Methods/Design
toxicity, TTP, prostate
TTP, PROSTATE
This is a phase II non-blinded multi-institution randomized non-inferiority trial comparing patient reported outcomes in GI or GU toxicity at baseline and 24 months post treatment in men with low or intermediate risk PCa receiving either 2 or 5 fraction MR-LINAC guided SBRT. Acute and late patient reported changes in GI, GU and sexual symptoms as well as time to progression (TTP) and overall survival (OS) will be evaluated at 3, 6, 12, 24 and 60 months post-treatment. We plan to enroll 136 patients with an expected rate of accrual of approximately 120 patients per year. MR-LINAC SBRT will be delivered with 37.5 Gy in 5 fractions or 25 Gy in 2 fractions to the prostate ± seminal vesicles, with an optional simultaneous integrated boost (SIB) of up to 45 Gy for the 5 fraction arm and up to 28 Gy for the 2 fraction arm. Patients will be randomized to treatment arms in a 1:1 ratio using a computer-generated randomization scheme. Patients on the 5 fractions arm will receive their radiation on non-consecutive days. Patients on the 2 fraction arm will be treated with at least 6 days between treatments. For both arms, treatment should ideally be completed by 2 weeks post-start date.