Radiation Therapy in Treating Patients With Stage I or Stage II Prostate Cancer

OBJECTIVES: I. Determine whether high-dose radiotherapy using conformal photons with a proton boost produces a 20% increase in the proportion of Stage I/II prostate cancer free from local failure and biochemical relapse at 5 years when compared to results of conventional-dose radiotherapy. II. Determine whether high-dose radiotherapy produces a 33% reduction in the cumulative incidence of a rising PSA (second hormone failure) following hormone therapy given at the time of first PSA/clinical failure when compared with conventional-dose radiotherapy. IV. Assess the relative rectal, bladder, and sexual morbidity of conformal photon doses of 70.2 and 79.2 Gy in these patients. V. Collect, in a prospective manner, paraffin biopsy blocks for subsequent analysis of emerging molecular pathologic predictors of outcome in three patients. OUTLINE: Randomized study. Arm I: Radiotherapy. Boost to the prostate using high-LET protons followed by irradiation of the prostate, periprostatic tissues, and seminal vesicles using conformal photons with energies greater than 6 MV. Conventional dose. Arm II: Radiotherapy. As in Arm I. High dose. PROJECTED ACCRUAL: There will be 390 patients accrued into this study over 3 years. An additional 3.5 years will be required for follow-up.