Abstract Book

ESTRO 37 20-­‐24 April 2018 Barcelona, Spain

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ESTRO 37, Saturday 21 April

environment including the immune system. Especially in the era of immune checkpoint inhibition (ICI) as an effective cancer therapy the systemic immune- modulating effects of ionizing radiation (SIMEIR) are of great interest. Especially since RT is inducing immunogenic cancer cell death acting as an in situ cancer vaccine. However, only if the additional microenvironmental conditions are beneficiary, the immune system can be trained to attack the primary tumor and the metastases. The modulation of the peripheral immune system RT might picture the direction of the immune response, suppression or activation, respectively. This information should be available during the whole multimodal cancer therapy. Therefore we developed the detailed immunophenotyping of whole blood (DIoB) assay to get insights in particular on systemic changes of peripheral immune cell compositions and activation state. In several clinical trials the DIoB assay has already been used to analyze the dynamics of several immune cells (sub)types during the whole multimodal therapy of the patients. During the training course the development of the DIoB assay will be shortly presented and in particular results of the several trials will be discussed with possibilities and challenges of immunophenotyping for prediction and prognosis. An understanding of the immunologic dynamics during multimodal cancer treatment will be communicated. We conclude that knowledge on systemic immune modulations induced by ionizing radiation is important to optimize multimodal radioimmunotherapies for cancer aiming to achieve local and systemic tumor control and to define immune-related biomarkers/-matrices of radiation exposure for prognosis and prediction SP-0003 Optimal sequence in the treatment of breast cancer: RT first? C. Coles 1 1 Addenbrooke's Hospital - Oncology Centre, University of Cambridge, Cambridge, United Kingdom Abstract text Optimal sequence in the treatment of breast cancer: RT first? Dr Charlotte Coles Post-operative breast radiation therapy (RT) is of proven benefit for improving local control and survival and is indicated for the majority of patients with early breast cancer. However, there can be technical challenges with planning and delivering breast RT in the adjuvant setting. Recently, there has been renewed interest in changing the sequence of breast RT delivery and bring forward before surgery. Preoperative breast RT is not an entirely new concept, but historical research studies have not impacted on clinical practice, possibly due to perceived/actual toxicity. Advances in breast RT such as intensity modulated RT (IMRT), accelerated partial breast irradiation (APBI), simultaneous integrated boost and (SIB) and image guided radiation (IGRT) that could facilitate preoperative RT and minimise side effects. This presentation will: · 1. Summarise the results of older trials· 2. Discuss the potential benefit of preoperative breast RT in facilitating: Teaching Lecture: Optimal sequence in the treatment of breast cancer: RT first?

Teaching Lecture: Radiation-induced cardiac toxicity: what have we learnt?

SP-0001 Radiation-induced cardiac toxicity: what have we learnt? D. Cutter 1 1 Oxford University, Clinical Trial Service Unit, Oxford, United Kingdom Abstract text The success of modern multi-modality cancer therapy, combined with a general improvement in life expectancy, has resulted in an increasing number of people surviving more than 5 years from a cancer diagnosis. Whilst improvements in survival rates are obviously to be welcomed, it is increasingly recognized that many cancer survivors are at an elevated risk of morbidity and mortality from a variety of causes. Cardiac disease is one such consequence, resulting in a substantial proportion of the burden of excess illness and death observed. There is compelling evidence from a number of independent sources that ionizing radiation can give rise to an increased risk of cardiac morbidity and mortality following the successful treatment of various types of cancer. Whilst it is certain that radiation techniques from previous decades resulted in substantially elevated risks, it is less certain what risk modern treatment regimens pose. Current research is aimed at clarifying the dose- response relationships of radiation-induced cardiac disease (RICD) so that the risks of contemporary treatments can be predicted and so that the advanced radiotherapy techniques now available to Radiation Oncologists can be put to optimal use. This interdisciplinary teaching lecture will summarize what is known regarding the nature, epidemiology and mechanisms of radiation-induced cardiac disease, will give an overview of what we have learned more recently and, importantly, what we still need to know regarding RICD in order to properly take account of this important treatment toxicity when managing patients today. SP-0002 Measuring the systemic immune-modulating effects of radiation B. Frey 1 , U. Gaipl 1 1 University Clinic Erlangen, Department of Radiation Oncology, Erlangen, Germany Abstract text The description of the so called abscopal effect of radiotherapy (RT) is more than 60 years ago. However, to date the literature only reports about individual clinical cases with anti-tumor effects out-of the irradiated field. RT is a common treatment for cancer and about 60% of all cancer patients will receive it during their course of illness. RT primarily aims to locally control the tumor by stopping the proliferation of the tumor cells and ideally by killing them. The main biological effects of ionizing irradiation are the induction of DNA damage and stress responses. This was though for decades to be strongly locally restricted, but nowadays it has become obvious that ionizing radiation is additionally able to modulate the tumor micro-environment as well as the macro- Teaching Lecture: Measuring the systemic immune- modulated effect of radiation

- Breast reconstruction - Breast conservation

- Partial breast irradiation - Translational research· 3. Highlight current preoperative breast RT research