ESTRO 2022 - Abstract Book

S9

Abstract book

ESTRO 2022

The advantages of a better RSP prediction and therefore decreased proton range uncertainty have direct consequences to the patient. Comparisons of proton treatment plans calculated on SECT vs DECT show clinically relevant range and dose differences in head/neck and pelvic patients, adults as well as children. Consequently, the reduction of the treatment margins from the conventional 3.5% range uncertainty to 2% is considered by proton centres using DECT for treatment planning. Despite the clinical availability of dual-energy CT and the vast literature showing the advantages of DECT over SECT in radiotherapy planning, the full clinical translation still faces its challenges. Those challenges include the technical implementation of DECT algorithms into the clinical workflow, the lack of recommendations concerning the safe application of DECT-derived quantities, and the standardisation of DECT calibration and validation across clinics. In this short summary, we will explore the most recent clinical findings in DECT for radiotherapy, with a focus on applications to protons. We will discuss the challenges involved in clinical translation and future directions. 1 Department of Radiation Oncology (MAASTRO), GROW – School for Oncology, Maastricht University Medical Centre+, Maastricht, The Netherlands; 2 Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; 3 Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA, USA., Now with Siemens Healthineers, Forchheim, Germany Abstract Text In this presentation, we will give a summary of the ESTRO Physics Workshop on Clinical Translation of CT Innovations in Radiation Oncology as well as the initiatives inspired by the workshop. We organised this workshop as an interactive gathering of CT enthusiasts from clinics, research institutes and industrial partners to share their experiences, challenges and desires. The main aim was to facilitate translation of CT innovations into the clinic, by establishing collaborations between CT experts across institutes, and by specifying technical requirements and establishing standardisation guidelines. In total, 25 active participants joined our two-part online physics workshop. The two parts took place in June and October 2021. The workshop was complemented by monthly meetings in smaller focus groups in the interim period to foster in-depth discussions and inter-institutional exchange on conventional and spectral CT for dose calculation and organ and tumour segmentation, as well as CT commissioning and quality assurance. During the online workshop, we had tailored keynote presentations, vision talks and expert statements which were followed by panel discussions, as well as topical deep-dive sessions. These stimulated brainstorming within the group. The use of pre-structured interactive whiteboards enabled all participants jointly to collect ideas, questions, comments and recommendations simultaneously. Online questionnaires and live polls were used to determine trends in real-time and to kick-off controversial discussions. The change in the workshop structure, in regards to the previous ESTRO Physics Workshops, from a one-time event to a self-evolving working group over months framed by two multi-day workshops helped to build close personal connections and has already led to the establishment of many clinical collaborations among institutions on CT implementation and commissioning. We wanted to continue these joint efforts to establish a supportive and collaborative framework among clinics to ease the widespread clinical translation of CT innovations. Therefore, we have decided to drive this initiative through formation of a CT working group in combination with a data-sharing hub and webcast series. Our workshop clearly unveiled participants’ wishes to establish an open exchange of clinical CT experiences and commissioning data, supplemented with how-to recommendations and guidelines. We are currently in the process of fine-tuning the overall concept of this initiative. In the meanwhile, one of the first outcomes of this workshop is now being finalised; together with the European Particle Therapy Network (EPTN), we are developing a detailed step-by-step guideline on CT calibration for proton therapy. These first outcomes and the further development of these initiatives will be the main focus point of this presentation, which we hope will encourage even more people to get as excited about CT as we are, and to join our further efforts. SP-0035 Clinical translation of CT innovations – Report from the 2021 physics workshop V. Taasti 1 , T. Bortfeld 2 , P. Wohlfahrt 3