MRI-guided Locoregional SBRT Prostate Program

The implementation of Magnetic Resonance Image Guided Radiotherapy (MRgRT) into a Prostate Cancer Program will allow to reproduce the results obtained with state-of-the-art brachytherapy combined with EBRT with the added advantage of convenience. Rationale In the radiation setting, MRI provides superior soft tissue contrast compared to standard onboard X-ray imaging improving inter- and intra- observer delineation variation. MRgRT offers the opportunity to adapt the plan at each fraction to the anatomical changes seen. This is especially important in prostate cancer where the prostate is subject to large intra and/or interfractional position changes due to rectal and bladder filling changes. Primary Objectives A. To achieve a 5-year biochemical relapse-free survival of 85%. B. To decrease urinary grade 3 or greater toxicity below 5% and rectal grade 3 or greater toxicity below 2%. Secondary Objectives A. Determination of blood and urine biomarkers of treatment response and toxicity . B. Determination of radiomics biomarkers of treatment response and toxicity . C. Determination of QOL with IPSS and EORTC QLQ-PR25