The Use of High-Volume Endorectal Balloon is Effective to Reduce Doses of Rectum and Bladder in ProstateCancer Patients Treated with Linac-Based StereotacticBody Radiotherapy

Abstract

In this study, the effect of endorectal balloon (ERB) on risky organ doses was investigated in patients with low-medium risk prostate cancer treated with Stereotactic body radiotherapy (SBRT).METHODSIn the 17 patients, CT simulation and treatment was performed with an empty rectum and no ERB was used (non-ERB group). ERB filled with 100-150 cc air into 15 patients was placed in the rectum and identified with the ERB group. SBRT was performed to be delivered with volumetric modulated arc, with 10 FFF photon beams, using a linear accelerator with a high definition MLC. Dosimetric parameters for the rectum, bladder and penilbulb were compared between the two groups as a retrospective. Independent samples t-tests were performed to examine the differences between the two groups.RESULTSThe mean dose given to the rectum was lower in the ERB group than in the non-ERB group, and a statistically significant dose reduction of 149.4 cGy per fraction was found in the ERB group (p