ESTRO 2020 Abstract Book

S529 ESTRO 2020

PO-0992 Pericardial effusion after radiotherapy for Non-Small Cell Lung Cancer C. Linthorst 1 , R. Wijsman 2 , M. Fernandes 1 , S. Barbara 3 , J. Teuwen 4 , D. Bosboom 4 , R. Monshouwer 1 , J. Bussink 1 1 Radboud University Medical Center, Radiation Oncology, Nijmegen, The Netherlands ; 2 UMCG, Radiation Oncology, Groningen, The Netherlands ; 3 Netherlands Cancer Institute, Department of Radiation Oncology, Amsterdam, The Netherlands ; 4 Radboud University Medical Center, Radiology and Nuclear Medicine, Nijmegen, The Netherlands Purpose or Objective In locoregionally advanced Non-Small Cell Lung Cancer (LA- NSCLC) patients treated with radiation therapy, higher mean cardiac dose is associated with more grade 3 cardiotoxicity. Higher cardiac dose is also associated with a higher incidence of pericardial effusion. According to literature, up to 45% of the patients have pericardial effusion in the first two years after radiation therapy for LA- NSCLC. Importantly, higher cardiac dose, and even limited pericardial effusion is related to a detrimental outcome. At the moment, it remains unclear which patients are at risk for developing pericardial effusion and cardiac events. The aim of this study was to investigate associations between cardiac dose, clinical and radiological pericardial effusion and clinical outcomes in patients treated with (chemo-) radiotherapy for NSCLC. Material and Methods Patients with stage III NSCLC treated in our institution between 2008-2017 with IMRT of VMAT radiation therapy (60-66Gy in 2Gy fractions) with follow-up (FU) CT scans were analyzed. Pericardial effusion was assessed on the planning and follow-up CT scans, using the radiological report and Common Terminology Criteria for Adverse Events (CTCAE) v4.0 criteria. Additionally, pericardial thickness was quantitatively assessed on pre- and post- treatment CT scans by measuring the pericardial thickness at 3 predefined sites along the left and right ventricle and left atrium. Dosimetric data of heart and cardiac substructures, assessing atria and ventricles separately and combined, were obtained from the dose volume histograms. Patient records were reviewed for the clinical outcomes, including cardiac events, overall survival and disease free survival. Spearman’s correlations were calculated to analyse associations between cardiac dose, pericardial effusion and cardiac events. Results A total of 105 patients were analyzed, follow-up time ranged from 1 to 10 years. Of these patients 29 (27.6%) had a cardiac history, most frequently myocardial infarction, followed by angina pectoris. One patient had previously diagnosed pericarditis. In FU, 13 Patients (12.4%) had pericardial effusion according to the radiological reports. Cardiac events were present in 17 (16.2%) of patients in FU. Further results will be presented. Figure one shows the CT images prior to chemoradiotherapy (66Gy at 2Gy/fraction combined with 2 courses of PE) and one year after treatment. The images clearly shows substatiol developmet of pericardiall effusion still present at one year after treatment. Conclusion In this retrospective study we detected a substantial proportion of patients with pericardial effusion after radiotherapy for stage III NSCLC. Associations between cardiac dose, clinical and radiological pericardial effusion, along with the full dosimetric analysis, will be presented. PO-0993 Multicenter study of stereotactic body radiotherapy in non-small cell lung cancer (KROG 17- 09) S. Park 1 , J.H. Kim 1 , Y.C. Ahn 2 , J.M. Noh 2 , W.C. Kim 3 , M.K. Kang 4 , J.H. Cho 5 , J.S. Kim 6 , M. Kong 7 , J.W. Yea 8 , Y.S. Kim 9 , K.H. Choi 9 , S.G. Yeo 10

