ESTRO 2025 - Abstract Book

S3606

Physics - Quality assurance and auditing

ESTRO 2025

Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden, Germany. 5 Department of Radiation Oncology (Maastro), Maastricht University Medical Centre+, Maastricht, Netherlands. 6 Department of Oncology, KU Leuven - University of Leuven, Leuven, Belgium. 7 Department of Radiation Oncology, University Hospitals Leuven, Leuven, Belgium. 8 Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland. 9 Department of Radiation Oncology, University Medical Center Groningen, Groningen, Netherlands. 10 Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark. 11 EBG, MedAustron GmbH, Wiener Neustadt, Austria Purpose/Objective: To present results from the trial radiotherapy quality assurance (RTQA) programme of the centres involved in the randomised phase-III PROTECT-trial, comparing neoadjuvant proton or photon chemoradiotherapy in patients with locally advanced oesophageal cancer. The pre-trial RTQA programme is illustrated in Figure 1 and consists of benchmark target and organ at risk (OAR) delineations as well as treatment planning cases, a facility questionnaire and beam output audits. Continuous on trial RTQA with individual case review (ICR) of the first two patients and every fifth patient at each participating site is performed. Patient specific QA is mandatory for all patients. On-site visits (Figure 2) are scheduled after the inclusion of the first two patients at two associated proton therapy (PT) and photon therapy (XT) sites. Workshops are arranged annually for all PROTECT participants. Here, the status of the trial is presented by the RTQA group and topics on e.g. adaptive strategies, challenging cases and translational studies can be discussed. The workshop is arranged by the RTQA group. Material/Methods: