Feasibility and Safety Study Using Preoperative High-Dose Single-Fraction Image-Guided Radiotherapy for Men Undergoing Radical Prostatectomy at High-Risk for Extraprostatic Cancer

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