ESTRO Annual Report 2020

The workshops are intended to complement the ESTRO school course on clinical particle therapy. The first workshop will be on brain and skull-base tumours and will be hosted by the Paul Scherrer Institute (PSI). It is tentatively scheduled for the autumn of 2021. WP4: Image guidance in particle therapy (IGPT) The aimof this working party is to gain insight into the current practice parameters of IGPT and to drive harmonisation through the establishment of body-site-specific consensus guidelines. The current standard of practice from the EU particle centres has been investigated, via detailed surveys specific to each body site. EPTN-WP4 will continue to focus on the completion of data collection from surveys and on the analysis of the data that have been collected already. The fourth annual workshop of the EPTN-WP4 was cancelled due to the Covid-19 pandemic and replaced by an online session that took place on 26 June 2020. The main topic of this meeting was the presentation and evaluation of four IGPT projects that have the potential tomake a significant impact on the particle therapy community. WP5: Treatment planning systems in particle therapy Treatment planning systems (TPSs) are essential for accurate and effective particle therapy and are an important part of the particle therapy workflow. In this working group, the aim is to review and to provide recommendations on numerous aspects of the treatment-planning process. The WP has formulated several sub-groups to cover the most important aspects of treatment planning systems: i. Collective TPS specifications; ii. Planning standards and case solutions; iii. TPS commissioning and validation; iv. Alternatives to patient-specific verifications; v. CT/ Hounsfield units calibration; vi. Robustness analysis; vii. The role of linear energy transfer (LET); viii. 4D planning. WP6: Radiobiology and relative biological effectiveness In February 2020, WP6 held a workshop in Manchester, UK, which was open to everybody with an interest in the clinical impact of the

relative biological effectiveness (RBE) in proton therapy and experimental particle radiobiology. A total of 44 participants from eight countries, who represented 13 centres, were present at the two-day meeting. WP6 and the coordinator of the INSPIRE WP9 on mathematical modelling and simulation are conducting a survey on current clinical practice regarding RBE in European proton therapy centres. The data will be published after they have been collected and analysed. WP7 : Health economy Health economic profiling of particle therapy is pivotal for its positioning within the portfolio of alternative radiotherapeutic modalities. However, so far, no assessment has been completed on a European level as it seems to be difficult to obtain the permission of centres to disclose the relevant financial and operational data. TheWP7 teamhas developed a methodological inventory that can be used for various assessments. This inventory can be adapted to national health technology assessment (HTA) requirements if needed. An online meeting of WP7 was held in December 2019 to investigate whether there was interest to collaborate on the evaluation of the ESTRO health economics in radiation oncology (HERO) costing model in the context of proton beam therapy (PBT). A first collaboration between ESTRO-HERO/ EPTN WP7 and the University of Manchester will be set up to evaluate the applicability of themodel to PBT, before enlarging the collaboration with other partners in EPTN WP7.

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