ESTRO 2021 Abstract Book

S87

ESTRO 2021

Abstract Text Target delineation in upper gastrointestinal malignancies is crucial, but still hampered by variability. Variability in delineations will lead to differences in irradiated volumes and eventually in clinical outcome. A key issue remains the CT based anatomy of upper GI lymph-nodal stations. Several guidelines (GL) are available in literature but are not consistent in their recommendations on anatomical boundaries. ESTRO-ACROP endorsed a project to provide GL for delineation of lymph-nodal stations involved in upper gastrointestinal malignancies for preoperative (or definitive) setting and selected a working group for this task. This talk provides the outcome of this process and delivers the main key points on: (1) anatomical/radiological boundaries for each lymph-nodal station; (2) a CT-based atlas with delineation of all the lymph-nodal areas in each slice (validated by the working group); (3) an online interactive case based on the FALCON EduCase platform enabling ROs to individually train on this delineation 1 University Hospital Erlangen, Dept. of Radiation Oncology , Erlangen, Germany; 2 La Fe University and Polytechnic Hospital, -, Valencia, Spain; 3 University Medical Center Utrecht, Department of Radiation Oncology, Utrecht, The Netherlands Abstract Text GEC-ESTRO has been and is being very active in the production of recommendations, with the aim of standardizing the clinical practice as well as incorporating and adapting the state of the art in Brachytherapy in Europe and beyond. By the end of 2020, a total of twenty-three GEC-ESTRO guidelines/recommendations had been published. Especially productive was 2017 with three of them and in the years 2010, 2014, 2016 and 2018 two GEC-ESTRO guidelines per year have been published. Guidelines addressed different tumor sites (prostate, gyn, head&neck, breast, bladder, skin) and different physical aspects (treatment planning/applicator reconstruction, source calibration, uncertainties, robotic brachytherapy..). These guidelines have been published in R&O or Med Phys, range of citation rate was still low, logically, for the most recently published guidelines but up to > 870 and > 950 for two gyn brachy guidelines from 2005 and 2006. Citation rates for prostate (2005) and breast (2010) guidelines were > 200 and >370 respectively. We conclude that GEC-ESTRO guidelines are very well acknowledged and then very useful in the brachytherapy community. A good part of the recommendations produced have been in collaboration with other societies or associations in order to harmonize and establish common criteria worldwide in brachytherapy. In some cases, recommendations from other societies have been “endorsed” but in the majority of cases the collaborations have been carried out through “joint” projects. ABS, EAU/EORTC, ESGO and AAPM are important examples of these collaborations, existing with some of them well established agreements). In early 2020 GEC-ESTRO has launched an initiative for improving guideline writing, with the goal of developing a guideline collection that represents state-of-the-art brachytherapy for all sites of brachy including specific aspects for imaging and physics. During guideline writing should be taken into account: relevance for the brachy community, update/supplement to existing guideline/recommendation, relevance beyond brachytherapy, joint guidelines with other scientific societies, guidelines for new tumor sites or techniques, etc. GEC-ESTRO is proud of the previous number as well of Clinical as of Physical brachytherapy-related guidelines and of their international and multidisciplinary value RTT guidelines describe (parts of) the clinical workflow. Are evidence based and practice based and inform RTTs about the prescribed standards. The aim of these guidelines is to improve the quality of the treatment. Finally, guidelines enable the process of evaluating and improving the workflow in the department. RTT guidelines: Where do we stand The first ESTRO ACROP RTT guideline published in 2017 described the use of shielding masks: “ESTRO ACROP guidelines for positioning, immobilisation and position verification of head and neck patients for radiation therapists” [1]. From this RTTs became aware of the key issues concerning this topic. This guideline was downloaded 18.522 times since then. Indicating there is a need for these practical guidelines. At the moment the RTT committee is working on guidelines about the positioning and position verification of patients treated for pelvic and breast cancer. Also skin care guidelines will be developed. RTT guidelines: Where do we want to be in 2025? Having produced ESTRO ACROP RTT guidelines based on an overview which guidelines are needed most. RTT guidelines: What do we need? Amongst others, a multi professional radiotherapy team needs to be involved in the development of guidelines. As we have to work together as a team of professionals to ensure best practice for our patients. We need an overview of the lacks of evidence to define the specific topics were research is needed to improve the standard of care even further. And finally, we need to evaluate the efficacy of the RTT guidelines. [1] https://www.sciencedirect.com/science/article/pii/S2405632416300191 SP-0126 Guideline development GEC ESTRO V. Strnad 1 , J. Perez-Calatayud 2 , I. Jurgenliemk-Schulz 3 SP-0127 Guideline development RTT M. Mast 1 1 Haaglanden Medical Center, Radiotherapy, Leidschendam, The Netherlands Abstract Text RTT guidelines: Why

SP-0128 Guideline development clinical DIVERSA - Glio, breast, skull base