ESTRO 2025 - Abstract Book

S731

Clinical - CNS

ESTRO 2025

3805

Digital Poster Comparative Analysis of and Clinical Outcomes in Adult Craniospinal Irradiation: Tomotherapy Versus Published Data on Tomotherapy and Proton Therapy José J Cantillana, María Isabel M.I. García, Sara S Pérez, Arancha G Gallego, Susana S Sánchez, Carlota C Cascajares, Mariela M Rojas, Sofía S Merino, Irene I Ávila, Peppa P Abelairas, Clara C Caballero, María Ángeles M.A. Ruiz Radiation Oncology, Hospital Universitario Puerta de Hierro, Madrid, Spain Purpose/Objective: The aim of this study is to evaluate and compare the clinical and dosimetric results in adult patients undergoing craniospinal irradiation (CSI) treated in our centre with helical tomotherapy (HT) units, compared to the clinical results published for proton therapy (PT) and helical tomotherapy (HT) techniques. Material/Methods: Clinical and dosimetric data from the first treatment phase of 39 adult-patients with ICS (19women, 20men, mean age 33.6years) treated with HT have been collected and compared with data published to date. Twenty-six of them received doses between 36-40Gy and the other thirteen 23.4Gy. Results: In the analysed sample of adult patients undergoing craniospinal irradiation (CSI) with helical tomotherapy (HT), toxicity was found to be comparable to values published in previous studies for similar treatments. The dose administered varied between 23 and 54 Gy, with a median dose of 36 Gy. In terms of side effects, gastrointestinal (GI) toxicity was mostly mild, being classified as grade 1 in 40% of patients, grade 2 in 30%, and grade 3 in 10%, while 20% had no GI toxicity. In addition, there was a low incidence of severe haematological effects, with 75% of patients having haemoglobin and platelet values at acceptable levels during treatment. Specifically, grade 1 haematological toxicity occurred in 25% of patients, grade 2 in 10%, and no cases of grade 3 or higher were observed. The most frequent diagnosis among patients was medulloblastoma, accounting for 43% of cases. Regarding oesophageal toxicity, the majority of patients had no significant oesophagitis, with 73% having no toxicity, 15% having grade 1 oesophagitis, and 12% having grade 2 oesophagitis. Progression-free intervals during follow-up ranged from 6 to 144 months, with a mean of 70 months and a median of 67 months. These results indicate significant clinical stability in the majority of patients treated with HT.