ESTRO 2025 - Abstract Book

S3601

Physics - Quality assurance and auditing

ESTRO 2025

2. Malatesta T et al., Patient specific quality assurance in SBRT: a systematic review of measurement-based methods, Phys Med Biol. 2023 Oct;68(21). 3. Hoffmann L et al., Validation of the Acuros XB dose calculation algorithm versus Monte Carlo for clinical treatment plans, Med Phys. 2018 Jun;45(8). 4. Hernandez V et al., Comparison of complexity metrics for multi-institutional evaluations of treatment plans in radiotherapy, Phys Imaging Radiat Oncol. 2018 Feb;5. 5. Masi L et al., Robotic MLC-based plans: A study of plan complexity, Med Phys. 2021 Mar;48(3).

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Digital Poster Establishing a dosimetric end-to-end test in proton therapy

Yannick Joppien 1 , Luisa Parschat 1 , Jörg Wulff 1 , Melanie Vüllings 1 , Claus Maximilian Bäcker 1 , Beate Timmermann 2 1 West German Proton Therapy Centre Essen (WPE), University Hospital Essen, Essen, Germany. 2 Department of Particle Therapy, West German Proton Therapy Centre Essen (WPE), University Hospital Essen, Essen, Germany Purpose/Objective: To utilize the full potential of PBS proton therapy, all machine parameters involved and intermediate steps in the treatment must be checked carefully [1]. An end-to-end (E2E) test, which mimics a complete patient treatment from start to finish, is typically performed annually and after initial commissioning of a treatment room. Although an E2E test is generally defined in DIN6864-1 [2], there are no further details provided regarding the procedures of this test and the choice of phantom. Purpose of this work was the development of a straightforward E2E test procedure for periodical QA in proton therapy. inhomogeneous geometry of the Gammex AED head phantom with different inserts [3]. A robustly optimized 3 field SFUD treatment plan (Fig. 1) was modelled in RayStation (version 12A SP1), deliberately passing fields through inhomogeneous parts. The single fields covered different ranges and gantry angles, with and without range shifter. The phantom was initially setup by room lasers and corrected by orthogonal X-ray imaging (2D/3D matching). The setup and irradiation was tested in every treatment room of WPE using an IBA ProteusPlus system (Fig. 2). Dose was measured with an IBA CC04 ionization chamber in a dedicated holder at various locations inside the Gammex AED head phantom. Material/Methods: A test was defined that contains the complete workflow from CT imaging to beam delivery based on