This research study is being done to develop a new test to identify prostate cancer patients at highest risk of radiotherapy-related complications. This research study would allow monitoring of total tissue damage within 24 hours of radiation exposure in blood samples that could give an initial result within a few days that would help clinicians make treatment decisions. Detection of unusual tissue damage at this early time, well before symptoms occur, could allow doctors to tailor interventions that could include patient therapies that would reduce or prevent the problems that occur due to treatment of their cancer.

Currently, a patient's risk for toxicity is based almost exclusively on population statistics. Radiation (and chemotherapy) dose are based on phase I data and not on the individual's specific genetics or hidden predispositions. RadTox measures cell damage within 24 hours of radiation exposure and should help identify patients at higher risk for radiation complications. This should allow physicians to adjust radiation field size and dose to minimize long-term toxicity.

Patients undergoing radiation treatment for stage I to III prostate cancer, using protons or X-rays, either as primary treatment or consolidation after prostatectomy (positive margins or prostate-specific assay [PSA]-related indications) will be eligible. Hormone treatment will be allowed.

Inclusion Criteria:

• Consent to participate in the study and a signed and dated an institutional review board (IRB)-approved consent form conforming to federal and institutional guidelines.
• ≥ 18 years of age.
• Patients must have an Eastern Cooperative Oncology Group (An ECOG) performance status of 0 or 1.
• A diagnosis of adenocarcinoma of the prostate.
• Not yet begun definitive therapy with chemotherapy or radiation but may have hormones or surgery.
• Clinically stage I to III tumors.

Exclusion Criteria:

• Metastatic disease.
• A history of invasive rectal malignancy or other pelvic malignancy, regardless of disease-free interval.
• Active inflammatory bowel disease (i.e., patients requiring current medical interventions or who are symptomatic).
• Prior pelvic radiation therapy for any reason.
• Psychiatric or addictive disorders or other conditions that, in the opinion of the principal investigator (PI), would preclude the patient from meeting the study requirements.

Male patients with undergoing radiation therapy for prostate cancer

Data will be shared with necessary government agencies, the sponsor, and participating providers and institutions as defined in the informed consent document.