A Study of MRI-guided High-dose Radiation Therapy in Prostate Cancer

"Patients enrolled in this study will undergo ultra-hypofractionated radiation utilizing MR guided, daily online adaptive planning. Patients will receive a standard dose of 8 Gy/fraction for five fractions for a total dose of 40 Gy to the prostate with a simultaneously-delivered boost of 9 Gy for five fractions (clinically non-standard dose of 45 Gy total) to a single dominant lesion with a maximum dimension of at least 0.5 cm, as determined on the pretreatment diagnostic T2 MRI imaging. In the setting of two similarly-sized dominant lesions, both will be boosted."