Pelvic Breakout Group

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Pelvic Breakout Group
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Purpose of meeting

• What is current status of radiation oncology
  technologies today.
• Where should we invest research resources to best
  understand value of technology
• Biology questions can be addressed parallel to
  technology usage
• Preop rectumexamine tissue effects
• IMRT low doses
• QA, training, educationis required to optimally
  implement new technology
• Clinical trials are necessary to evaluate
  technology

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KEY QUESTION 1

• The raison detre for the advanced technologies
  is to increase the dose to the cancer without
  increasing toxicity, or deliver the same dose as
  conventional technology but with less toxicity.
• QUESTION In which cancers is there the most
  pressing need for new technology for increasing
  the dose or decreasing the toxicity?

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KEY QUESTION 1

• The raison detre for the advanced technologies
  is to accurately target and improve our
  understanding when we increase the dose to the
  cancer without increasing toxicity, or deliver
  the same dose as conventional technology but with
  less toxicity.
• QUESTION In which cancers is there the most
  pressing need for new technology for increasing
  the dose or decreasing the toxicity?

Targeting is just as important as dose. If you
give high doses but miss, you have failed
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In which cancers is there the most pressing need
for new technology for increasing the dose or
decreasing the toxicity?

• Prostateremains an important public health
  problem. Dose matters but is gt80Gy necessary?
• Postop prostatewhat is the CTV?
• Nodal target volumes are important in all pelvic
  malignancies. What is best way to define (PET,
  MR-LG, RaAb)
• Cervixwhat is the CTV?
• MR guided brachytherapy
• Rectal CancerIMRT for short course RT 5x5Gy

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In which cancers is there the most pressing need
for new technology for increasing the dose or
decreasing the toxicity?

• Prostate
• Important public health problem
• Local control remains problematic
• Dose escalation to Subclinical disease
• Rectum
• Dose to small bowel
• Interactions of systemic therapy and XRT
• Biomarkers and interaction with XRT
• Cervix
• Opportunity for adaptive (change plan) RT
• Interactions of systemic therapy and XRT
• Dose to small bowel
• What is the CTV for primary and nodal drainage
• PET, MR-LG, Labeled antibodies, etc

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In which cancers is there the most pressing need
for new technology for increasing the dose or
decreasing the toxicity?

• Should we dose escalate subclinical disease?
  e.g. 75Gy to the PAN
• What about the role of systemic therapy when we
  intensify local therapy?
• Biomarkers and their interactions with radiation
  therapytailored dose escalation
• Cervix, rectum, prostate
• Cervix an opportunity for adaptive radiation
  therapy trial (image guidance)
• Change plan to eliminate brachytherapy (response
  based)?

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KEY QUESTION 2

• Demonstrating improved ANTICIPATED dose
  distributions (in-silico or in phantoms) only
  generates the hypothesis that a new technology
  may be superior. To prove that hypothesis, we
  must demonstrate - by controlled clinical trials
  - a clinically meaningful increase in survival
  and/or decrease in toxicity.
• QUESTION What clinical trials are the most
  important for demonstrating a meaningful benefit
  to patients?

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What clinical trials are the most important for
demonstrating a meaningful benefit to patients?

• Prostatephase III trial with QOL endpoints
• Might be too soon to study, once organ motion and
  delivery uncertainties are resolvedif RadOnc
  community demands it.
• Prostate High riskphase II trial
• Nodal RT (IMRT) and further dose escalation HT
• Rectumphase II trials
• Biological endpoints
• QOL
• CervixPhase I/II trials
• Biological correlates
• QOL

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What clinical trials are the most important for
demonstrating a meaningful benefit to patients?

• Fractionation opportunities in all sites
• QOL should be allowed as a primary endpoint in
  phase III trials

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KEY QUESTION 3

• Demonstrating improved ACTUAL dose distribution
  in the patient could be useful in phase I/II
  trials.
• QUESTION What technological developments are
  required for demonstrating ACTUAL dose
  distribution in-vivo?

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What technological developments are required for
demonstrating ACTUAL dose distribution in-vivo?

• Dose modeling (with validated calculation
  methods)
• Exit fluence
• Deformation
• Tracking of accumulated dose
• Activated PET measures
• Implanted dosimeters
• Elimination of systematic errorcan this be
  studied in a clinical trial

Cannot underestimate need to verify dose
delivery20 rule!
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KEY QUESTION 4

• Other clinical or biological intermediate
  end-points may be useful in clinical trials.
• QUESTION What might those intermediate
  end-points be (and what lessons have we learned
  regarding their pitfalls from PSA, etc?)

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What might those intermediate end-points be (and
what lessons have we learned regarding their
pitfalls from PSA, etc?)

• PSA Phoenix/ASTRO definition
• Pathologic CR in rectal cancer
• PET imaging for rectum, cervix
• FLT, F-Miso during XRT
• FDG pre and post XRT
• MRS for cervix
• MRI/MRS post RT for Prostate
• Serum and fresh tissue banking
• Genomics, Proteomics