RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. It is not yet known whether standard radiation therapy is more effective than high-dose radiation therapy in treating patients with prostate cancer.

PURPOSE: Randomized phase III trial to compare the effectiveness of standard radiation therapy with that of high-dose radiation therapy in treating patients with stage II or stage III prostate cancer.

OBJECTIVES:

• Compare local tumor control in patients with stage II or III prostate cancer treated with neoadjuvant androgen deprivation therapy with standard vs high-dose conformal radiotherapy.
• Compare the incidence of biochemical failure (prostate-specific antigen (PSA) greater than 2 ng/mL at 6 or more months after initiation of radiotherapy and PSA rising from nadir level by at least 50%), development of metastases, and survival in patients treated with these regimens.
• Compare the acute and late radiation-induced side effects of these regimens in this patient population.
• Compare aspects of quality of life, health economics, models of normal tissue, and tumor control in patients treated with these regimens.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to prostate-specific antigen, T stage, and Gleason score. Patients are randomized to one of two treatment arms.

All patients receive neoadjuvant androgen deprivation with luteinizing hormone-releasing hormone agonists every 4 weeks beginning 3-6 months before initiation of radiotherapy and continuing until completion of radiotherapy.

• Arm I: Patients undergo standard conformal radiotherapy for 6.5 weeks.
• Arm II: Patients undergo high-dose conformal radiotherapy for 7.5 weeks. Quality of life is assessed at baseline, every 6 months for 2 years, and then annually thereafter.

Patients are followed every 6 months for 2 years and then annually thereafter.

PROJECTED ACCRUAL: A total of 800 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed prostate cancer

  • T1b-T3a, N0, M0 (stage II or III)

• Prostate-specific antigen at least 50 ng/mL

PATIENT CHARACTERISTICS:

Age:

• Not specified

Performance status:

• WHO 0-1

Life expectancy:

• Not specified

Hematopoietic:

• WBC greater than 4,000/mm^3
• Platelet count greater than 100,000/mm^3
• Hemoglobin greater than 11 g/dL

Hepatic:

• Not specified

Renal:

• Not specified

Other:

• No significant past medical history that would preclude radical radiotherapy
• No condition that would preclude standard radiotherapy
• No hip prosthesis

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• Not specified

Endocrine therapy:

• No prior androgen deprivation therapy

Radiotherapy:

• No prior pelvic radiotherapy

Surgery:

• No prior radical prostatectomy