ESTRO 2024 - Abstract Book

S2983

Interdiscplinary - Other

ESTRO 2024

[3] Rotondi MA, Donner A. A confidence interval approach to sample size estimation for interobserver agreement studies with multiple raters and outcomes. J Clin Epidemiol. 2012;65:778-84. 10.1016/j.jclinepi.2011.10.019.

[4] Team RC. R: A language and environment for statistical computing. R Foundation for Statistical Computing; 2022.

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[6] Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977;33:159-7

3140

Digital Poster

Clinical implementation of online Daily Adaptive Proton Therapy (DAPT): First in human treatment

Francesca Albertini 1 , Miriam Vazquez 1 , Katarzyna Czerska 1 , Ilija Andaca 1 , Rico Besson 1 , Anne Sophie Bogaert 1 , Evangelia Choulilitsa 1,2 , Jan Hrbacek 1 , Annick Kurt 1 , Sisse Jakobsen 1 , Dominic Leiser 1 , Alexander Mayor 1 , Michael Matter 3 , Gabriel Meier 1 , Andrè Nanz 1 , Lena Nenoff 3 , David Oxley 1 , Dorota Siewert 1 , Andreas Smolders 1,2 , Hubert Szweda 1 , Michelle van Heerden 1 , Carla Winterhalter 1 , Antony John Lomax 1,2 , Damien Charles Weber 1,4,5 1 Paul Scherrer Institute (PSI), Center for Proton Therapy, Villigen, Switzerland. 2 ETHz, Department of Physic, Zurich, Switzerland. 3 Formerly affiliated with PSI, Center for Proton Therapy, Villigen, Switzerland. 4 University Hospital Zurich, Department of Radiation Oncology, Zürich, Switzerland. 5 Inselspital, Department of Radiation Oncology, Bern, Switzerland

Purpose/Objective:

The development and clinical implementation of an on-line (daily) adaptive treatment workflow for proton therapy (DAPT) has been pursued at our institute since 2015, with a focus on simplicity, speed, and minimal disruption to the conventional workflow. In 2020, we demonstrated the feasibility of this approach using an anthropomorphic phantom and showed that a DAPT workflow would not necessarily increase treatment time. Here, we report on what we believe is the world’s first clinical application of DAPT to a human patient.

Material/Methods:

A patient with a solitary fibrous tumour WHO grade I in the parieto-occipital region was treated with the in-house developed @DAPT software, which supports an ultra-fast DAPT workflow. This starts with the preparation of a template plan which is initially optimized on the pre-treatment images. For this first case, a 2-field IMPT plan (right and left posterior oblique fields), was optimized to deliver 9GyRBE as a boost series to the high-risk target volume. Daily images were obtained with an in-room CT using a low-dose CT protocol optimized to minimize imaging dose. All structures were rigidly propagated from the pre-treatment plan to the daily CT image. All daily plans were then fully re-optimized with the patient on the couch to generate a daily plan, with all clinical goals and DVHs being assessed and compared to the template plan. Rigorous quality assurance checks, including independent dose calculations, were performed prior to delivery. Dosimetry accuracy was assessed post-treatment by reconstructing the delivered dose recorded in the log-files onto the daily CT images and by performing patient