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

OBJECTIVES: I. Determine the maximum tolerated dose of 3-dimensional conformal radiotherapy to the prostate gland and immediately surrounding tissues in patients with stage II or III adenocarcinoma of the prostate. II. Determine the normal tissue toxicity rate of this regimen in the rectums and bladders of these patients. III. Determine local control by clinical and pathologic examination and by PSA determinations in patients treated with this regimen. IV. Determine the distant failure and overall survival of patients treated with this regimen. OUTLINE: This is a dose escalation study. Patients are stratified according to 1 of the following 3 prognostic groups: Group 1: T1b-c or T2a-b with combined PSA/Gleason (CPG) score 15 and under Group 2: T1b-c or T2a-b with CPG score more than 15, or any T2c with PSA less than 70 ng/mL Group 3: T3 with prostate specific antigen (PSA) less than 70 ng/mL Patients receive 3-dimensional (3-D) conformal radiotherapy 5 days a week for 7.6, 8.2, or 8.8 weeks. Cohorts of 120-270 patients receive escalating doses of 3-D conformal radiotherapy until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 20% of patients experience dose-limiting toxicity. Patients are followed every 3 months for 1 year, every 4 months for 1 year, every 6 months for 3 years, and then annually thereafter. PROJECTED ACCRUAL: A total of 549-801 patients (120-204 patients for the first dose level, 237-321 patients for the second dose level, and 192-276 patients for the third dose level) will be accrued for this study within 4.75 to 5.25 years.