DISEASE CHARACTERISTICS: Histologically or cytologically proven carcinoma of the prostate that has relapsed subsequent to chemical or surgical castration and/or antiandrogen therapy Painful, unirradiated osseous metastasis required Documentation by bone scan and x-ray required Number and extent of metastases determined according to Soloway and fitting grades 1-3 Prior hormonal therapy must have lasted at least 3 months and must be continued until completion of this study No imminent paraplegia related to metastases No uncorrectable urinary incontinence

PATIENT CHARACTERISTICS: Age: Any age Performance status: WHO 0-2 Hematopoietic: WBC greater than 3,500 Platelets greater than 150,000 Hepatic: Not specified Renal: Creatinine no greater than 2.2 mg/dl (200 micromoles/liter) Other: No calcium supplementation No second malignancy except basal cell skin cancer

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No restriction Endocrine therapy: Prior and concurrent hormonal therapy required Radiotherapy: No prior strontium-89 No prior hemibody or total-body irradiation Prior local-field irradiation for bone metastases allowed provided new site of painful metastases exists Surgery: Surgical castration allowed