RATIONALE: Androgens can cause the growth of prostate cancer cells. Antihormone therapy, such as leuprolide and bicalutamide, may lessen the amount of androgens made by the body. Implant radiation therapy kills tumor cells by placing material such as radioactive iodine directly into or near a tumor. Giving leuprolide and bicalutamide together with implant radiation therapy may kill more tumor cells.

PURPOSE: This phase II trial is studying the side effects of giving leuprolide and bicalutamide together with implant radiation therapy and to see how well it works in treating patients with locally recurrent prostate cancer after external-beam radiation therapy.

OBJECTIVES:

• Determine the feasibility and patient tolerance of interstitial brachytherapy combined with androgen-deprivation therapy for patients with locally recurrent prostate cancer after prior external-beam irradiation.
• Determine the toxicity of interstitial brachytherapy combined with androgen-deprivation therapy in these patients.
• Determine the tumor response to interstitial brachytherapy combined with androgen-deprivation therapy in these patients.

OUTLINE: Patients receive neoadjuvant therapy comprising leuprolide acetate intramuscularly for 3 months and oral bicalutamide once daily for 30 days, beginning on the first day of leuprolide acetate administration. Patients then undergo interstitial brachytherapy implantation with I-125. Following brachytherapy, patients receive adjuvant leuprolide acetate every 3 months for an additional 6 months.

Quality of life is assessed at baseline and at every treatment and follow-up visit.

After completion of study therapy, patients are followed every 3 months for 2 years, every to 4-6 months for 3 years, and then annually thereafter.

DISEASE CHARACTERISTICS:

• Biopsy-proven adenocarcinoma of the prostate

  • Locally recurrent disease, defined by digital rectal examination and/or rising prostate-specific antigen (PSA)

• No evidence of nodal or distant metastasis (i.e., N0, M0) on physical examination, bone scan, or CT scan of the pelvis

• Clinical stage T1c-T3a disease at the time of recurrence

• PSA < 10 ng/mL

• Prostate volume by transrectal ultrasonography < 60 cc

• Received prior external beam radiotherapy

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• WBC ≥ 3,000/μL
• Platelet count ≥ 90,000/μL
• Hemoglobin ≥ 10 g/dL
• Alkaline phosphatase < 2 times normal
• AST < 2 times normal
• Normal prothrombin time and partial thromboplastin time
• No significant obstructive urinary symptoms (AUA score ≤ 16)
• No contraindication for general anesthesia

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior transurethral resection of the prostate