Reirradiation for Patients With Recurrent Ependymoma Across the Age Spectrum

PurposeIn patients with locally recurrent ependymoma, previous data have shown that repeat radiation (RT2) with craniospinal irradiation (CSI) improves disease control compared with focal RT2 alone.This study aims to report long-term outcomes of adults and children with recurrent intracranial ependymoma, including those treated with CSI. MethodsIn this retrospective, single-institution study, we identified 48 patients treated with RT2 for recurrent ependymoma between 1999 and 2024.The primary endpoint was overall survival (OS) with start of RT2 as index time.CSI was prescribed to 23.4 or 36 Gy, followed by focal boost RT to 54 Gy.OS was estimated using the Kaplan-Meier method; groups were compared using the log-rank test. ResultsThe median age at initial diagnosis was 6.5 years (range 0.8-62.3),and majority pediatric (83% age < 18 years) with a posterior fossa (PF) tumor location (67%).Of 35 patients with molecular pathology available, 23 had PF-A and 11 had a ZFTA fusion.Median follow-up was 9.1 years.Gross total resection (GTR) of all disease prior to RT2 was associated with better 5-year OS (57% vs. 19%, p = 0.015).Among the 33 patients (69%) who had only local recurrence, the 5year OS was significantly higher with CSI RT2 (n=10) vs. focal RT2 (n=23) (78% vs. 36%, respectively; p = 0.040).In the subgroup of 24 PF local recurrences, 5-year OS was 83% for CSI (n=7) and 30% for focal RT2 (n=17) (p= 0.061).The 5-year OS for the 15 patients with disseminated-only or synchronous local and disseminated failures was 20%; all but one were treated with CSI RT2. ConclusionsIn this single-institution cohort of patients with recurrent ependymoma and long-term followup, GTR of the recurrence was associated with better survival, and locally recurrent patients treated with CSI RT2 had longer overall survival.Further work is required to determine the independent effects of CSI RT2 together with extent of re-resection.