1 Keimyung University Dongsan Medical Center, Radiation oncology, Daegu, Korea Republic of ; 2 Samsung Medical Center, Radiation Oncology, Seoul, Korea Republic of ; 3 Inha University Hospital, Radiation Oncology, Incheon, Korea Republic of ; 4 School of Medicine- Kyungpook National University, Radiation Oncology, Daegu, Korea Republic of ; 5 Yonsei University College of Medicine, Radiation Oncology, Seoul, Korea Republic of ; 6 Seoul National University Bundang Hospital, Radiation Oncology, Seongnam, Korea Republic of ; 7 Kyung Hee University Medical Center, Radiation Oncology, Seoul, Korea Republic of ; 8 Yeungnam University College of Medicine, Radiation Oncology, Daegu, Korea Republic of ; 9 College of Medicine- The Catholic University, Radiation Oncology, Seoul, Korea Republic of ; 10 Soonchunhyang University College of Medicine, Radiation Oncology, Cheonan, Korea Republic of Purpose or Objective Korean radiation oncology group designed a multicenter retrospective study to evaluate the clinical outcomes of stereotactic body radiotherapy (SBRT) in patients with early stage non-small cell lung cancer (KROG 17-09). In this report, we will present an interim analysis of the study. Material and Methods Newly diagnosed T1-2N0M0 non-small cell lung cancer patients treated with SBRT from 2005 to 2014 were included and the patients who received additional surgery or systemic therapy were excluded. A total of 234 patients from 10 institutions were registered. The patients’ and tumor characteristics, and treatment details were retrospectively reviewed. Various SBRT schedules were used in each institution. Median radiation dose and fraction size were 60 Gy (range, 40-70) and 12 Gy (range, 5-20), respectively. The representative schedules are as follows; 60 Gy/4 fractions, 60 Gy/5 fractions, 48 Gy/4 fractions and 54 Gy/3 fractions in 67 (28.6%), 40 (17.1%), 31 (13.2%) and 16 (6.8%) patients, respectively. Results The median age was 76.5 years (range, 44-91) and the majority was male (76.9%). While 152 patients (65.0%) had an ECOG performance status of 0 to 1, 82 (35.0%) had an ECOG of 2 to 3, and 120 (51.3%) had underlying lung disease. Majority of patients (91.0%) underwent pathologic confirmation of primary tumor. The median tumor size was 25 mm (range, 7-58). According to AJCC 7 th staging system, 154 patients (65.8%) were confirmed as T1, and 80 (34.2.%) were as T2. Seventeen patients (7.3%) were confirmed as N0 using pathologic mediastinal lymph node evaluation, while the others (92.7%) were confirmed as N0 radiologically. After the median follow-up of 28.5 months, 84 patients (35.9%) had disease failure; local (involved) failure without regional or distant failure in 20 (8.5%), locoregional failure in 12 (5.1%) and distant failure in 52 (22.2%). The 3-year primary tumor control, local control, regional control and distant control was 85.5%, 79.9%, 83.3% and 75.3%, respectively. The 3-year overall survival, cancer-specific survival and disease-free survival was 54.1%, 66.9% and 43.2%, respectively. Grade ≥3 treatment- related toxicities were reported in 16 patients (6.9%). Conclusion n this analysis, we were able to report the characteristics and clinical outcomes of SBRT in patients with early stage non-small cell lung cancer. In the subsequent analysis, we will detail the patient- and treatment-related factors associated with the clinical outcomes. PO-0994 Prognostic factors in elderly patients with lung carcinoma (NSCLC) treated with curative intent J. Cacicedo 1 , J.L. Lopez-Guerra 2 , B.D. Delgado 2 , L. Martinez-Indart 3 , O. Del Hoyo 1 , R. Ortiz de Zarate 4 , D. Büchser 1 , A. Gomez-Iturriaga 1 , F. Andere 1 , I. San Miguel 1 , F. Suarez 1 , A. Gonzalez 1 , E. Mayrata 1 , A. Barcena 5 , F. Casquero 1 1 Cruces University Hospital/Biocruces Health Research