SURG-89. GammaTile Brachytherapy for Reirradiation in Recurrent Glioblastoma: A Retrospective Single-Institution Case Series

BACKGROUND Re-radiation plays a complex role in the management of recurrent glioblastomas. Because of limited therapeutic options, re-radiation is often considered to optimize survival outcomes while preserving quality of life. However, repeat radiation is associated with the risk of radiation necrosis and neurological decline. Here, we reviewed the clinical outcome of recurrent glioblastoma patients who underwent re-radiation through brachytherapy. METHODS A retrospective study included 30 patients with recurrent glioblastoma who underwent previous external beam radiation (EBRT, median dose of 60 Gy, range 40–66 Gy). Seven patients (23.3%) received a second EBRT course (median dose of 30.0 Gy, range 22-36 Gy) before brachytherapy. All underwent surgical resection at the time of recurrence, and brachytherapy was administered through GammaTile (GT) implant. Clinical and imaging characteristics were collected. RESULTS The mean age of the study cohort was 57.6 +/- 10.8 years, with 22 men and 8 women. Median time from the end of first EBRT to GT brachytherapy was 331 +/- 251 days. Procedural morbidity was noted in 1 patient, attributable to the surgery rather than the brachytherapy. All patients were maintained on corticosteroids through the brachytherapy course. The 30-day and 90-day readmission risk were 16.7% and 20.0%, suggesting most patients tolerated the re-radiation well. Twenty patients (66.7%) ultimately required bevacizumab, though it is unclear whether the need was driven by radiation necrosis or tumor progression. Mean overall survival was 354 days (range: 10-923) from the time of brachytherapy. CONCLUSION Resection with brachytherapy is a safe and effective option for reirradiation in recurrent glioblastomas. Neurological symptoms were manageable with corticosteroids or bevacizumab.