Hypofractionated radiotherapy for multifocal or multicentric glioblastoma: a single-centre retrospective study

Background : Multifocal or multicentric glioblastoma (M/M GBM) is associated with poor prognosis and lacks a standardised radiotherapy approach. This study evaluated clinical outcomes, symptom trajectories, and survival after hypofractionated radiotherapy, with or without concurrent and adjuvant temozolomide, in patients with M/M GBM. Materials and methods: We conducted a retrospective chart review of patients with newly diagnosed M/M GBM who completed planned hypofractionated radiotherapy at King Faisal Specialist Hospital and Research Centre, Jeddah, between January 2015 and August 2024. Data on demographics, disease, treatment, toxicity, symptoms, radiographic response, progression-free survival (PFS), and overall survival (OS) were analysed. Survival outcomes were estimated using the Kaplan–Meier method and compared using the log-rank test. Results: Eighteen patients were included. Most patients received whole-brain radiotherapy (WBRT; 88.9%), most commonly at a dose of 37.5 Gy in 15 fractions. Mean OS was 10.83 months [95% confidence interval (CI): 4.93–16.72], and mean PFS was 4.41 months (95% CI: 2.43–6.39). The number of lesions and radiation dose were significantly associated with OS and PFS; post-radiotherapy Eastern Cooperative Oncology Group (ECOG) performance status was also associated with PFS. Neurological symptoms were stable or improved in 12 patients (66.7%), although ECOG performance status did not significantly improve after radiotherapy. Conclusions: Hypofractionated radiotherapy, most often delivered as WBRT in this cohort, was associated with symptom stability or improvement in a subset of patients with M/M GBM and an acceptable documented toxicity profile. Higher radiation dose and fewer lesions were associated with longer survival. Given the retrospective design and small sample size, these findings should be interpreted as hypothesis-generating and warrant validation in larger multi-institutional studies.