Highly Conformal, Hypofractionated, Focally Dose Escalated Post-Prostatectomy Radiotherapy

BACKGROUND: Prostate cancer that recurs after prostatectomy (rising prostate-specific antigen (PSA) with no evidence of metastatic disease is often treated with radiation to the entire prostate bed to a dose of 66-72 Gray (Gy) over 6-7 weeks. This treatment can provide PSA control in approximately 75% of patients but may have associated genitourinary and gastrointestinal toxicity due to irradiation of the rectum, small bowel, and bladder. Imaging of prostate cancer has improved to the extent that recurrent disease is often identified in the prostate bed or in other pelvic sites. The current standard is to irradiate the entire prostate bed to the total dose. This trial will test the tolerability of accelerated treatment designed to yield a similar rate of late toxicity. In addition, in patients with visible tumor, it will test the feasibility of delivering a lower dose to the prostate bed and an integrated boost (simultaneous) to the visible tumor to allow a higher dose to visible tumor than can be delivered with standard approaches. OBJECTIVE: \- Define the maximum tolerated dose (MTD) hypofractionation of image guided, focally dose escalated post-prostatectomy radiation. ELIGIBILITY: * PSA recurrence after prostatectomy or indications for adjuvant radiation after prostatectomy. * No evidence of distant metastases of prostate cancer (pelvic lymph nodes are allowed). * Age greater than or equal to 18 years old * Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1 DESIGN: This is a Phase I trial of hypofractionated focal dose escalation with reduced dose prostate bed irradiation using image and pathologic guidance. The prostate bed will be treated with hypofractionated radiation and areas in the prostate bed or pelvis shown to have tumor on biopsy or with advanced imaging studies will be treated with an integrated boost to visible tumor. The treatment duration will be decreased sequentially in three Dose Level groups. Quality of life and functional outcomes such as urine, bowel, and erectile function will be assessed with questionnaires. A maximum of 48 patients will be enrolled.