Quantitative evaluation of radiation-induced heart disease in patients with lung cancer: a three-dimensional speckle tracking imaging study.

BACKGROUND

Adverse cardiovascular events due to radiation-induced heart disease (RIHD) have become the leading cause of death in cancer survivors, and early screening for RIHD has become an important clinical issue. Our objective was to determine the utility of three-dimensional speckle tracking echocardiography (3D-STE) for detecting RIHD.

METHODS

According to inclusion and exclusion criteria, patients with lung cancer who received radiotherapy in our hospital for the first time were recruited as subjects. All subjects underwent the conventional echocardiography and 3D-STE examination at six time points (1 day before radiotherapy, 2.5-3 and 5-6 weeks after beginning radiotherapy, and 3-, 6- and 12-month after ending radiotherapy). Routine electrocardiogram, serum cardiac troponin I (cTnI) and clinical data were detected simultaneously.

RESULTS

A total of 105 patients with lung cancer were included in the study. Conventional echocardiography found a small amount of pericardial effusion occurred in 8 subjects at 5-6 weeks after beginning radiotherapy. 3D-STE showed that, compared with before radiotherapy, the absolute values of global longitudinal strain (GLS) and global strain (GS) were significantly decreased at 5-6 weeks after beginning radiotherapy (P<0.001, P=0.002), and the absolute values of GLS, global radial strain, global circumferential strain, GS were gradually decreased further at 3-, 6- and 12-month after ending radiotherapy (P<0.001). Electrocardiograph showed that 32 subjects had electrocardiograph abnormalities during radiotherapy and 3 had electrocardiograph abnormalities at 3-month after ending radiotherapy, and most returned to normal within 6 months after ending radiotherapy.

CONCLUSIONS

Patients with lung cancer undergoing radiation therapy have shown a decrease in the function of the left ventricle of the heart while receiving treatment. Combining the assessment of cTnI with GLS can enhance the early detection of radiation-induced heart damage.