Investigating Variations in Rectal Size on CT Planning Data Set and CBCT for Patients Undergoing Radiation Therapy to their Prostate/prostate Bed during the First Thirteen Days of Treatment

Based on patient feedback and current literature, the Radiation Oncology Genito-Urinary Disease Site Team at Peel Regional Cancer Center decided to implement a change in the bladder/bowel preparation protocol for all prostate/prostate bed patients undergoing radical radiation therapy treatment. Part of this protocol change involved a large research study to compare the current (old) bladder/bowel preparation (using enemas prior to CT, taking milk of magnesia daily, stressing full bladder) with the new bladder/bowel preparation (no rectal preparation, stressing both hydration and full bladder). One of the endpoints chosen to observe was how the rectum changes over time, and if it changes between the old and new protocols. This abstract presents the findings of rectal variation in phase 1 patients.