ESTRO 37 Abstract book

S286

ESTRO 37

Abstract text Synopsis

necessity and the role of RTTs within this framework is unquestionable. SP-0543 Innovative education to cover the gaps J.G. Eriksen 1 1 Aarhus University Hospital, Dept. of Experimental Clinical Oncology, Aarhus, Denmark Abstract text Radiation therapy is one of the most cost-effective ways to treat cancer - both in a curative and a palliative setting. Despite this, the gap in radiation oncology capacity is still noticeable especially in low- and middle- income countries where a rapid rise in the incidence of cancer cases is a serious problem. The urgent need for radiotherapy resources in terms of bunkers and megavoltage machines is important, but equally important is the lack of properly educated health care professionals. This includes not just medical doctors, but also medical physicists, radiation therapists and nurses, as well as other supporting health care personnel. A possible way to cover these knowledge gaps are to evolve how we deliver the education and the presentation will discuss current initiatives. First of all, it is important to recognise that although differences exists around the world, the minimum competences of a radiation oncologist, a medical physicist or an RTT should basically be the same and therefore there is a need to define a common frame: an international minimum standard through globally accepted curricula. Secondly, there is a need to critically evaluate how we deliver education today. Most often, postgraduate education are performed as live events in courses or at conferences, but that is not necessarily cost-effective. Therefore, there is a need to explore other ways of gaining knowledge without compromising on the quality of the teaching. This is not a trivial task and initiatives are multiple. One typical example is pure one-way online teaching. Although having the benefit of an asynchronous format one-way online learning rarely meet the needs for interactivity, reflection and application to practice. For that, more blended approaches of online and live teaching seems to be more attractive for obtaining not just knowledge but also skills. Examples of such activities will be presented as well as the long-term retention rate will be discussed. Finally, closing educational gaps effectively also requires tailored initiatives focused for the end-users, teaching empowerment including “train the trainers”-programs, exchange programs and long-term strategies involving a multiple of stakeholders. Some of these initiatives will be highlighted in the presentation. SP-0544 Dual energy CT: Benefits for proton therapy planning and beyond C. Richter 1 , P. Wohlfahrt 1,2 , C. Möhler 3,4 , S. Greilich 3,4 1 OncoRay - National Center for Radiation Research in Oncology, High Precision Radiotherapy Group, Dresden, Germany 2 Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany 3 German Cancer Research Center DKFZ, Division of Medical Physics in Radiation Oncology, Heidelberg, Germany 4 Heidelberg Institute for Radiation Oncology HIRO, Division of Medical Physics in Radiation Oncology, Heidelberg, Germany Joint Symposium: ESTRO-ESR: New imaging approaches for radiotherapy

For about a decade, dual-energy CT (DECT) has been clinically available, mainly for radiology applications. In contrast, in the field of radiotherapy DECT has gained relevant interest over the last few years and here clinical use is still far away from being clinical standard. In this lecture benefits of DECT for radiotherapy applications will be discussed. The focus will be on application for treatment planning in proton therapy, namely the individual prediction of tissue’s stopping power relative to water (SPR) as an alternative to the standard approach using a generic look-up table (HLUT). The manifold information gathered by two CT scans with different X-ray spectra allow for a patient-specific and direct calculation of relative electron density and SPR [1,2]. This enables the consideration of intra- and inter-patient variabilities in CT-based SPR prediction and ultimately a more accurate range prediction. The talk will cover the validation of the SPR prediction accuracy in realistic ground-truth scenarios [3,4], the investigation of clinical relevant differences between the DECT-based and the standard HLUT-based SPR prediction in clinical patient data [5] as well as the status of its clinical implementation [6]. Furthermore, additional applications in radiotherapy, e.g. for photon treatment planning, delineating and material differentiating will be briefly discussed. References [1] Möhler C, Wohlfahrt P, Richter C, Greilich S. Range prediction for tissue mixtures based on dual-energy CT. Phys Med Biol 61:N268-N275, 2016. [2] Möhler C, Wohlfahrt P, Richter C, Greilich S. Methodological accuracy of image-based electron- density assessment using dual-energy computed tomography. Medical Physics 44:2429-2437, 2017. [3] Möhler, C, Russ, T, Wohlfahrt P, Elter, A, Runz, A, Richter, C, Greilich S. Experimental verification of particle-range prediction in biological tissue by single- and dual-energy computed tomography. Phys Med Biol, accepted. [4] Wohlfahrt P, Möhler C, Richter C, Greilich S. Evaluation of stopping-power prediction by dual- and single-energy computed tomography in an anthropomorphic ground-truth phantom. IJROBP 100: 244-253, 2018. [5] Wohlfahrt P, Möhler C, Stützer K, Greilich S, Richter C. Dual-energy CT based assessment of patient-specific range prediction uncertainty in proton treatment planning. Radiother Oncol 125: 526-533, 2017. [6] Wohlfahrt P, Möhler C, Hietschold V, Menkel S, Greilich S, Krause M, Baumann M, Enghardt W, Richter C. Clinical implementation of dual-energy CT for proton treatment planning on pseudo-monoenergetic CT scans. IJROBP 97:427-434, 2017. SP-0545 Ultrasound imaging in radiotherapy: ‘Old’ technology with new applications in RT? E. Harris 1 1 The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Radiotherapy and Imaging, Sutton, United Kingdom Abstract text Medical ultrasound was first introduced in the 1940’s and has become a powerful diagnostic tool throughout the world. Its real-time, soft-tissue imaging capability and non-ionizing nature have contributed to its ubiquitous use in disease diagnosis and image guidance in interventional and surgical procedures. Ultrasound guidance of radiotherapy is a relatively new field with the first commercial systems becoming available in the late 1990’s. Despite possessing clear benefits for imaging a variety of tumour sites, challenges associated with