Inclusion Criteria:

1. Adenocarcinoma of the prostate treated primarily with radical prostatectomy,
pathologically proven to be lymph node negative by pelvic lymphadenectomy (N0) or
lymph node status pathologically unknown (undissected pelvic lymph nodes [Nx]), i.e.
lymph node dissection is not required;

2. Any type of radical prostatectomy will be permitted, including retropubic, perineal
laparoscopic or robotically assisted. If performed, the number of lymph nodes removed
per side of the pelvis and the extent of the pelvic lymph node dissection (obturator
vs. extended lymph node dissection) should be noted. There is no time limit for the
date of radical prostatectomy.

3. A post-radical prostatectomy entry PSA of > 0 and < 1 ng/ml at least 6 weeks after
prostatectomy and within 30 days of registration.

4. One of the following pathologic/chemical classifications:

- T3N0/Nx disease with or without positive surgical margin; or;

- Gleason score of 8 or more;

- Pre prostatectomy PSA > 20 ng/ml

5. KPS > 70

6. Age ≥ 18;

7. No distant metastases, based upon the following minimum diagnostic workup:

8. History/physical examination (including digital rectal exam) within 8 wks prior to
registration;

9. A CT scan or MRI of the abdomen and pelvis within 120 days prior to registration;

10. Bone scan within 120 days prior to registration; if the bone scan is suspicious, a
plain x-ray and/or MRI must be obtained to rule out metastasis.

11. Adequate bone marrow function, within 90 days prior to registration, defined as
follows:

- Platelets ≥ 100,000 cells/mm3 based upon CBC;

- Hemoglobin ≥ 10.0 g/dl based upon CBC

- AST or ALT < 2 x the upper limit of normal within 90 days prior to registration;

12. Patients must sign a study-specific informed consent prior to study entry.

EXCLUSION CRITERIA:

1. A palpable prostatic fossa abnormality/mass suggestive of recurrence, unless shown by
biopsy under ultrasound guidance not to contain cancer;

2. N1 patients are ineligible, as are those with pelvic lymph node enlargement ≥ 1.5 cm
in greatest dimension by CT scan or MRI of the pelvis, unless the enlarged lymph
node is sampled and is negative;

3. Androgen deprivation therapy started prior to prostatectomy for > 6 months duration;

4. Androgen deprivation therapy started after prostatectomy and prior to registration;

5. Prior pelvic radiotherapy;

6. Prior invasive malignancy (except non-melanomatous skin cancer) unless disease free
for a minimum of 5 years (for example, carcinoma in situ of the oral cavity is
permissible);

7. Severe, active co-morbidity, defined as follows:

- History of inflammatory bowel disease;

- History of hepatitis B or C; Blood tests are not required to determine if the
patient has had hepatitis B or C, unless the patient reports a history of
hepatitis.

- Unstable angina and/or congestive heart failure requiring hospitalization
within the last 6 months;

- Transmural myocardial infarction within the last 6 months

- Acute bacterial or fungal infection requiring intravenous antibiotics at the
time of registration;

- Chronic Obstructive Pulmonary Disease exacerbation or other respiratory illness
requiring hospitalization or precluding study therapy at the time of
registration;

- Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects;
AST or ALT are required; note, however, that laboratory tests for coagulation
parameters are not required for entry into this protocol.

- Prior allergic reaction to the study drug(s) involved in this protocol.