Radiation-Induced Brain Necrosis among patients with Nasopharyngeal Cancer Treated with Proton vs Photon Radiotherapy
Menée à l'aide de données 2013-2025 portant sur 256 patients atteints d'un cancer du rhinopharynx, cette étude analyse le risque de nécrose cérébrale radio-induite en fonction du type de radiothérapie utilisée (photons ou protons)
Background: Radiation-induced brain necrosis (RIBN) is a late complication of radiotherapy (RT). Whether proton therapy reduces this risk relative to photon remains unclear in nasopharyngeal cancer (NPC).
Methods: We retrospectively reviewed consecutive adults with NPC who received definitive chemoradiotherapy with photon intensity-modulated radiotherapy (IMRT) or proton RT between June 2013 and March 2025 and ≥6 months of follow-up. Cumulative incidence of brain necrosis (BN) was estimated treating death without BN as a competing event (Gray test); cause-specific Cox regression identified associated factors; overall survival (OS) was compared by log-rank test.
Results: Of 256 patients, 79 (30.9%) received proton and 177 (69.1%) IMRT; median follow-up was 43 and 87 months, respectively. BN developed in 5/79 (6.3%) proton and 9/177 (5.1%) photon (P =.7674). The 2- and 5-year cumulative incidence of any-grade RIBN was 6.2% and 9.7% for proton versus 1.8% and 5.2% for photon (Gray P =.2342); for grade ≥2 RIBN, 4.7% and 4.7% versus 1.2% and 2.5% (Gray P =.3132). In exploratory univariable cause-specific Cox analyses, T4 disease was associated with a higher hazard of RIBN (HR, 8.48; 95% CI, 1.83-39.30; P =.0063). The association between proton therapy and RIBN was not statistically significant (HR, 1.85; 95% CI, 0.6-5.68; P =.2832). OS did not differ (5-year, 90.0% proton vs 80.7% photon; log-rank P =.1573).
Conclusions: Proton therapy was not associated with a lower risk of RIBN than photon in NPC. Exploratory univariable analysis showed an association between T4 disease and RIBN. No statistically significant differences in survival or toxicity outcomes were observed between modalities.
European Journal of Cancer , résumé, 2026