To plan for radiation therapy, patients will have standard computed tomography (CT) and MRI scans of the pelvis and prostate. In addition, CT and MRI scans will be done to determine if the prostate is in a good position for brachytherapy. For these scans, patients will have an enema and a tube will be placed in the rectum. They will then lie still on their side for about 45 minutes during the scan. Patients who have blood in their urine will also undergo cystoscopy. This is an examination of the bladder using a small camera that is advanced through the penis into the bladder.