Dynamic Integrated Backscatter Detects Radiotherapy-induced Cardiac Changes Better than Strain Analysis - A Prospective Three-year Study

Abstract

Background/aim: Radiotherapy (RT) related myocardial changes were analyzed by deformation imaging echocardiography in this study.

Patients and methods: Ninety-nine breast cancer patients were studied at baseline, after chemotherapy, after RT, and three years after RT (3Y). Eighty patients received RT only, and twenty patients had right-sided breast cancer. Echocardiography included cyclic variation of the integrated backscatter in the septum (sCV) and posterior wall (pCV), global longitudinal strain (GLS), and left ventricular ejection fraction (LVEF).

Results: In patients with left-sided breast cancer, sCV declined from 11.3±3.3 dB at baseline to 10.3±2.9 dB after RT (p=0.001). No changes were observed after chemotherapy (p=0.211) or in patients with right-sided breast cancer after RT (p=0.977). No other parameters declined after RT. The decline in sCV was independently associated with the left anterior descending coronary artery radiation dose (β=-0.290, p=0.020).

Conclusion: In contrast to other parameters, sCV correlated with heart radiation dose.

Keywords: Radiotherapy; breast cancer; cyclic variation of the integrated backscatter; global longitudinal strain; myocardial imaging; speckle tracking echocardiography.