This is a Phase I dose-escalation study of moderate dose radiation therapy prior to radical prostatectomy for patients with high-risk localized disease. Its hypothesis is that such treatment will be well tolerated with similar side effect profile as surgery alone. Patients in Groups 1 and 2 will receive 39.6 Gy and 45 Gy (at 1.8 Gy/fx), respectively, to the whole pelvis. Patients in Groups 3 and 4 will receive 45 Gy to the whole pelvis, followed by a boost to the prostate and periprostatic tissue, for total doses of 50.4 and 54 Gy, respectively. The patient will then undergo radical prostatectomy between 4-8 weeks after completion of radiation.

Inclusion Criteria:

Subjects must have

• biopsy-confirmed "high-risk" prostate cancer, defined as A. PSA > 20, B. Gleason Score (GS) >/= 8, and/or C. Clinical stage T3 disease per AJCC Staging Manual, 6th edition; or D. At least two out of three of the following: PSA 10-19.9, GS = 7, or clinical stage = T2b / T2c.
• a negative bone scan,
• be medically fit to undergo surgery as determined by treating urologist,
• age > 18,
• KPS must be >/= 80,
• no prior pelvic radiation therapy, chemotherapy, or androgen deprivation,
• no prior invasive malignancy, except non- melanomatous skin cancer unless disease free for a minimum of 5 years. Carcinoma in-situ of the bladder or head and neck region is permissible.
• Subjects must freely sign informed consent to enroll in the study.

Exclusion Criteria:

• prior pelvic radiation therapy, chemotherapy, or androgen deprivation,
• prior invasive malignancy, except non- melanomatous skin cancer, carcinoma in-situ of the bladder or head and neck region, unless disease free for a minimum of 5 years.
• Metastatic disease as demonstrated by bone scan, CT scan or MRI of the pelvis, or chest x-ray.
• Pathologically documented positive pelvic lymph nodes. If Pre-operative CT scan or MRI (ordered at the discretion of the treating physicians) demonstrates lymph nodes which are suspicious for involvement, then biopsy must be undertaken and nodes proven negative before patient can enroll on this trial.
• Declared high-risk for anesthesia by attending anesthesiologist, cardiologist, or other physician.
• History of prior pelvic radiation therapy.
• History of androgen deprivation therapy or chemotherapy.