Abstract |
Proton therapy confers substantially lower predicted risk of second cancer compared with photon therapy. However, no previous studies have used an algorithmic approach to optimize beam angle or fluence-modulation for proton therapy to minimize those risks. The objectives of this study were to demonstrate the feasibility of risk-optimized proton therapy and to determine the combination of beam angles and fluence weights that minimizes the risk of second cancer in the bladder and rectum for a prostate cancer patient. We used 6 risk models to predict excess relative risk of second cancer. Treatment planning utilized a combination of a commercial treatment planning system and an in-house risk-optimization algorithm. When normal-tissue dose constraints were incorporated in treatment planning, the risk model that incorporated the effects of fractionation, initiation, inactivation, repopulation and promotion selected a combination of anterior and lateral beams, which lowered the relative risk by 21% for the bladder and 30% for the rectum compared to the lateral-opposed beam arrangement. Other results were found for other risk models.
|
Authors | Laura A Rechner, John G Eley, Rebecca M Howell, Rui Zhang, Dragan Mirkovic, Wayne D Newhauser |
Journal | Physics in medicine and biology
(Phys Med Biol)
Vol. 60
Issue 10
Pg. 3999-4013
(May 21 2015)
ISSN: 1361-6560 [Electronic] England |
PMID | 25919133
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.)
|
Topics |
- Algorithms
- Dose Fractionation, Radiation
- Humans
- Male
- Middle Aged
- Neoplasms, Radiation-Induced
(prevention & control)
- Prostatic Neoplasms
(radiotherapy)
- Proton Therapy
(adverse effects, methods)
- Radiotherapy Planning, Computer-Assisted
(methods)
- Risk
|