ESTRO 2025 - Abstract Book

S1620

Clinical – äediatric tumours

ESTRO 2025

1108

Digital Poster Conventional or Hypofractionated Radiation for Diffuse Intrinsic Pontine Glioma: Institutional Outcomes from an Asian Country Ng Hoong Hoong 1 , Munira Mohd Rejab 1 , Foo Jen Chun 2 , David Lee 1 , Nisha Shariff 1 1 Department of Clinical Oncology, University Malaya Medical Centre, Kuala Lumpur, Malaysia. 2 Department of Paediatrics, University Malaya Medical Centre, Kuala Lumpur, Malaysia Purpose/Objective: Diffuse Intrinsic Pontine Glioma (DIPG) remains a fatal pediatric brain tumour with radiation therapy being the most effective treatment to date. However, global variations in radiation doses, dose fractionation and reirradiation practices exist. We report our institutional experience comparing conventional fractionation (CF) and hypofractionated (CF) radiation for DIPG. Material/Methods: We retrospectively reviewed all patients 18 years and below who were treated for DIPG in University Malaya Medical Centre, Malaysia from March 2014 to December 2023. Data was retrieved from electronic medical records and MOSAIQ (v2.64) oncology information system. Primary outcomes were overall survival (OS) after completion of radiation while secondary outcomes were progression free survival (PFS) after radiation and steroid use. Results: A total of 8 patients were treated in our centre with a median age of 9 years. Radiation therapy was initiated at a median of 30 days following the initial diagnostic MRI. Five patients underwent stereotactic biopsy. Four patients were treated with CF (54-59.4Gy in 1.8Gy per fraction), while the remaining 4 received HF (39Gy in 3Gy per fraction); half of the cohort (50%) were treated with intensity modulated radiation therapy (IMRT). The median overall survival for the whole cohort was 10 months, with significantly longer survival in the CF group compared to the HF group (19 months vs. 7 months, p=0.023). The median PFS was 3 months for CF and 4 months for HF radiation, which was not significantly different (p=0.389). There was no difference in the median time from diagnosis to the start of radiation between both groups. Neurological improvement was observed in 75% of patients across both fractionation groups. One patient in the CF group received reirradiation with 36Gy in 20 fractions, 5 months after the initial radiation course. Steroids were required during radiation in 7 patients and 6 patients were steroid-free by the end of radiation. However 2 patients in the HF group restarted steroid use within 14 days post treatment. All patients completed treatment, with 25% experiencing treatment delays and 50% requiring hospitalisation for symptom management during radiation.