ESTRO 2025 - Abstract Book

S657

Clinical - CNS

ESTRO 2025

Results: The mean overall 5-year local control rate was 90%, and the median follow-up period was 62 months, ranging from 24 to 87 months. Among the 43 patients analyzed, 9% (4 patients) demonstrated consistent growth, while 28% (12 patients) exhibited transient expansion. CNE was observed in all cases with either consistent growth or transient expansion. Newly enhanced regions was observed following the appearance of CNE in all cases with consistent growth, whereas no new enhancement was observed in cases of transient expansion. Conclusion: New enhancement following CNE is a potential predictor of persistent growth of vestibular schwannomas after radiotherapy.

Keywords: Stereotactic radiotherapy, Radiological predictors

References: 1. Yamazaki M, Takamatsu S, Iwata Y, Sakurai T, Taka M, Kobayashi S, Gabata T, Mizuno E. Notch appearance as a novel radiological predictor of transient expansion and good outcome of expanding schwannoma after radiotherapy. Discov Oncol. 2024 Mar 19;15(1):79. doi: 10.1007/s12672-024-00936-y. PMID: 38503989; PMCID: PMC10951174.

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Digital Poster Clinical outcome and Deep learning imaging characteristics of patients treated by radio-chemotherapy for a “molecular” glioblastoma Caroline Zerbib 1 , Lucas Robinet 1,2,3 , Soleakhena Ken 4 , Ana Cavillon 5 , Margaux Roques 6 , Delphine Larrieu 7 , Aurore Siegfried 8,9 , Franck Emmanuel Roux 10,9,11 , Amhad Berjaoui 3 , Elizabeth Cohen-Jonathan Moyal 1,2,11 1 Radiation Oncology, Institut Universitaire du Cancer de Toulouse Oncopole, Toulouse, France. 2 INSERM UMR 1037, Cancer Research Center of Toulouse (CRCT), Toulouse, France. 3 IRT Saint-Exupéry, IRT Saint-Exupéry, Toulouse, France. 4 Department of Engineering and Medical Physics, Institut Universitaire du Cancer de Toulouse Oncopole, Toulouse, France. 5 Biostatistics & Health Data Science Unit, Institut Universitaire du Cancer de Toulouse Oncopole, Toulouse, France. 6 Department of Neuroradiology, Hopital Pierre Paul Riquet, CHU Purpan, Toulouse, France. 7 Department of Medical Oncology & Clinical Research Unit, Institut Universitaire du Cancer de Toulouse Oncopole, Toulouse, France. 8 Pathology and Cytology Department, Institut Universitaire du Cancer de Toulouse Oncopole, Toulouse, France. 9 CerCo, CNRS, UPS, CHU Purpan, Toulouse, France. 10 Department of Neurosurgery, Hopital Pierre Paul Riquet, CHU Purpan, Toulouse, France. 11 University Toulouse III Paul Sabatier, University Toulouse III Paul Sabatier, Toulouse, France Purpose/Objective: The presence of a TERT promoter mutation, EGFR amplification, or gain of chromosome 7 combined with loss of chromosome 10 in IDH wild type (wt) astrocytoma, is currently sufficient to classify them as a glioblastoma. However, to date, survival data for these glioblastoma subtypes (molecular glioblastoma (mGB)) are poorly studied and remain controversial. The aim of our study was to describe the therapeutic response of these mGB and better characterize them with radiomics models. Material/Methods: We retrospectively enrolled 132 patients with glioblastoma, treated by radio-chemotherapy. We compared survival data of glioblastoma defined by histologic criteria (hGB) with mGB. We estimated the predictive power of ML and DL models to differentiate mGB without CE from LGG on MRI, using different classifiers and features extracted from FLAIR hypersignal segmentation.