Implementation of tumour treating fields for glioblastoma in Belgium: real-world outcomes from a Belgian tertiary centre

Objectives Tumour treating fields (TTF) improve survival in newly diagnosed glioblastoma (GBM) in randomized trials, but real-world impact in Belgium remains unclear due to limited access and lack of reimbursement. This study evaluates progression-free survival (PFS) and overall survival (OS) in Belgian patients with newly diagnosed GBM treated with TTF alongside standard therapy.Methods We conducted a retrospective single-centre cohort study at UZ Leuven including patients with histologically confirmed newly diagnosed GBM treated with TTF between April 2019 and July 2026. TTF was initiated during adjuvant temozolomide. Clinical, molecular and treatment data were extracted from institutional records. Primary outcomes were PFS and OS from diagnosis. Kaplan–Meier survival analyses were performed, including subgroup analyses by MGMT status, device adherence (>75%), and extent of resection.Results Twenty-eight patients were analysed (median age 52 years; 71% male). MGMT promoter methylation was present in 29% and gross total resection was achieved in 50%. Adherence exceeded 75% in 96%. Median PFS was 6.8 months and median OS 24.6 months, comparing favourably with EF-14 outcomes. ECOG status predicted survival (p = 0.04). Survival was not associated with MGMT status or adherence. Gross total resection showed a clinically meaningful association with improved OS (30.7 vs 8.2 months; p = 0.07). Treatment was well tolerated.Conclusion In this real-world Belgian cohort, TTF with standard therapy yielded survival outcomes consistent with or exceeding pivotal trials. While clinical benefit appears evident, implementation remains challenged by financial costs. Further prospective Belgian studies are needed to assess cost-effectiveness and quality-of-life impact.