ESTRO 2020 Abstract Book

S1078 ESTRO 2020

exhibited a strong concordance with the consensus working group. Conclusion The ‘gold standard’ IGRT assessment training package has shown great potential in providing an efficient method of IGRT training. The training package is thought to be easy to use, enhances the effectiveness of IGRT training and improves confidence in trainees IGRT abilities. The semi- automated assessment method provides consistency in training irrespective of individual assessor subjective bias. Future work will include continuing the evaluation of the 6 produced SSAPs over a larger number RTTs, as well as developing further SSAPs including plan selection for adaptive strategies. There is the potential to develop some machine learning capabilities to further semi-automate free text sections within the SSAPs. PO-1937 A new software for advanced education and assessment of tumour volume delineation in radiotherapy C. Piazzese 1 , E. Evans 2 , E. Spezi 1 , J. Staffurth 2 , S. Gwynne 3 1 Cardiff University, School of Engineering, Cardiff, United Kingdom ; 2 Velindre Cancer Centre, Clinical Oncology, Cardiff, United Kingdom ; 3 South West Wales Cancer Centre, Clinical Oncology, Swansea, United Kingdom Purpose or Objective Accurate delineation of target volumes and organ-at-risk (OAR) are necessary with modern radiotherapy (RT) techniques to avoid over or under-treatment. However, this process is error-prone and can be associated with intra/inter-observer variations 1 . The ARENA project aims to support ongoing continuous professional development and target volume delineation (TVD) training for UK clinical oncology trainees and consultants using tumour site-specific TVD instructional and corresponding outlining modules. Here we present and describe the ARENA training software developed to help and improve the quality of TVD through qualitative and quantitative feedbacks. Material and Methods The ARENA software was developed using MATLAB (The Mathworks,Inc.). The CERR 2 package was incorporated in the ARENA software to import the RT treatment planning information. The ARENA software includes the follow components: a) educational material with detailed RT planning guidance including sites of common TVD errors; b) a user-friendly interface to import outlines for evaluation; b) a multi-modality image viewer for scans and outlines in different anatomical planes; c) an analysis package for processing the outlines imported to produce quantitative and qualitative feedback; e) a structured report package to generate an exportable document with a personalised summary of the quantitative and qualitative feedback of the trainee’s performance. Results Pilot clinical sites currently integrated in the ARENA software are oesophagus and prostate. User volumes are compared to a pre-defined reference volume. Morphologic information and 2D/3D Jaccard conformity index are provided as quantitative feedback. Qualitative evaluation includes visual display of over and under contoured area with a 'red flag' for inappropriately contoured volumes, user outline vs. reference volume, maximum/minimum acceptable volumes. Figure 1 shows an example of three different qualitative evaluations of a trainee's performance in the ARENA software.

Figure 1. Qualitative evaluations of the trainee's performance in the ARENA software: over/under contoured regions (top left), max/min acceptable volumes (top right) and user outline vs. reference volume and OARs plus a 'red flag' for volumes inappropriately contoured (bottom). Conclusion The ARENA software aims at facilitating a standardised approach for TVD training. Two tumour site-specific TVD instructional and outlining modules have already been developed and more (breast, lungs, head & neck) are going to be integrated in the future. The software is easy to use, and it quickly evaluates the trainee's performance using different quantitative and qualitative feedbacks through the user-friendly viewer or a personalised and exportable report. References : 1. Gwynne S et al. Toward semi-automated assessment of target volume delineation in radiotherapy trials: the SCOPE1 pretrial test case. Int J Radiat Oncol Biol Phys, 2012 PO-1938 Implementation of Stereotactic Radiosurgery (SRS) for brain metastases. A. Nielsen 1 , M.B. Andersen 1 1 University Hospital Herlev, Radiotherapy department, Herlev, Denmark Purpose or Objective Stereotactic Radiosurgery (SRS) workflow optimization for the treatment of brain metastases. Material and Methods A multidisciplinary working group consisting of physicians, physicists and Radiotherapy technicians (RTT's) was in September 2018 introduced to HyperArc from Varian and ExacTrac from Brainlab. Prior to implementation of SRS, ExacTrac was already installed in the department, but not yet in clinical use. The physicist group found, that ExacTrac could be used as an independent system for patient positioning and verification before and during treatment. Therefore, the starting point was to combine Cone beam computed tomography (CBCT) and MV-images with ExacTrac. The group was ready to receive the first patient for SRS treatment October 11. 2018 on a Varian Truebeam accelerator equipped with a Millennium 120 multileaf collimator (MLC). 2. Deasy JO et al. CERR: a computational environment for radiotherapy research. Med Phys, 2003