ESTRO 2025 - Abstract Book

S660

Clinical - CNS

ESTRO 2025

group. Baseline characteristics were balanced between the two groups after propensity score matching (Table 1). With a median follow-up of 20 months, the BNCT group had a significantly longer median post-recurrence survival (18 months [95% CI: 11-26] vs. 10 months [95% CI: 6-14]) than the control group (HR: 0.53, 95% CI: 0.32-0.87; P = 0.012) in the matched analysis. In BNCT group, survival rates at 12 and 24 months after the first recurrence were 61.7% (95% CI: 47.6-80.0%) and 43.5% (95% CI: 29.1-65.2%), respectively, compared to 34.7% (95% CI: 22.6-53.2%) and 20.5% (95% CI: 10.9-38.7%) in the control group. This survival benefit persisted in the 3-month landmark analysis (Figure 1) and remained significant when BNCT initiation was treated as a time-dependent covariate (HR: 0.58, 95% CI: 0.35-0.97; P = 0.038). Multivariable Cox regression revealed that BNCT (P = 0.019) and extent of re resection (P < 0.001) remained as independent prognostic factors for post-recurrence survival. In contrast, the administration of BNCT did not result in better survival in patients with recurrent grade 4 IDH mutated gliomas (HR: 2.74, 95% CI: 0.36-0.57; P = 0.206).