Clinical and Patient-Reported Benefits of Rectal Spacers in Prostate Cancer

In this segment, the panel examines the clinical and patient-reported outcomes that define successful rectal spacer use in prostate radiotherapy. They explain that the primary metrics relate to gastrointestinal toxicity, including grade 1 symptoms such as mild diarrhea or increased bowel frequency, and more consequential grade 2 events requiring medical or surgical intervention. Rectal spacers consistently reduce both acute and long-term GI side effects by shielding the rectum from high-dose radiation, thereby lowering the risk of radiation proctitis and improving quality of life after treatment. The discussion highlights differences among spacer technologies: while earlier studies of SpaceOAR did not demonstrate significant reductions in grade 2 toxicity—likely due to conventional fractionation—newer evidence shows that Barrigel achieves meaningful decreases in both grade 1 and grade 2 events, even in hypofractionated and SBRT settings. They note that balloon-based systems and BioProtect have not yet shown similar grade 2 benefits, underscoring the importance of device selection in optimizing patient outcomes.