Hill, CiaranAlbohassan, Taha2025-12-272025https://hdl.handle.net/20.500.14154/77711Background: Perioperative cerebral ischaemia is frequently observed on early postoperative diffusionweighted imaging (DWI) following glioblastoma (GBM) resection. Experimental and clinical evidence suggests that surgically induced hypoxia may promote tumour aggressiveness, yet its clinical relevance remains unclear. Methods: We performed a retrospective cohort study of adults with newly diagnosed IDH-wildtype GBM who underwent surgical resection at a tertiary neurosurgical centre between January 2022 and January 2025. Early postoperative MRI with DWI (≤72 hours) was assessed for diffusionrestricted ischaemia. The primary outcome was time to radiological recurrence. Secondary outcomes included recurrence pattern, postoperative neurological deficits, and overall survival (OS). Survival analyses were conducted using Kaplan–Meier methods and Cox proportional hazards models stratified by extent of resection and adjusted for relevant covariates. Results: Sixty-seven patients with documented recurrence were included; 38 (56.7%) demonstrated postoperative ischaemia. Median time to recurrence was significantly shorter in patients with ischaemia compared with those without (8 vs 11 months; p = 0.038). Recurrence pattern did not differ between groups (p = 0.501). Median OS was 16 months in the ischaemia group and 20 months in the non-ischaemia group (p = 0.234). On adjusted analysis, postoperative ischaemia was associated with an increased hazard of death (HR 1.66, 95% CI 0.94–2.93; p = 0.079). Conclusion: Postoperative cerebral ischaemia following GBM resection is associated with earlier tumour recurrence and may confer an adverse survival signal. Prospective studies incorporating volumetric assessment of ischaemia are warranted.29enGlioblastomacerebral ischaemiadiffusion-weighted imagingtumour recurrenceneurosurgical outcomesThesis