SpaceOAR and Barrigel are rectal spacers commonly used during prostate radiation. However, they have different methods of application. This study retrospectively compared dosimetry for over 800 patients who received prostate radiation with SpaceOAR (42%), Barrigel (38%), or no spacer (20%). SpaceOAR insertions has significantly larger volume (13.8 v 5.1cc), which led to greater rectal separation and better overall rectal dosimetry when compared to Barrigel. However, among plans where there were similar volumes of SpaceOAR and Barriegel, the latter had better rectal dosimetry. The findings suggest that the volume of the insertion rather than symmetry had a greater impact on rectal dosimetry. Finally, rectal wall infiltration occurred in 2.4% of SpaceOAR cases and 0% of Barrigel cases. | Prusty, Adv Radiat Oncol 2025
