The Impact of Postoperative Ischemic Changes on Survival Outcomes in IDH-wildtype Glioblastoma

Background The prognostic relevance of postoperative ischemia in glioblastoma (GBM) remains unclear. This study investigated the association between infarct volume and survival in patients with IDH-wildtype GBM. Methods We retrospectively reviewed 451 patients with IDH-wildtype GBM who underwent resection between 2013 and 2024 and had diffusion-weighted imaging within 72 hours postoperatively. Ischemic changes were defined as new areas of diffusion restriction and stratified into none/rim-only, small (<5 cm³), and large (≥5 cm³) infarcts. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan–Meier and Cox regression models adjusted for age, preoperative KPS, tumor size, extent of resection, MGMT status, adjuvant therapy, and postoperative deficits. Results Large infarcts were associated with shorter median PFS (7.0 months [95% CI: 5–9]) and OS (14.0 months [95% CI: 9–18]) compared to small infarcts and none/rim-only (PFS: p = 0.07; OS: p = 0.001). In multivariable models, infarct volume was independently associated with reduced OS (per cubic centimeter increase, HR = 1.02, 95% CI: 1.01–1.032; p = 0.003), while its association with PFS did not reach statistical significance (HR = 1.01, 95% CI: 1.0–1.02; p = 0.13). When modeled categorically, large infarcts remained predictive of shorter PFS (HR = 1.4, 95% CI: 1.01–1.9; p = 0.04) and OS (HR = 1.7, 95% CI: 1.2–2.4; p = 0.001). Conclusions Infarct volume is independently associated with survival in IDH-wildtype GBM. These findings highlight the clinical relevance of postoperative ischemia and may point toward ischemia-related mechanisms as targets for future therapeutic investigation.