PV QA 4 - Poster Viewing Q&A 4
TU_30_3611 - Association Between Radiation Heart Dosimetric Parameters, Myocardial Infarct and Overall Survival in Stage III Non-Small-Cell Lung Cancer Treated with Definitive Thoracic Radiation Therapy
Tuesday, October 23
2:45 PM - 4:15 PM
Location: Innovation Hub, Exhibit Hall 3
Association Between Radiation Heart Dosimetric Parameters, Myocardial Infarct and Overall Survival in Stage III Non-Small-Cell Lung Cancer Treated with Definitive Thoracic Radiation Therapy
C. C. Lee1,2, H. Zheng3, Y. Y. Soon1,2, L. L. Foo3, W. Y. Koh1,2, C. N. Leong1,2, B. Vellayappan1,2, J. Tey1,2, and I. W. Tham1,2; 1National University Cancer Institute, Singapore, Singapore, Singapore, 2National University Hospital, Singapore, Singapore, Singapore, 3National Registry of Diseases Office, Health Promotion Board, Singapore, Singapore
Purpose/Objective(s): This retrospective observational study aims to assess the association between various radiation heart dosimetric parameters (RHDPs), acute myocardial infarct (AMI) and overall survival (OS) in stage III non-small-cell lung cancer (NSCLC) treated with definitive thoracic radiotherapy with or without chemotherapy. Materials/Methods: We identified eligible patients treated at two institutions from 2007 to 2014. We linked their electronic medical records to the national AMI and death registries. We performed univariable and multivariable Cox regression analyses to assess the association between RHDPs, AMI and OS. Results: 120 patients were included. Median follow-up duration was 17.6 months. Median age was 65.5 years. 14% had pre-existing ischemic heart disease. 86% received chemotherapy. Median prescription dose was 60 Gy. Median heart dose (MHD) was 12.6 Gy. Five patients developed AMI at a median interval of 9.6 months from first day of radiotherapy. Univariable analysis showed that higher MHD (hazard ratio (HR), 1.03; 95% confidence interval (CI), 1.01-1.06; P= 0.008) and volume of heart receiving at least 5 Gy (V5) (HR, 1.01; 95% CI, 1.00-1.03; P= 0.042) were associated with increased hazards for AMI. Univariable analysis showed that higher MHD, V5, V25, V30, V40, V50 and dose to 30% of heart volume were significantly associated with increased hazards for death. Multivariable analysis showed that there was no statistically significant association between various RHDPs and OS. Conclusion: The incidence of AMI is low among stage III NSCLC treated with definitive radiotherapy. Based on our findings, there is insufficient evidence to conclude that RHDPs are associated with AMI or OS.
Author Disclosure: C. Lee: None. H. Zheng: None. Y. Soon: None. B. Vellayappan: None. I.W. Tham: None.