ESTRO 2025 - Abstract Book

S729

Clinical - CNS

ESTRO 2025

Results: At present, a total of 13 patients were enrolled in the trial. Median age was 9 years old (range 3-21) and male: female was 5:8. Median follow-up was 168 days (range, 19-314). Among the patients who have experienced disease progression, 6-month PFS was 100% and adverse events were mainly at grade 1 or grade 2. No adverse events above grade 3 occurred. Currently, there have been no treatment termination events due to adverse events. The common adverse reactions were hypothyroidism and gastrointestinal discomfort, and there were no deaths during the treatment period.

Conclusion: The combination of radiotherapy and anlotinib is safe thus far and observed efficacy outcomes are intriguing.

Keywords: Malignant Brainstem Glioma, Anlotinib, Children

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Digital Poster Is MR imaging necessary for producing clinically appropriate hippocampal contours for HA-WBRT? Owen Rodrigues, Melody Qu, Timothy Nguyen, Glenn Bauman, Andrea Vucetic, Shaheer Shahhat, Sympascho Young, Terence Tang, George Rodrigues, John Patrick Radiation Oncology, Verspeeten Family Cancer Centre, London, Canada Purpose/Objective: To prepare a HA-WBRT plan to potentially reduce neurotoxicity, a radiation oncologist must contour the two hippocampi which can be time-intensive and traditionally requires access to a fused MR scan for CT simulation [1 4]. This study seeks to assess the clinical appropriateness of CT-based hippocampal contours created by an AI automatic contouring system to MR-based consensus and clinician contours. If MR imaging is not essential to hippocampal contouring, the clinical care path for planning HA-WBRT would be simplified with cost savings that may be important in resource-limited jurisdictions. Material/Methods: Sixteen anonymized HA-WBRT patients were included in this study. Four types of contours were generated or available for study and included: 1. Consensus based “gold standard” contours generated by use of the STAPLE algorithm with seven ROs contouring using MR-fused CT simulation information without access to auto-contours. 2. MRI based Limbus AI auto-contours (limbus.ai). 3. CT simulation based (without MR imaging) Limbus AI auto-contours. 4. Clinical contours generated by the treating RO prior to this study (with access to MR-fused CT simulation imaging and Limbus AI auto-contours). For each patient, four contours were generated of both left and right hippocampi and their respective PRV (5mm isotropic expansion) avoidance contours. Various comparisons between contour generation approaches were conducted using Dice Coefficient analysis and descriptive statistical assessment of the magnitude of over- and under-contouring.