ESTRO 2025 - Abstract Book

S760

Clinical - CNS

ESTRO 2025

4346

Digital Poster Repeat Chemoradiation vs. Re-Irradiation Alone in Recurrent Gliomas Miguel J.H. Schroën 1 , Anouk M. de Jong 2 , David J.A. Palm 1 , Joost J.C. Verhoeff 3 , Catharina M.L. Zegers 1 , Ruud Houben 1 , Linda Ackermans 4 , Monique M. Anten 5 , Ann Hoeben 6 , Danielle B.P. Eekers 1 , Inge Compter 1 1 Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, Netherlands. 2 Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, Netherlands. 3 Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands. 4 Department of Neurosurgery, Maastricht University Medical Centre+, Maastricht, Netherlands. 5 Department of Neurology, GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, Netherlands. 6 Division of Medical Oncology, Department of Internal Medicine, GROW-school of Oncology and Developmental Biology, Maastricht University Medical Center +, Maastricht, Netherlands Purpose/Objective: Glioblastoma (GBM) typically recurs within the first two years after initial treatment. No standard life prolonging treatment options have been established for recurrent GBM. This study aims to compare the efficacy of rechallenge concurrent chemoradiation with temozolomide (TMZ) against single treatment radiation treatment (RT) and to identify factors influencing survival in these patients. Material/Methods: This single-center study contains a retrospective analysis of 136 patients with recurrent gliomas who received re irradiation between January 2009 and December 2023. The median age was 48.8 years (range 22–81). The initial diagnosis was based on the pathology report. Re-irradiation was administered as monotherapy or as RT (54 Gy in 1.8 Gy fractions) concurrent with TMZ. Overall survival was compared using Kaplan-Meier survival and log-rank tests. Furthermore, significant confounding variables determined by univariate analysis were subjected to multivariable Cox proportional hazards analysis with propensity scoring.

Results:

At recurrence, the study predominantly included GBM (71.3%), followed by oligodendroglioma (II: 5.1%, III: 7.4%), astrocytoma (II: 3.7%, III: 11.8%), and other tumors (0.7%). Patients were treated with either repeat concurrent chemoradiation (31.6%), including those who received (stupp+restupp) 54 Gy in 1.8 Gy fractions plus temozolomide (n = 16, 11.8%), or other re-irradiation alone regimens (68.4%). The mean overall survival (OS) was 10.4 months (47.3 months from the initial diagnosis), and the mean progression-free survival was 4.2 months. Repeat concurrent