Workshop on Advanced Technologies in Radiation Oncology

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Workshop on Advanced Technologies in Radiation
Oncology

• Howard Sandler

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Prostate Cancer

• Model for use of advanced technologies
• Common, long follow-up, simple geometric
  relationship to critical structures

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Dose Limiting Toxicity

• Rectal toxicity
• What about bladder?

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Garg, et al. IJROBP 661294,2006
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Late Morbidity from Early Proton Study median
FU 13 yrs
Gardner, et al. MGH J Urol167123,2002
GI Morbidity
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50.4 photon 16.8 photon
50.4 photon 25.2 CGE proton
Shipley, et al. IJROBP 323,1995
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RTOG 9406?
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RTOG 9406

• 1084 patients from 34 institutions
• 36 had neoadjuvant hormonal rx
• By dose level, 5 yr OS is 89, 87, 88, 89,
  95

3-yr OS
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RTOG 9406 Biochemical Results
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RTOG 9406 Toxicity
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RTOG 9406 Toxicity

• Grade 3
• By dose level
• 4, 4, 5, 7, 10

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DVH
Dose- Volume Histogram
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Grade 2 Rectal Morbidity at 70 Gy
Huang, et al MD Anderson IJROBP 541314,2002
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Rectal Bleeding Requiring Laser Treatment or
Transfusion (3DCRT)
Peeters et al. IJROBP 611019, 2005
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Peeters et al. IJROBP 641151, 2006
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LKB Modelling of Dutch Study Uses Entire DVH
n 0.13, TD50 81 Gy, m 0.14, p0.025
Peeters et al. IJROBP 6611, 2006
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Rectal Constraint
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64 Gy 3 field Conv open Conf 16 mm
GTV-block margin 90 coverage HD vol reduced
by 40 Bladder toxicity NS
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Modelling Data from Marsden Trial

• Dose-surface histograms
• 79 pts available
• Physical dose converted using a/ß3
• 1000 points per contour ( points per slice)

Fenwick, et al IJROBP 49473480, 2001
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Randomized Trials

• Of higher dose vs. lower dose?

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PROG 9509

• Trial design
• No hormonal therapy

T1b-2b prostate cancer PSA lt15ng/ml
r a n d o m i z a t i o n
Proton boost 19.8 GyE
Proton boost 28.8GyE
3-D conformal photons 50.4 Gy
3-D conformal photons 50.4 Gy
Total prostate dose 79.2 GyE
Total prostate dose 70.2 GyE
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Zietman, et al. JAMA20052941233-1239
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Morbidity?
Zietman, et al. JAMA20052941233-1239
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• Dutch Study Points
• ASTRO no backdating
• 21 had hormonal rx
• 0 mm post PTV marginfrom 68-78 Gy
• Dose prescribed toisocenter

Peeters et al. JCO 241990,2006
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Randomized Trials

• Of altered fractionation vs. standard
  fractionation?

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Hypofractionation
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Hypofractionated Randomized Trial

• 16 Canadian regional centres
• 66 Gy in 33 fx vs. 52.5 Gy in 20 fx (2.62)
• Simple conformal rx
• Non-inferiority design with abs diff 7.5

Lukka, et al. JCO 236132,2005
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7 worse in short arm
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RTOG 0415 Schema
73.8 Gy/41 Fx
T1c-2a GS lt7 PSA lt10
70 Gy/28 Fx
n800 Endpoint is 5 Year BFFF Non-inferiority
margin 7 (Control 85, Exp 78)
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Other Hypofractionation Randomized Trials

• CHHIP (Conv or Hypo High Dose IMRT)
• N2200
• 3 arm study
• Standard vs. 2 hypofractionated arms

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Randomized Trials

• Particle vs. photon?
• No PSA era trials
• MGH proton, RTOG neutron

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Particle Therapy

• Protons
• Bragg peak
• Concerns
• Wide penumbra due to scattering
• Neutron dose unless proton IMRT (scanned beam) is
  used (from p,n reaction)

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Carbon Ion

• Higher LET - ?Better for more resistant tumors
• ?Fewer fractions needed
• The promising results obtained with carbon
  radiotherapy need confirmation in controlled
  clinical trials with large patient numbers
  comparing carbon ion RT with photon IMRT and
  proton RT taking also into account toxicity and
  quality of life.
• Schulz-Ertner, et al Radiation Therapy With
  Charged Particles Semin Radiat Oncol 16249,2006

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Future Technologies/Areas for Study

• Particle therapy
• Carbon vs. Proton vs. Photon IMRT
• Hypofractionation
• Can the low a/ß model for prostate be verified?
• NTCP modelling
• Randomized trials can help
• Target motion
• Issue for all externally delivered, highly
  conformal dose approaches