SUPR-SABR for Prostate Cancer

This single arm trial will investigate a novel way to plan and deliver SABR for prostate cancer. Prostate-directed SABR will be high-dose SABR (40 Gy in 5 fractions) with central sparing of the urethra and peripheral sparing of the rectum and pudendal arteries (SUPR-SABR). This study tests the hypothesis that genitourinary (GU) and gastrointestinal (GI) toxicity rates following SUPR-SABR are comparable to (or possibly lower than) historical GU and GI toxicity rates following standard SABR (stSABR) with 36.25 Gy in the treatment of low- and intermediate-risk prostate cancer.

Inclusion Criteria:Provision of signed and dated informed consent formStated willingness to comply with all study procedures and availability for the duration of the studyMale patients aged 18 years and olderIn good general health as evidenced by medical history to be a candidate for curative-intent prostate cancer treatmentAbility to receive pelvic radiotherapy and be willing to adhere to the SUPR-SABR regimenPreviously untreated prostate cancer (with cytotoxic chemotherapy, surgical or radiation therapy)Localized adenocarcinoma of the prostate with the following features:cT1-T2cPSA<20Patients receiving a 5-alpha reductase inhibitor must have a PSA <10Grade Group 1-3Patient willing and able to complete the EPIC questionnaire at time of registration and 1-, 12-, and 24- months post treatmentProstate volume <120 ccHistory and physical including a digital rectal exam 90 days prior to registrationECOG performance status 0-2Be eligible and willing to undergo MRI prostate and pelvis as a component of RT planningBone and soft tissue imaging as clinically indicated (for unfavorable intermediate risk or symptomatic patients only) within 120 days prior to registrationIPSS score ≤20 at time of initial history and physical with treating radiation oncologistExclusion Criteria:Female patients (due to lack of prostate gland)Concurrent use of testosterone supplementationKnown homozygous for ATM pathogenic mutationPrior pelvic RTTreatment with another investigational drug for prostate cancerPre-existing conditions or overall health status which disqualifies the patient from curative-intent RTPrior or concurrent invasive pelvic malignancy (except non-melanomatous skin cancer) or lymphomatous or hematogenous malignancy, unless disease free for a minimum of 5 yearsPatients with distant metastases from prostate cancerPatients with lymph node involvement by prostate cancerPrior prostatectomy, cryotherapy, high-intensity focused ultrasound, pelvic irradiation overlapping with fields needed for prostate cancer treatment, prostate brachytherapy, or previous cytotoxic chemotherapy for prostate cancerUnwilling or unable to provide informed consent