Differences in coronary calcium scores obtained by chest computed tomography in lung cancer patients before and after mediastinal radiotherapy

Abstract

Cardiovascular disease (CVD) is a leading non-cancer cause of morbidity and mortality among survivors of lung cancer and other thoracic malignancies treated with radiotherapy. Thoracic radiotherapy can accelerate atherosclerosis, especially in patients with pre-existing cardiovascular risk factors. Coronary artery calcification (CAC) on CT is a validated predictor of future cardiovascular events. However, data on CAC progression after mediastinal radiotherapy in lung cancer patients are limited. To evaluate changes in CAC on non-gated chest CT before and after mediastinal radiotherapy in lung cancer patients, and to explore associations with cardiac radiation dose and ASCVD risk. We retrospectively analyzed 30 patients with histologically confirmed lung cancer treated with curative mediastinal radiotherapy (2019–2024) who had pre- and post-treatment chest CT scans. CAC was quantified using Agatston score, calcium volume, mass, and MESA score. Wilcoxon and Chi-square tests assessed changes; Spearman analysis evaluated correlations with radiation dose and ASCVD risk. ROC curves tested whether the number of radiotherapy sessions predicted CAC presence. Significance was set at p<0.05. Mean age was 67.3±11.7 years; 50% were female. Adenocarcinoma was most common (43.3%). Median radiotherapy sessions were 25 (range 5–46). Post-radiotherapy, CAC increased significantly in the left main (p=0.018), left anterior descending (p=0.004), and right coronary artery (p=0.010), as well as in total score, volume, mass, and MESA score (all p≤0.033). The number of affected arteries and severity also increased (p<0.001). No correlations were observed between total or mean cardiac radiation dose and CAC changes (p=0.205, 0.288). CAC change negatively correlated with ASCVD risk (rho=-0.687, p<0.001). ROC analysis did not identify a predictive threshold for radiotherapy sessions (AUC 0.51). Mediastinal radiotherapy in lung cancer patients is associated with significant increases in CAC, affecting more coronary arteries with greater severity. While radiation dose was not directly correlated, CAC assessment via routine chest CT provides a practical tool for cardiovascular risk stratification. Early detection of CAC may inform preventive interventions and cardioprotective strategies in this high-risk population.Difference in calcium score and CAC-DRS  Changes in CAC-DRS after radiation