Session Item

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.

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.

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.

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.