Advances in Radiation Oncology · Published 2026-07-01 · DOI 10.1016/j.adro.2026.102145
Kazuya Takeda, Shinsaku Okuda, Rei Umezawa, Takaya Yamamoto, Noriyoshi Takahashi, Ken Takeda, Keiichi Jingu
Purpose: We evaluated the real-world utility of hydrogel spacer placement for reducing radiation proctitis following prostate cancer radiation therapy using a large-scale claims database. Methods and Materials: We analyzed male patients from a Japanese administrative claims database (DeSC Database) who initiated primary radiation therapy between July 2018 and December 2024. Propensity score weighting using the average treatment effect on the treated method was applied to balance baseline characteristics between spacer users and nonusers. The primary endpoint was the occurrence of endoscopic gastrointestinal hemostasis, and the secondary endpoint was the diagnosis of radiation proctitis. Fine-Gray models were used to estimate subdistribution hazard ratios (sHRs) with death as a competing risk. Results: Of 7860 eligible patients, 1754 (22.3%) underwent spacer placement. For the primary endpoint (endoscopic hemostasis), the spacer group showed a statistically significant lower risk (sHR 0.26; 95% CI, 0.10-0.69; P = .007). The cumulative incidence at 36 months was 0.8% in the spacer group versus 2.3% in the nonspacer group. For the secondary endpoint (diagnosed proctitis), the sHR was 0.29 (95% CI, 0.16-0.53; P < .001), with a 36-month cumulative incidence of 1.4% versus 4.8%, respectively. Conclusions: This large-scale real-world analysis demonstrates that hydrogel spacer placement is associated with a significantly lower incidence of severe radiation proctitis requiring endoscopic hemostasis.
Abstract from DOAJ. Public domain (CC0 1.0).
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Takeda, K., Okuda, S., Umezawa, R., et al. (2026). Impact of Hydrogel Spacer on Radiation Proctitis After Prostate Cancer Radiotherapy: A Large-Scale Claims Database Analysis. Advances in Radiation Oncology. https://doi.org/10.1016/j.adro.2026.102145