RATIONALE: Radiation therapy uses high-energy x-rays and other types of radiation to kill tumor cells and shrink tumors. Androgens can cause the growth of prostate cancer cells. Androgen-deprivation therapy may lessen the amount of androgens made by the body. It is not yet known whether radiation therapy is more effective with or without androgen-deprivation therapy in treating patients with prostate cancer.
PURPOSE: This randomized phase III trial is studying radiation therapy to see how well it works compared with radiation therapy given together with androgen-deprivation therapy in treating patients with prostate cancer.