S2804
RTT - RTT contouring, target definition, and treatment planning
ESTRO 2026
Automated IMPT planning for HNC demonstrated clinically acceptable robustness and plan quality comparable to manual optimization. NTCP differences were generally small; however, in a subset of patients with Δ NTCP values near the 5% clinical selection threshold, these differences could potentially alter treatment modality selection. Automated proton planning may thus streamline workflows while preserving clinical validity, provided that borderline cases are individually assessed. References: 1 Van den Bosch L, van der Schaaf A, van der Laan HP, Hoebers FJP, Wijers OB, van den Hoek JGM, et al. Comprehensive toxicity risk profiling in radiation therapy for head and neck cancer: A new concept for individually optimised treatment. Radiother Oncol. 2021;157:147-54. Keywords: proton, treatment planning, script What is the impact of the dose received by the bone marrow on hematological toxicity during concurrent chemoradiotherapy in rectal cancer ? Yasmin AZARKANE, Sami AMRAOUI, Wafaa MERSSETTI, Soukaina MORCHID, Nabila SELLAL radiotherapy-oncology, CHU Mohammed VI, tangier, Morocco Purpose/Objective: Radiotherapy plays a central role in the multimodal management of locally advanced rectal cancers. In adults, nearly half of the body's bone marrow (BM) is located in the pelvic region, particularly in the flat bones of the axial skeleton and the pelvic bones. The objective of this study is to evaluate the dose received by the bone marrow during pelvic irradiation in patients with rectal cancer and to assess its impact on Digital Poster 4991
respectively. For three patients, the Δ NTCP for dysphagia in the automated and manual IMPT plans was close to the 5% clinical selection threshold, with only the manual plans exceeding this criterion (4.8% vs 5.1%, 4.1% vs 6.7%, and 4.9% vs 5.1%, respectively).
hematological toxicity Material/Methods: We conducted a retrospective study at the
radiotherapy department of Mohamed VI University Hospital in Tangier between April2017 and July2025, including patients with non-metastatic rectal cancer treated with concurrent chemoradiotherapy according to the PRODIGE 23 protocol (CRC). Clinical and biological data were extracted from the hospital information system. BM was delineated in all patients according to RECORAD 2022 recommendations (L4,L5, lower pelvis extending from the inferior border of the ischium to the acetabular roof, both iliac bones, and femoral heads). Patients with abnormal complete blood count before the start of CRC were excluded.
Conclusion:
Made with FlippingBook - Share PDF online