Abstract:
Objective To assess the effect of intensity modulated radiotherapy (IMRT) on electrocardiogram (ECG) findings and myocardial enzyme spectrum and B-type natriuretic peptide (BNP) levels in patients with lung cancer.
Methods We retrospectively reviewed the data of patients treated with IMRT at Tianjin Medical University Cancer Institute and Hospital between June 2013 and June 2015. In total, 203 patients were included. All patients underwent ECG and tests to determine myocardial enzyme spectrum and BNP levels before and 1, 2, and 3 months after IMRT. Risk factors were also evaluated.
Results The data revealed that the incidence of an abnormal ECG finding was 52.1% and that it mostly occurred in the first month after IMRT. The main abnormality noted was ST-T changes. The occurrence rate of ST-T changes after IMRT was statistically significant (P < 0.001). The incidences of abnormal myocardial enzyme spectrum and BNP levels were 39.9% and 4.9%, respectively. During the first 2 months after IMRT, creatine kinase (CK), creatine kinase isoenzyme (CK-MB), and BNP levels significantly increased (P=0.034; P=0.045; P=0.012). Tumor classification, concurrent chemoradiation, and total radiation dose were independent risk factors for abnormal ECG findings, whereas total radiation dose was an independent risk factor for abnormal myocardial enzyme spectrum and BNP levels.
Conclusion IMRT can result in abnormal ECG findings and abnormal CK, CK-MB, and BNP levels in patients with lung cancer. These damages are closely associated with the total radiation dose.