Safety and efficacy of salvage reirradiation for recurrent high-grade gliomas: a retrospective analysis

PURPOSE: To assess the feasibility, safety, and clinical outcomes of salvage reirradiation, using intensity-modulated radiotherapy (IMRT) with a total dose of 30 Gy and cumulative equivalent dose in 2 Gy fractions (EQD2) limited to ≤ 96 Gy in patients with recurrent high-grade gliomas. MATERIALS AND METHODS: This retrospective study included 24 patients with recurrent high-grade gliomas who underwent IMRT-based reirradiation between 2014 and 2021. Treatment planning was performed using computed tomography-magnetic resonance imaging fusion images, and radiotherapy was delivered via IMRT or volumetric-modulated arc therapy. No concurrent chemotherapy was administered, and the cumulative EQD2 to the brain was restricted to 96 Gy. RESULTS: The median follow-up was 8 months (range, 1-31 months). The median overall survival was 8 months, with 1- and 2-year overall survival rates of 29% and 4%, respectively. No grade ≥ 2 toxicity or cases of radiation necrosis were observed. All patients completed the planned treatment course without interruption. CONCLUSION: Salvage reirradiation using IMRT with an EQD2 limited to ≤ 96 Gy was a feasible and well-tolerated treatment strategy for select patients with recurrent high-grade gliomas. This approach may offer a modest survival benefit with minimal toxicity and warrants further investigation in prospective trials.