hit it, you can’t cure it”
H.E. Johns or W. Powers

“If it’s moving, you can’t hit it.
If you can’t hit it, you can’t cure it”
J. Battista


Inter-fraction
variability in dose to
organ at risk
(rectum)


TCP

NTCP

5.9


Strategy: Tracking fiducial markers


Strategy: Daily U/S localization


Strategy: Daily CT localization


Future Trend: BTV Definition

CT, MRI,US fCT, PET/SPECT,
Tumour Cells fMRI Hypoxia

Proliferation

Composite
target


Dawson, Lancet Oncol, 7 2006

Future Trend: Target definition

IJROBP 67(2) 2007 347-355 IJROBP 63(4) 2005 1262-1269

Future trend: IMRT for Nodal XRT


Future trend: Hypofractionation
Tumor Control Probability (%)

Iso-late-complications

* Fowler J, et al. Int J Radiat Oncol Biol Phys 2003;56:1093-1104. Ontario Partner
A Cancer Care

Standards: Prostate I125

• Prostate Volume < 50 cc
• Clinical Stage T1c or T2a
• PSA < 10
• Gleason Score < 6
• No Nodal or distant metastases
• No previous TURP


Standards: Prostate I125
• Ultrasound Volume Study
• Pubic Arch Interference Assessment
• Pre-plan: 145Gy to periphery of prostate
• Ordering I-125 seeds and calibration
• Needle loading
• Ultrasound guided Implantation
• CT post-planning


IJRBOP 67(2): 2007 327-333; IJRBOP 67(2): 2007 334-341


Future trends: dose painting

Requirements:
• biological imaging and multi-modality fusion
• improved stereotaxis (robotic assisted?)
• patient selection


Future Trend


Future trends: HDR Prostate Brachytherapy
• int - high risk prostate
cancer
• Utilizes temporary
catheters; u/s guidance;
perineal template
• Iridium 192 delivers dose in
minutes
• Usually combined with
EBXRT (4-5 weeks)
• Invasive, hospitalization
overnight
• 1-3 fractions


Postoperative/Salvage Radiation

Postoperative:
• 3 RCT supporting adjuvant radiation
• pT3 or margin positive
Salvage
• Case series only (Stephenson, JAMA)
• Margin positive, PSA < 2.0, post RP kinetics

CTSIM; 60-66Gy/30=33; 3DCRT


Candidates
•Margin positive
•Seminal vesicle inv
•Extracapsular ext


Future trend: GTV definition


Future trends: BTV (again!)


RADICALS randomised comparisons:
Flow diagram
Radical prostatectomy All Groups

Assess need for RT

Immediate RT group Uncertain group

Immediate RT
RANDOMISE
Immediately after
surgery
RANDOMISE Immediately after surgery
Monitor on trial

RT + no AD RT + short AD RT + long AD

Trial follow-up Deferred RT group
(Monitored off trial, now PSA rising)
Deferred RT
At rising PSA RANDOMISE

RT + no AD RT + short AD RT + long AD

Trial follow-up

Time Outcome measures


What is needed?
• Common prep, contouring and DVH conventions
• Multi-modality GTV definition (U/S or MRI)
• IMRT enabled planning and LINACS
• Efficient IMRT class solutions and QA/QC
• Image guidance requirements:
• CL-PTV: repeat CTSIM and dosimetry capacity
• CT: CB or MVCT Unit
• U/S: US at LINAC and CTSIM
• Seed: Marker placement (radiology)

• RT training: image interpretation; action levels; correction


What else is needed – long term?
• Better predictors of toxicity/common databases
• Biological and functional multi-modality imaging
• Complete ongoing RCT
• Dose escalation and hypofractionation
• New RCT
• Multimodality (LDR/HDR/CTX/Sx)
• A new paradigm?
• “Prostate Lumpectomy” + regional XRT
• Patient decision aids
• EPR enabled follow-up


Changes in CaP XRT
• 66-70Gy • BED > 74 Gy • BED >78Gy
• 4 field; blocks • 4-6 fields; 3DCRT • IGXRT
• Fluoroscopic • CTSIM • IMRT
• DRE • Risk stratified, bDFS

• 3D CRT • IGXRT • Multi-modal
• LDR • HDR • BTV optimization
• Hypofx (Part I) • Dose escalation • Prostate SRT
• Models • Hypofx (Part II) • Gating

• MLC • dMLC • Multi-modal imaging
• TPS • EPI/US/CBCT/MVCT • Real time IGXRT
• CTS • MR SIM/CT-US SIM • Multi-modal TPS
• RVS • BTV TPS
• Fiducials


http://www.youtube.com/watch?v=LQqq3e03EBQ


Thank You!


Prostate Cancer G Bauman

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Prostate Cancer G Bauman