ESTRO 2020 Abstract Book

S7 ESTRO 2020

appointed to hospital positions happened in Munich and in London in 1912 and 1913 respectively. Ever since, Medical Physicists have largely contributed in the technological and clinical advances of radiation therapy, and constitute a key group with a central role within the multidisciplinary approach of oncological care. Today, Medical Physicists are, more in general, responsible for guaranteeing a safe and optimal use of radiation in medicine; their flexibility, intrinsic translational character and their unique skills represent an important added value in the scientific and clinical contexts within the rapidly changing scenario of radiation oncology of current times. The rapid change of radiation oncology as a relevant branch of precision oncology together with the rapid growth and spread of high-tech radiotherapy and the consequent increased commitment of medical physicists opened a debate in the radiation oncology physics community regarding the redefinition of roles and responsibilities of medical physics in this new scenario. This debate should focus on the new scientific challenges to be faced in Radiation Oncology and on how medical physicists could contribute to find solutions. Then, in 2014 a task group on the “Future of Medical Physicists in Radiation oncology” (FUTURE_ESTRO) was created by the ESTRO physics committee. This initiative was in part inspired by the one represented by the AAPM Future task group in the USA. The mandate of both groups is to develop strategies to prepare medical physicists for future roles and responsibilities in clinical practice, research, product development, and education. The future group, acknowledging the inseparability between clinical service and research, wants to increase awareness of the importance of the research role of Medical Physicists. One of the actions proposed by the future task group was the organization of the think tank meeting on provocative questions for medical physicists in Radiation Oncology. This workshop, held in Budapest in November 2019, involved not only medical physicists but other in-field experts (radiation oncologists, biologists, RTTs) and out-of-field experts. The process for question selection started in January 2019. The question selection followed the following scheme, first a call to all medical physicists ESTRO members asking for challenging questions and to all in-field debaters was launched. Then, among the 108 collected questions/statements, four were selected following a two-step procedure (grouping them in 4 categories and then selecting the most provocative/relevant from each category). The four statements finally selected were: 1. Medical physicists will transform tumor target definition from an art to science 2. Medical physicist will drive development and implementation of artificial intelligence in Radiation Oncology 3. Medical physicists will substantially contribute to modeling biological effects in the era of personalized Radiation Oncology 4. Medical physicists will be leaders in the changing world of Radiation Oncology SP-0031 Medical physicists will be leaders in the changing world of Radiation Oncology C. Clark 1 , L. Muren 2 , N. Jornet 3 1 National Physical Laboratory, Medical Radiation Physics, Teddington, United Kingdom ; 2 aarhus University, Medical Physics, Aarhus, Denmark ; 3 hospital Sant Pau, Servei De Radiofísica I Radioprotecció, Barcelona, Spain Abstract text Medical Physicists are the guardians of quality and safety in radiation oncology, but this is not the only role they play. They are also, more importantly, disruptors. Historically, Medical Physicists have led on all main technological developments in Radiation Oncology. However, technology only serves a purpose if it addresses a clinical need. Technological development ad infinitum is

not needed, and time and resource should not be wasted on it. The future of Radiation Oncology will be in personalization. This will be achieved through individualized biological based decisions underpinned by robust models. These models will be developed through deep learning and data mining for which the standardization and creative development will be led by Medical Physicists. Hence, we will need synergy between Radiation Oncologists and Medical Physicists to lead the field together. To continue to be leaders, the responsibility is with the medical physicists themselves. The majority of clinical medical physicists are doing routine things. To change the culture to be innovative again we need to a) have the right leaders in the right position and b) have the right education and training to drive innovation. The fact that Radiation Oncology has worked so well in the past decades is because the Medical Physicists were part of the team; this is a key difference to other disciplines. The future role of the Medical Physicists could be in leadership of all technological innovations (in both soft and hard technologies) that will be introduced in the hospital ie the Medical Physicists will lead the clinical engineers, data scientists and biomedical engineers and guide them in asking the right questions. Different disciplines in Radiation Oncology have different training, which give them different skills. Radiation Oncology needs all types of skill to effectively move the field forward and therefore the leadership needed to achieve this must be composed of Medical Physicists and other Radiation Oncology professionals. The key lies in choosing the right areas for each to lead in. In order to avoid a return to “interventional radiology” the changing world of Radiation Oncology will need Medical physicists to be leaders. Medical physicists will continue to lead in facilitation of implementation of technology and new techniques, including new directions such as AI. This has a wider reach in the hospital than in only in Radiation Oncology/Radiology/Nuclear medicine depts and therefore, for optimal effective leadership, Medical Physics departments should be independent from Radiation Oncology departments such that they have the ability to employ a greater variety of scientist. Furthermore, the independence of the Medical Physics department would better facilitate the ability to employ ‘out of field experts’ such a computer scientists and data scientists. In this way both Radiation Oncology and other medical disciplines would benefit from the inter- disciplinarity across the whole field of Medical Physics. SP-0032 Transforming CTV definition from an art to science T. Bortfeld 1 , C. Garibaldi 2 1 Mass. General Hospital, Radiation Oncology- Division Of Radiation Biophysics, Boston- Ma, Usa ; 2 istituto Europeo Di Oncologia, Medical Physics, Milan, Italy Abstract text Defining the clinical target volume (CTV) is a complex and challenging task that is traditionally owned by the radiation oncologists. Variations of CTVs drawn by different radiation oncologists for the same patient are substantial and vastly exceed the physical/technical uncertainties of targeting the radiation beam on a voxel in the patient. Input from physicists is needed to provide a more scientific basis for CTV definition. Research and development is required along at least three different directions. The first direction is the modeling of disease spread beyond the visible gross tumor volume, and infiltration of lymph nodes. Modeling the impact of multi- modality treatments including systemic therapies and immunotherapy, and their ability to take care of microscopic disease is also important. The second direction is to provide a probabilistic framework for CTV definition. The current binary CTV approach (100% tumor