Impact of Carmustine wafer implantation in epileptic seizures of newly diagnosed glioblastomas, IDH-wildtype in adults

Purpose. The impact of Carmustine wafer implantation on epileptic seizure control in adult patients with newly diagnosed supratentorial glioblastoma, IDH- wildtype, remains unclear. We assessed whether Carmustine wafer implantation influences postoperative seizure control. Methods. We conducted an observational, retrospective, single-centre cohort study at a tertiary neurosurgical oncology center between January 2006 and December 2024. We included adults treated with surgical resection for a newly diagnosed supratentorial glioblastoma, IDH -wildtype with or without Carmustine wafer implantation in the early postoperative period and during the first six months of adjuvant oncological treatment. Results. 676 patients who benefited from a first-line surgical resection with (n = 257) or without (n = 419) Carmustine wafer implantation were included. Epilepsy at diagnosis was present in 244 patients (36.1%), with no difference in prevalence (35.8% vs. 36.3%, p = 0.483) or in preoperative seizure control (96.1% vs. 92.1%, p = 0.070) between groups. Uncontrolled seizures occurred in 17.6% (n = 43/244) of patients in the early postoperative period and in 18.6% (n = 41/221) of patients during the first six months of adjuvant oncological treatment. In multivariable analysis, preoperative uncontrolled seizures (adjusted Odds Ratio 76.9, 95%CI 34.5-187.7, p < 0.001) was independently associated with uncontrolled seizure in the early postoperative period, while Carmustine wafer implantation was not (aOR 0.78, 95%CI 0.36–1.60, p = 0.496). Similarly, a history of epilepsy at diagnosis (aOR 2.38, 95%CI 1.43–3.98, p < 0.001), but not Carmustine wafer implantation (aOR 0.92, 95%CI 0.55–1.54, p = 0.761), predicted uncontrolled seizures during the first six months of adjuvant oncological treatment. Conclusion. Carmustine wafer implantation does not impact the risk of uncontrolled epileptic seizures in the postoperative and adjuvant oncological treatment periods. No specific adaptation of antiseizure medication is required following Carmustine wafer implantation for newly diagnosed supratentorial glioblastoma, IDH- wildtype patients.