- Patients with biopsy proven (completed and/or reviewed at MSK) adenocarcinoma of the prostate, who will undergo external beam radiotherapy using conventional fractionation IGRT including moderate hypofractionated radiation, low rate brachytherapy alone, low dose brachytherapy combined with supplemental image guided radiation (including IGRT, EBRT, and SBRT), SBRT, or proton radiotherapy.