ESTRO 37 Abstract book

S174

ESTRO 37

while the lung was manually assigned in the MC interface.

therapists (RTTs) record and study the images acquired in order to correct the patient set-up. At UMC, RTTs are essential for the control and correction of the patient’s position before treatment. In fact, some RTTs are dedicated to patient positioning and verification, and I was able to watch them work, therefore, becoming more familiar with the role of an RTT in IGRT treatments. A new approach, based on on-line magnetic resonance imaging, is being developed at the UMC with a new hybrid MRI-guided linear accelerator (MRI-LINAC) and I had the great opportunity to approach to this new amazing project. Thanks to ESTRO mobility grant, I was also able to broaden my experience in some clinical procedures developed for on-line IGRT with MR images. Over my insightful two-week visit, I acquired practical skills in IGRT as applied to the techniques and protocols used at UMC. I also developed new capabilities to better manage this important and delicate task and to improve my ability to identify the appropriate techniques to increase both the efficiency and the efficacy of radiotherapy cancer treatments. This mobility grant provided an important opportunity to exchange knowledge and methods of treatment and enabled me to develop practical skills with other RTTs. It was really a fruitful experience, I want to thank ESTRO for the opportunity and last but not least the UMC Radiotherapy Department for the support and hospitality that I received, which I am forever grateful. SP-0333 Overview of the molecular interactions between radiotherapy and the immune system and immune checkpoint inhibitors A. Melcher 1 1 The Institute of Cancer Research, Division of Radiotherapy and Imaging, London, United Kingdom Abstract text Radiotherapy has the potential to induce immunogenic tumour cell death, which can activate an anti-cancer immune response. Therefore, in the context of the current expansion of clinical indications for immuno- oncology (IO) drugs, radiotherapy is an ideal treatment modality to test as part of combination strategies to enhance immunotherapy, which in general has a limited response rate. However, our understanding of the factors that determine whether radiotherapy is immune stimulatory or immune suppressive, including dose, fractionation and scheduling, is very limited. This talk will first outline, in general terms, our current knowledge of interactions between cancers and the immune system, highlighting some of the key molecules and pathways which have been identified as effective targets for immune therapy to date. It will then address how radiotherapy can impact on this cancer/immune interface, including i) the effects of radiotherapy on non- malignant cell components of the tumour microenvironment and ii) how a radiotherapy-induced DNA damage response can support anti-tumour immune priming. Finally, we will cover how radiotherapy might be most effectively and rationally combined with immune checkpoint inhibitors (ICI), as these are currently the most effective class of IO agents. Although there are multiple current trials combining radiotherapy with ICI, these protocols are not generally embedded within the pre-clinical data which might inform optimally effective combinations. Moreover, it is essential to maximise translational research within radiotherapy/IO combination studies, to enhance our understanding of the Symposium: Immuno-radiotherapy: the critical influence of radiation dose, scheduling and dose per fraction

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is very consistent between different algorithms while MBDCA and MC showed worse agreement. Tissue segmentation issues will most likely be part of the clinical routine soon and differences should be clarified so treatments from different centers, possibly using different commercial systems, can be compared. SP-0332 Science slam: Report back from ESTRO mobility grants RTT E. Strata 1 , M. Sarra Fiore 1 , B.A. Jereczek-Fossa 1 1 IEO - European Institute of Oncology, Radiotherapy, Milano, Italy Abstract text Report back from ESTRO Mobility Grants RTT E. Strata (1), M. Sarra Fiore (1), B.A. Jereczek-Fossa (1;2) 1 Division of Radiation Oncology, European Institute of ONCOLOGY, Milan Italy 2 Department of Oncology and Hemato-oncology, University of Milan, Italy There cannot be any limitations or borders in order to keep up with new technological innovations in the medical field and give our patients the best care they deserve. We can improve ourselves and our skills by observing and studying new realities and nonetheless, sharing ideas and knowledge with other professionals. Cultural exchange and interdisciplinary science are the basis to fulfill these purposes. Thanks to the Estro Mobility Grant I had the great opportunity of spending two weeks in Utrecht Medicine Center (UMC) Radiotherapy Department. The aim of my visit was to improve my knowledge of various imaging techniques and protocols currently used at the UMC Radiotherapy Department for IGRT treatments. Moreover, my ultimate goal was to be able to improve the approach to IGRT modality and protocol at the European Institute of Oncology in Milan, Italy. During my visit, I was significantly involved in observing various cancer treatments focusing on IGRT treatments and protocols that use on-line CBCT image guidance. I have improved my understanding of the way in which radiation