ESTRO 2020 Abstract book

S459 ESTRO 2020

Symposium: Multimodal approaches to oligometastatic disease: state-of-the-art in NSCLC

Joint Debate: ESTRO-ESGO: This house believes that lymph node dissection can be omitted in FIGO stage IB1/2(<4 cm)iN1(imaging) cervical cancer

SP-0737 Systemic treatment for OM-NSCLC: which, when, how much? W. Eberhard University of Duisburg-Essen, Essen, Germany

SP-0741 For the motion C. Chargari (France) Institut Gustave Roussy, Paris, France

Abstract not received

Abstract not received

SP-0738 Local ablative radiotherapy: targeting a selection or treating everything? F. McDonald The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom

SP-0742 Against the motion A. Fagotti (Italy) Division of Gynecologic Oncology, Catholic University of the Sacred Heart, Rome, Italy

Abstract not received

Abstract not received

SP-0743 For the motion rebuttal: Para-aortic lymph node sampling should always be performed in case of pelvic N+ disease E. Van der Steen-Banasik Radiotherapy Group, Arnhem, The Netherlands

SP-0739 The role of interventional radiology in oligometastatic disease L. Tselikas Gustave Roussy Université Pierre et Marie Curie, Paris, France

Abstract not received

Abstract not received

SP-0744 Against the motion rebuttal: PA LN sampling should always be performed in case of pelvic N+ disease S.K. Shrivastava 1 , S. Chopra Sastri 2 , D. Borade 3 1 tata Memorial Hospital, Radiation Oncology, Mumbai, India ; 2 tata Memorial Center, Radiation Oncology, Mumbai, India ; 3 apollo Hospitals, Radiation Oncology, Navi Mumbai, India Abstract text Pelvic and prophylactic para-aortic radiation has not been demonstrated to be superior to pelvic chemo-radiation in locally advanced cervical cancer within randomized trials. However, pelvic chemo-radiation alone in node positive patients is associated with para-aortic nodal failure in a significant proportion of patients. Currently there is no good way to select patients for prophylactic treatment of para-aortic region. Some of the patient selection strategies for elective para-aortic nodal irradiation are currently being tested in ongoing trials (EMBRACEII).To ensure that appropriate patients are selected for therapeutic intervention, in recent years, PET has been investigated for nodal lymph node staging. Though deemed to perform better than CECT and MRI the absolute sensitivity and specificity of PET-CT for detecting para- aortic LN metastasis is 50% (95% CI 7-93%) and 83% (52-98%) respectively. This suggests that PET may be missing para- aortic nodal disease in some patients predisposing proportion of patients to nodal relapse. There is some evidence showing that surgical staging may lead to modification of treatment portals in 20-40% of patients. Randomized trials are currently underway to test the role of surgical staging. In the proposed talk, speaker will present the available evidence of surgical staging of para- aortic region in locally advanced cervical cancer.

SP-0740 Immunotherapy and SBRT in NSCLC: friends or enemies E. Troost 1 1 TU Dresden- Med. Faculty Carl Gustav Carus, Radiotherapy and Radiation Oncology, Dresden, Germany following radio(chemo)therapy has entered the clinical arena, mainly applying conventional fractionation schedules. Following the results of randomized clinical trials, i.e. increased overall survival, this is true for locoregionally advanced stages of NSCLC. At present, clinical trials in early NSCLC patients, eligible for stereotactic radiotherapy (SABR), are being initiated, thus increasing the dose per fraction and reducing the overall treatment time. The aim of these is merely to decrease the incidence of regional and distant metastases as opposed to increase the local control rate, which is already high. In light of the oligometastatic state, which is increasingly been proposed in tumors such as NSCLC, the combination of SABR with any form of immunotherapy appears promising in increasing progression-free- and overall survival. This presentation will briefly summarize available clinical evidence for immunotherapy as well as different immunotherapeutic approaches. Moreover, available pre- clinical data will be presented. Lastly, an outlook on the remaining challenges and questions will be given. Abstract text In recent years, immunotherapy