Lack of accrual

This study is being done to test the safety of a single high-dose of radiation therapy before radical prostatectomy (removal of the prostate). The investigators want to find out what effects, good and/or bad, the radiation will have on men undergoing prostatectomy. The investigators are especially interested in men who are at risk for having cancer cells that have spread outside the prostate.

Inclusion Criteria:

• Biopsy-proven prostate cancer verified at MSKCC. The biopsy will include a minimum of 10 cores
• Radical Prostatectomy (RP) chosen as the therapeutic method
• The size of the prostate will be < 70 cc by transrectal ultrasound or endorectal MRI imaging
• No radiographic evidence of lymph node metastases, bone metastases or soft tissue disease
• Risk of extraprostatic cancer of > 40% based on the MSKCC surgical nomogram
• Age > or = to 18 years
• KPS > or = to 80
• Able to tolerate immobilization cradle positioning

Exclusion Criteria:

• Allergic reaction to intravenous CT contrast (if premedicated, pt will not be excluded)
• Prior radiation to the planned target region
• Patients receiving concurrent chemotherapy
• Neoadjuvant hormonal therapy Luteinizing-hormone-releasing hormone(LHRH)agonist and/or antiandrogen)
• Prior transurethral resection of the prostate
• Normal tissue directly overlying target precluding ability to limit the bowel, bladder, rectum or other tissue to less than or equal to 15-16 Gy dose constraints
• Dominant prostatic lesion within 3 mm from the anterior rectal wall by imaging studies
• Creatinine clearance <60 ml/min/1.73m2