ESTRO 2025 - Abstract Book

S649

Clinical - CNS

ESTRO 2025

Material/Methods: Patient data was extracted from prospectively maintained databases. Clinico-pathological and demographic variables were summarized using descriptive statistics and analysed using measures of central tendency and dispersion. Outcomes of interest included Overall Survival (OS) and Progression Free Survival(PFS) and were analysed using the Kaplan Meier method. The log-rank test was used to test variables of prognostic significance. Results: The medical records of 121 patients (MPE-40, HE-28, OE-53) were extracted for analysis. A male gender predilection was observed in MPE and HGE respectively. Gross Total Resection (GTR)was performed in70%(MPE) 64%(HGE),39% (OE) respectively. For MPE, at a median follow up of 62 months(95%CI-51.9-72months), the 5-year PFS and OS were 68.5%(95%CI-53.1%-88.4%) and 89.5%(95%CI-78.8%-100%) respectively and GTR was associated with statistically significant improvement in OS {5 yr OS -100%(95%CI-100%-100%) vs.51.4%(95%CI-23.6%-100%), p value=0.013}. For HGE, at a median follow up of 30.3 months(95%CI-14.5-76.3 months),the 3-year Kaplan Meier estimates of PFS and OS were 35.8%(95%CI-18.7%-68.7%) and 52.7%(95%CI-32.9%-84.4%)respectively. For OE , at a median follow up of 11 months (95%CI-2-20 months),the 1- year PFS and OS were 85.7%(75.5%-97.3%) and 93.5% (95%CI-85.3%-100%) respectively. Radiotherapy delivered upfront for gross disease or symptomatic residual vis a vis as salvage at the time of recurrent or progressive disease was associated with a trend towards improved PFS{5-yrPFS-87.5%(95%CI-67.3%- 100%)vs.34.3%(95%CI-11.2%-100%),p value=0.067}in MPE patients. There were no instances of severe RTOG Grade 3 toxicities reported. Conclusion: Spinal ependymomas are uncommon tumors with variable histology and biology mandating multi-disciplinary management. Safe GTR should be attempted whenever possible. Post operative RT should be considered for residual tumor or high grade histology. Significant scope exists for improving outcomes in biologically aggressive spinal ependymomas subsets through collaborative multi-centric research with incorporation of molecular data. References: 1.Louis DN et al.WHO Classification of tumors of the Central Nervous System. Neuro Oncol 2021Aug 2;23(8):1231 1251 2.Kukreja et al.Outcome Predictors in the managment of Spinal Myxopapillary Ependymoma:an integrative survival analysis.World Neurosurgery 2015 May;83(5):852-9 3.Wu et al.Primary spinal anapaestic ependymoma: A single institutional retrospective cohort and systematic review.Front Oncol 2023 Feb 7;13:103085 Keywords: Spinal ependymoma,surgery, RT

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Digital Poster Hit-and-miss no more: Improving contouring precision in brain metastases using black blood MRI sequences Rafael D'Ambrosi 1 , Zhao Hui Chen Zhou 2 , Sandra Guardado 1 , Sandra Fernandez Alonso 1 , Virginia Rodriguez 1 , Ana Ramos 2 , Maria Angeles Perez-Escutia 1 1 Radiation Oncology, Hospital Universidario 12 de Octubre, Madrid, Spain. 2 Diagnostic Imaging, Hospital Universidario 12 de Octubre, Madrid, Spain Purpose/Objective: To evaluate the differences in GTV volume and concordance when contouring brain metastases using MRI black blood and 3D T1 post-contrast gradient-echo (GRE) sequences.