ESTRO 2025 - Abstract Book

S1630

Clinical – äediatric tumours

ESTRO 2025

Median time from initial RT to progression was 5 months. Eleven patients underwent rRT, achieving a median OS of 18.3 months. Favourable radiological responses to initial RT correlated with better progression-free survival (PFS) (11.8 vs. 9.3 months). Although differences in PFS between rRT versus no rRT (18.1 vs 14.2) and RT alone versus RT plus additional treatments (13.1 vs 16.4) were not statistically significant, both approaches seemed to improve clinical outcomes. Our analyses also yield results similar to those of a Spanish multicenter study that included part of our analyzed population, focusing on reirradiation outcomes in patients with recurrent DIPG. Both studies underscore rRT’s safety and ability to improve symptoms while extending survival. Notably, the multicenter study identified a correlation between longer intervals from diagnosis to rRT and improved OS, along with higher rRT doses (>20 Gy). Conclusion: Our clinical results, including safety and efficacy, align with previous studies for both initial and recurrent cases. Biopsies and systemic therapies haven’t proved additional benefits. Hypofractionated RT (hFRT) emerges as a promising standard, as phase 3 trials have shown it alleviates symptoms and reduces treatment burden, improving quality of life. Despite these findings, the ideal candidates for rRT and optimal irradiation protocols remain undefined. Prospective, multicenter studies are crucial to tailoring treatment approaches and improving outcomes for this challenging disease. Radiosensitivity research at our center seeks to refine RT indications further. References: - Panizo E, Vazquez-Gomez F, et al. Re-irradiation for progressive Diffuse Intrinsic Pontine Glioma (DIPG): The Spanish experience. Neuro Oncol. 2024 Jun 18;26(Suppl 4):0. doi: 10.1093/neuonc/noae064.116. PMCID: PMC11183369. - Park J, et al. Hypofractionated radiotherapy versus conventional radiotherapy for diffuse intrinsic pontine glioma: A systematic review and meta-analysis. Medicine (Baltimore). 2020 Oct 16;99(42):e22721. doi: 10.1097/MD.0000000000022721. PMID: 33080729; PMCID: PMC7571996. - Kim HJ, Suh CO. Radiotherapy for Diffuse Intrinsic Pontine Glioma: Insufficient but Indispensable. Brain Tumor Res Treat. 2023 Apr;11(2):79-85. doi: 10.14791/btrt.2022.0041. PMID: 37151149; PMCID: PMC10172015. Keywords: DIPG, reirradiation, hypofractionation

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Poster Discussion Rhabdomyosarcoma of the Head & Neck Region: Long term Outcomes & Prognostic factors Siddhartha S Laskar 1 , Subramanya Adiga 1 , Ajay Sasidharan 2 , Nehal R Khanna 1 , Jifmi J Manjali 1 , Badira Parambil 3 , Girish Chinnaswamy 3 , Maya Prasad 3 , Venkata Gollamudi 3 , Sajid Qureshi 4 , Mukta Ramadwar 5 , Poonam Panjwani 5 , Sneha Shah 6 , Akshay Baheti 7 , Vasundhara Patil 7 , Mary A Muckaden 8 , Purna Kurkure 8 1 Radiation Oncology, Tata Memorial Centre, Mumbai, India. 2 Radiation Oncology, Amrita Hospital, Kochi, India. 3 Paediatric Oncology, Tata Memorial Centre, Mumbai, India. 4 Surgical Oncology, Tata Memorial Centre, Mumbai, India. 5 Pathology, Tata Memorial Centre, Mumbai, India. 6 Bio imaging, Tata Memorial Centre, Mumbai, India. 7 Radiodiagnosis, Tata Memorial Centre, Mumbai, India. 8 Palliative Care, Tata Memorial Centre, Mumbai, India

Purpose/Objective: To analyze the outcomes of patients with non-metastatic H&N rhabdomyosarcoma treated with multi-agent chemotherapy with radiotherapy and/or surgery. Material/Methods: Medical records of 156 patients with non-metastatic H&N rhabdomyosarcoma treated between 2007 and 2021 in a single institution were analyzed.