Avoiding cardiac toxicity in patients undergoing curative intent radiotherapy for lung cancer

Abstract

Introduction: Lung cancer and ischaemic heart disease (IHD) are two of the five main causes of death in the United Kingdom and about a quarter of lung cancer patients have concomitant IHD. In the last three years evidence has emerged that increased heart dose is associated with poorer survival in patients treated with curative radiotherapy. Dose to the base of the heart appears to be particularly important, however cardiac dose volume constraints are not well defined. Methods: Deformable registration methodology will be applied retrospectively to 1000 lung cancer patients treated in Leeds with radical radiotherapy. We will analyse the planning CT data from the Leeds and Manchester cohorts to quantify coronary artery calcification using the Agatston score. We will obtain data on cardiac risk factors, hospital admissions and cause of death for these patients to conduct a multivariate survival analysis. The prospective trial aims to recruit 200 patients with a histological or clinical diagnosis of stage I-III lung cancer suitable for curative intent radiotherapy. Patients will have blood collected before, on completion of and four months after RT. Samples will be taken for: full blood count; lipids; cholesterol; high sensitivity troponin levels; C-reactive protein and brain natriuretic peptide. Fifty participants in Manchester will undergo cardiac CT, echocardiogram and 12-lead electrocardiogram at baseline and 4 months after radiotherapy. The biomarker and imaging data will be linked to heart dose and survival. Results: We will validate the correlation between heart dose and mortality in lung cancer patients treated with radiotherapy using another centre's dataset. We will obtain prospective data on cardiac blood biomarkers and imaging. We aim to use both retrospective and prospective data to derive cardiac dose constraints. Conclusion: This trial aims to improve the outcomes of lung cancer patients treated with radical radiotherapy by limiting heart dose and reducing cardiac events.