Daily Adaptive Post-Prostatectomy With Stereotactic Ablative Radiotherapy in Patients With Prostate Cancer

This clinical trial evaluates the feasibility, safety, and tolerability of stereotactic ablative radiotherapy (SABR) using daily adaptive radiation techniques to the prostate fossa and/or pelvic lymph nodes in patients with prostate cancer who have undergone surgical removal of the prostate (radical prostatectomy). For patients with prostate cancer who develop a rising prostate specific antigen (PSA) after radical prostatectomy, salvage radiation therapy is the standard of care treatment. Radiation therapy uses high energy x-rays to kill tumor cells and shrink tumors. All patients receiving salvage radiation following radical prostatectomy typically have treatment directed to the prostate fossa, which is the anatomical region around the operative bed that is at highest risk for containing left over tumor. Many patients receiving salvage radiation therapy can also benefit from treatment of the pelvic lymph nodes. Adaptive radiotherapy is an emerging treatment technique that uses daily imaging to adjust treatment volumes, ensure accurate dose delivery, and allow the use of smaller planning target volume margins. Adaptive radiation is ideally suited for the further implementation of SABR treatment regimens directed to the prostate fossa with or without inclusion of the pelvic lymph nodes. While daily adaptive radiation therapy has been reported in other disease settings, there is currently no data about its use for post-prostatectomy radiation. Using daily adaptive radiation techniques may help researchers learn how to minimize exposure to normal tissue and shorten the number of required treatments to better target the radiation dose in prostate cancer patients post-prostatectomy.

PRIMARY OBJECTIVE:

I. To demonstrate the safety of daily, adaptive online replanning in patients treated with stereotactic body radiation therapy (SBRT) to the prostate +/- pelvic lymph nodes as defined by observation of a grade 3 genitourinary and gastrointestinal toxicity rate of less than or equal to 5%.

SECONDARY OBJECTIVES:

I. To determine the feasibility of daily, adaptive online replanning for patients receiving SBRT to the prostate fossa +/- pelvic lymph nodes.

II. To assess the efficacy of daily, adaptive SBRT to the prostate fossa. III. To measure the change in patient reported urinary, bowel, and sexual outcomes following protocol treatment.

EXPLORATORY OBJECTIVE:

I. To assess the dosimetric benefits of daily adaptive replanning for prostate fossa/pelvic lymph node SBRT.

OUTLINE: Patients are assigned to 1 of 2 groups.

GROUP I: Patients undergo daily adaptive online replanning for SBRT to the prostate fossa on study. Patients also undergo (MRI) of the prostate fossa and pelvis and may undergo positron emission tomography/computed tomography (PET/CT) during screening.

GROUP II: Patients undergo daily adaptive online replanning for SBRT to the prostate fossa and pelvic lymph nodes on study. Patients also undergo MRI of the prostate fossa and pelvis and may undergo PET/CT during screening.

Eligibility Criteria:
Inclusion Criteria:

* Males age \>= 18 years who are receiving post-operative radiation therapy to the prostate fossa, with or without inclusion of the pelvic lymph nodes, for biochemical recurrences after radical prostatectomy.
* Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) =\< 2.
* Ability to complete questionnaire(s) by themselves or with assistance.
* Provide written informed consent.
* Willingness and ability to complete protocol-specified follow-up (during the active monitoring phase of the study).

Exclusion Criteria:

* Current evidence of untreated metastatic prostate cancer involving nonregional lymph nodes outside of the bony pelvis, bone, or visceral organs.
* Receipt of cytotoxic chemotherapy within 3 months prior to enrollment.
* Prior radiation therapy to pelvis such that the proposed study treatment volume received 10 Gy or greater.
* Co-morbid severe concurrent disease that would result in a life expectancy of \< 5 years.
* Diabetes mellitus-associated vascular ulcers or wounding healing problems, inflammatory bowel disease, or a diagnosed connective tissue disorder.
* Medical or psychiatric conditions that preclude informed decision-making or adherence to study protocols.
* Men of childbearing potential who are unwilling to employ adequate contraception.
* History of a bladder neck contracture, urethral stricture that required dilation, or any surgical repair/reconstruction involving the bladder or urethra other than radical prostatectomy.