ESTRO 2025 - Abstract Book

S1615

Clinical – äediatric tumours

ESTRO 2025

References: 1) Lu, V. M., Welby, J. P., Mahajan, A., Laack, N. N., & Daniels, D. J. (2019). Reirradiation for diffuse intrinsic pontine glioma: a systematic review and meta-analysis. In Child’s Nervous System (Vol. 35, Issue 5, pp. 739–746). Springer Science and Business Media Deutschland GmbH. https://doi.org/10.1007/s00381-019-04118-y 2) Lassaletta, A., Strother, D., Laperriere, N., Hukin, J., Vanan, M. I., Goddard, K., Lafay-Cousin, L., Johnston, D. L., Zelcer, S., Zapotocky, M., Rajagopal, R., Ramaswamy, V., Hawkins, C., Tabori, U., Huang, A., Bartels, U., & Bouffet, E. (2018). Reirradiation in patients with diffuse intrinsic pontine gliomas: The Canadian experience. Pediatric Blood and Cancer , 65 (6). https://doi.org/10.1002/pbc.26988

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Digital Poster The impact of craniospinal radiotherapy on therapeutic efficacy and toxicity in paediatric medulloblastoma Fatima-Zohra ZAANOUN, Bilal Elalaoui, Samia Khalfi, Kaoutar Soussy, Wissal Hassani, Fatima Zahraa Farhane, Zenab Alami, Touria Bouhafa Radiotherapy Brachytherapy Department, CHU HASSAN II, Fez, Morocco Purpose/Objective: The aim of our study was to evaluate the clinical outcome and toxicity of craniospinal irradiation with intensity modulated conformal radiotherapy for paediatric medulloblastoma. Material/Methods: Between January 2015 and January 2020, 51 children underwent surgery for medulloblastoma followed by radiotherapy at the Radiotherapy-Brachytherapy departement of the Hassan II University Hospital in FES. For 49 of them, the therapeutic strategy included chemotherapy. Tumour recurrence was observed in 13 children after an average of 38 months, with the posterior cerebral fossa being the main site of recurrence.Progression was marked by bone and lymph node metastatic relapse in 5 children. Late toxicity was alopecia in 20% of patients, asthenia in 65%, cerebellar syndrome in 38.5%, cognitive impairment in 57.4%, hearing impairment in 21% and amenorrhea in 8% of patients. The prognostic factors found which may explain these results in our study are: the existence of a postoperative residue, cerebrospinal fluid positivity, metastatic status and high-risk medulloblastoma. Analysis of these disappointing results compared with subsequent randomised studies led us to explain them by: the high percentage of high-risk medulloblastomas in this cohort (60% compared with 14% to 37% depending on the series); the number of children under 5 years of age (23 children) for whom the prognosis is less favourable; and the duration of the study, which covered a wide range of therapeutic strategies. Conclusion: Medulloblastoma is a well-known paediatric cancer for which new therapeutic perspectives are emerging, including strategies adapted to the risk of progression, chemotherapy options with or without irradiation, specific therapeutic targets and advances in irradiation techniques. Results: The average age of the children included was 6 years old.

Keywords: Craniospinal radiotherapy , efficacy , toxicity