Prospective Observational Exploratory Clinical Study to Determine the Assay Cut-Off for the RadTox Test in Prostate Cancer Patients to Predict Gastrointestinal Radiation Toxicity Using Circulating Cell Free DNA Directly From Plasma

Inclusion Criteria:

• Men diagnosed with adenocarcinoma of the prostate who have not received previoustreatment (defined as prostatectomy, transurethral resection of the prostate [TURP],radiation of the pelvis, and GreenLight Laser Therapy) except for short-term (≤6months) Androgen Deprivation Therapy (ADT) according to National Comprehensive CancerNetwork (NCCN) guidelines.
• Candidate for definitive prostate radiotherapy (either IMRT or proton).
• Patients to be treated with IMRT should have all radiation treatment planned withIMRT, whereas patients to be treated with protons should have all radiation treatmentplanned with protons (including pelvic nodes if treated).
• Localized prostate cancer, as confirmed by staging with Prostate-Specific Antigen (PSA), biopsy, Gleason score, and clinical stage.
• Nuclear medicine bone imaging is required for confirmation of the absence of overtmetastatic disease in bones if any high-risk criteria are identified (clinical stageT3a or higher; or 1-4 cores of Gleason score 8 [NCCN Grade Group 4] or 4+5; or PSA ≥20ng/mL).
• Diagnosed with any of the NCCN initial groups (i.e., Very-Low-Risk, Low-Risk,Intermediate-Risk [both Favorable and Non-Favorable Intermediate-Risk]; High-Risk; orVery-High-Risk) (see Appendix III for NCCN classifications of various risk groups).For Very-High-Risk, subjects are to have negative prostate cancer specific PET/CTimaging for confirmation of being metastasis free.
• The score for Question 16 (i.e., "Overall, how big a problem have your bowel habitsbeen for you during the last 4 weeks?") of the Bowel Habits section of ExpandedProstate Cancer Index Composite (EPIC) questionnaire must be 2 or below.
• 30-85 years of age at the time of consent.
• Eastern Cooperative Oncology Group (ECOG)/Zubrod Performance Status 0 - 2.

Exclusion Criteria:

• Findings of metastatic disease (nodal or distant, >N1 or M1).
• Prior prostatectomy, TURP, radiation of the pelvis, or GreenLight Laser Therapy.
• History of invasive rectal malignancy or other pelvic malignancy, regardless ofdisease-free interval.
• The score for Question 16 (i.e., "Overall, how big a problem have your bowel habitsbeen for you during the last 4 weeks?") of EPIC questionnaire is 3 or above.
• Active inflammatory bowel disease (i.e., patients requiring medical interventions orwho are symptomatic) or documented history of inflammatory bowel disease requiringintervention.
• Prior pelvic radiotherapy for any reason.
• Documented lack of psychological ability or general health permitting completion ofthe study requirements and required follow-up.
• Documented decisionally impaired persons who have a diminished capacity to understandthe risks and benefits of participation in research and to autonomously provideinformed consent.
• Subjects who participated in a clinical trial of an investigational device, drug orbiologics within the past 30 days.
• Subjects who are currently undergoing any cancer drug treatment. However, patients whohad received cancer drug treatment and stopped the treatment for >4 weeks prior to thestart of radiotherapy can be included. (Hormone therapy is allowed if judgedappropriate and necessary by the treating physicians.)