A Pilot Study of Ultra-High-Dose Hypofractionated or Single-Dose Radiotherapy for Intermediate Risk Prostate Cancer

This is open label feasibility study where patients enrolled in the study will undergo image-guided, intensity-modulated radiotherapy using the same equipment, techniques, and treatment-planning procedures as currently practiced at CCU. Eligible patients will receive either 45 Gy in 5 sessions each of 9 Gy delivered in one week (arm A) or 24 Gy in 1 session (arm B) to assess the dose limiting toxicities in the two groups. Patients will be randomized to arm A or arm B. Dose limiting toxicity (DLT) is defined as any Grade 3 urinary or rectal toxicity, based on NCI CTCAE v4.0, observed within 3 months of completion of protocol radiation. If, at any point in the conduct of the trial, DLTs are observed in three patients in a study arm, accrual to that arm will be terminated. There are three aspects of this study that will be different from the currently used standard treatment for definitive external beam treatment of prostate cancer: 1. The dose-fractionation scheme, as per the treatment arm. 2. Acquisition of a set of prostate biopsies at 24 months post treatment 3. Examination of imaging response based on multi-parametric MRI