Association between rectal spacer use and bowel, urinary, and sexual dysfunction following prostate cancer...

Rectal spacing has been shown to reduce toxicity following external beam radiation therapy for prostate cancer. However, real-world evidence of effectiveness for rectal spacers with brachytherapy (BT) monotherapy remains limited. This study used U.S. claims datasets to assess the association between rectal spacer use and bowel, urinary, and sexual function following BT.

A retrospective study was conducted among patients treated with BT monotherapy for prostate cancer between 2015 and 2021, using Medicare 5% and 100% Files, MarketScan, and Premier Databases. Polyethylene glycol rectal spacer use was identified. Post-BT treatment diagnoses of bowel, urinary, and sexual dysfunction were evaluated using Cox proportional hazards models, adjusting for age, comorbidity, region, baseline dysfunction, secondary cancers, and BT modality (low-dose rate [LDR] or high-dose rate).

Among 13,858 BT monotherapy patients, 1198 (8.6%) received a spacer. Patients with spacer were younger and had fewer baseline dysfunctions. At 5-year median follow-up, spacer use was associated with significantly lower incidence of bowel (adjusted hazard ratio, aHR: 0.76, p = 0.027) and urinary (aHR: 0.84, p = 0.008) dysfunction. Sexual dysfunction trended lower (aHR: 0.79, p = 0.120), although not significant. In LDR patients, spacer use remained significantly associated with reduced bowel (aHR: 0.74, p = 0.021) and urinary (aHR: 0.83, p = 0.005) dysfunction. Significant associations were not found in high-dose rate patients.

In this large real-world study, rectal spacing as a standard-of-care intervention showed sustained significant benefit in reducing bowel and urinary dysfunction, which appeared to be greatest in those treated with LDR BT.