Improving Sexual Quality of Life - Randomized Trial of Two vs Five MRI Guided SABR Treatments for Prostate Cancer

Prostate Stereotactic ablative body radiotherapy (SABR) is an established technique that delivers radiation in a non-invasive approach for men with prostate cancer. The treatment regimen is given in total of 5 fractions with one treatment per day at every other day or weekly sessions. Ultra-hypofractionated radiotherapy (UHRT) is an emerging monotherapy for localized prostate cancer however, several trials have observed demonstrating superior biochemical control of a two-fraction (HDR) over single-fraction approach. The study aims to compare an experimental shorter course of prostate ultra-hypofractionated radiotherapy (UHRT) that will deliver what is expected to be an equivalent amount of radiation as given in the standard 5 treatment regimen. UHRT is given in 2 treatments with one treatment a week for 2 consecutive weeks.

Inclusion Criteria:Histologically confirmed prostate adenocarcinoma (centrally reviewed)Low or favorable intermediate risk disease. Patient must meet one of the following categories:Low risk - T1-T2b, grade group 1, AND PSA < 10 ng/ml;Favorable riskOnly one of the following intermediate risk factors - cT2c, grade group 2, or PSA 10-20 ng/ml; orGrade group 3 AND PSA < 20, AND <cT2c AND absolute percentage pattern 4/5 is <10%Exclusion Criteria:Androgen deprivation therapy (LHRH-agonists or antiandrogens) given or plannedPrior pelvic radiotherapyAnticoagulation medication (if unsafe to discontinue for gold seed insertion)Diagnosis of bleeding diathesisLarge prostate (>90cm3) on imagingImmunosuppressive medicationsInflammatory bowel diseasePresence of dual hip prosthesesContraindications to having MRI