Adaptive planning for 5 fraction arm
Adaptive planning will be permitted for the 5 fraction arm.Prior to treatment, each patient will undergo an MRI scan.2D shifts will be performed to align relevant anatomy (bladder wall, rectum, prostatic fossa).Simulation contours will be rigidly copied to the patient's MRI scan. If delineation changes, the scan will be recontoured.Predicted dose algorithm will determine if treatment dose parameters meet planning dose parameters.Patients will undergo adaptive planning if the treatment dose parameters do not meet the planning parameters and per the protocol planning parameters as outlined (see Additional File 