2002 CTOS Annual Meeting Oral Presentations — Radiation Oncology

ADVANTAGES OF PROTON BEAMS IN TREATMENT PELVIC SARCOMAS
[Abstract ID: 76]

Category: Radiation Oncology

Presentation: Oral

Authors: Herman Suit¹, Thomas Bortfeld¹, Andrzej Niemierko¹, Alexei Trofimov¹, Thomas DeLaney¹

Author Institutions: ¹Massachusetts General Hospital, Massachusetts, United States

Presenter: Herman Suit
Email: hsuit@partners.org

Correspondent: Herman Suit
hsuit@partners.org
Boston Massachusetts United States 02114
Ph: 617 724 1155
Fax: 617 726 4805

Objectives: To assess the clinical gains predicted by use of proton beams rather than the highest technology photon beams in the radiation treatment of sarcomas of the pelvis.

Methods: Complete treatment plans based on intensity modulated proton and photon methods for sarcomas at the sacrum, pubic bone/symphysis and inguinal soft tissues. The treatment plans are to account for heterogeneities in tissue densities, motion of the target and critical normal tissues during and between treatment sessions. The comparison of the treatment plans will be based upon calculated complication probabilities for the critical normal tissues for the different plans. Estimates of the maximum dose for each plan for a Grade IV complication probability of 1, 3 and 5% will be presented. Estimates will be presented of the tumor control probability for each plan for the three levels of complication probability.

Results: The major predicted clinical gains for each of the three sites are: Site 1 sacrum, virtually no dose to the intestinal track; Site 2 pubic bone/symphysis - virtually no dose to the urinary bladder and Site 3 inguinal regional, virtually no dose to femoral head/neck. Theresult is marked reduction to treatment related morbidity at those normal tissues. The markedly lower doses to the intestinal tract and bladder will offer the addition gain of higher chemotherapy doses. The final calculated probabilities will be presented in November.

Conclusions: For radiation treatment of sarcomas of these three anatomic sites, proton beam technology is predicted to yield a higher proportion of patients who are rendered tumor and complication free.