ESTRO 2025 - Abstract Book

S2909

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2025

Conclusion: Our results show that a potential reduction of the pharyngeal dose in the treatment of head and neck cancers is possible without negative dosimetric effects to the surrounding OARs without compromising the target coverage. We plan to initiate a clinical trial to test the clinical relevant and measurable benefit of this advanced treatment planning technique.

Keywords: head and neck, pharyngeal sparing

References: [1] Paetkau O et al., Pharyngeal Constrictor DoseeVolume Histogram Metrics and Patient-Reported Dysphagia in Head and Neck Radiotherapy, Clin Oncol (R Coll Radiol). 2024 Mar; 36(3):173-182. [2] Margalit DN et al., Radiation Therapy for HPV-Positive Oropharyngeal Squamous Cell Carcinoma: An ASTRO Clinical Practice Guideline, Pract Radiat Oncol. 2024 Sep-Oct; 14(5):398-425.

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Digital Poster 4D-CT vs. DIBH-CT: CTV variability and dosimetric impacts in photon and proton treatment planning for gastric MALT Giovanni Pirrone 1 , Fabio Matrone 2 , Alessandra Donofrio 2 , Maurizio Mascarin 2 , Andrea Dassie 1 , Paola Chiovati 1 1 Medical physics, Centro di Riferimento Oncologico, Aviano, Italy. 2 Radiation Oncology, Centro di Riferimento Oncologico, Aviano, Italy Purpose/Objective: Respiratory and organ motion management during RT for patients with gastric mucosa-associated lymphoid tissue lymphoma (MALT) can reduce treatment uncertainties [1]. This analysis evaluates the impact of pre-RT simulation techniques, such as 4D-CT and DIBH-CT, on inter-operator variability in target contouring. It further investigates the