Conditions for Patient Eligibility:

* The patient on entry will have no clinical evidence of disease by physical exam or by imaging studies. A positive ProstaScint scan alone without a confirmatory biopsy must not be used to exclude a patient. Eligible patients will be those who have undergone a radical prostatectomy (either retropubic or perineal) and pelvic lymphadenectomy (either open or laparoscopic) for carcinoma of the prostate, pathologic stage T3N0, or pT2 pN0 with positive inked resection margin, at least 12 weeks prior to study entry.
* Pathological T2 patients without positive margins, who are also pathologic N0 with prostatic fossa/anastamosis biopsy at the time of rising PSA documenting recurrent cancer, are eligible.
* At entry, the PSA must be between 0.2 and 4.0ng/ml, inclusive.
* A post-prostatectomy radioisotopic bone scan which was done within 16 weeks prior to entry must reveal no evidence of metastatic disease.
* Patient must be evaluated by both the radiation oncologist and the urologist prior to entry and judged to be a suitable candidate for radiation and hormonal therapy.
* Patient must have Karnofsky performance status >= 80.
* Patients must have a life expectancy in excess of 10 years.
* Patients must have, within 6 weeks prior to entry, a hemoglobin (Hgb) of >=10 gm, a white blood cell (WBC) count of >= 4000 cells/ml3, a platelet count of >= 100,000 cells/ml3, a serum bilirubin <= the institutional upper limit of normal, a serum serum glutamic-oxaloacetic transaminase (SGOT) or serum glutamic-pyruvic transaminase (SGPT) of <= 2.5 times the institutional upper limit of normal, and a serum creatinine of <= 2.0 times the institutional upper limit of normal.
* A post-prostatectomy pelvic computerized tomography (CT) scan, within 16 weeks prior to randomization, must reveal no evidence of metastatic disease.
* Patients must sign a study-specific informed consent form.
* Patients with prior invasive cancers are eligible if disease free for at least 5 years; prior or concurrent basal or squamous cell skin cancer is eligible.

Conditions for Patient Ineligibility:

* Pathologic stage T2 (without positive inked resection margin) or less except as stated in Section 3.1.1.1.
* Pathologic lymph node stage of pN1 or greater.
* An entry serum PSA of > 4.0ng/ml.
* Patients with persistant urinary extravasation after prostatectomy.
* Patients who have been previously treated with any hormonal therapy after prostatectomy.
* Patients who have previously been treated with radiation therapy or biologic therapy for prostate cancer.
* Karnofsky performance status < 80.
* Treatment start > 4 weeks after randomization.
* Prior chemotherapy for any reason.