Acute Radiation Effects on Cardiac Function Detected By Strain Rate Imaging in Breast Cancer Patients

Purpose To investigate the occurrence of early radiation-induced changes in regional cardiac function using strain rate imaging (SRI) by tissue Doppler echocardiography. Methods and Materials We included 20 left-sided and 10 right-sided breast cancer patients receiving radiotherapy (RT) to the breast or chest wall. Standard echocardiography and SRI were performed before RT (baseline), immediately after RT (post-RT), and at 2 months follow-up (FUP) after RT. Regional strain (S) and strain rate (SR) values were obtained from all 18 left ventricular (LV) segments. Data were compared to the regional radiation dose. Results A reduction in S was observed post-RT and at FUP in left-sided patients (S post-RT : −17.6 ± 1.5%, and S FUP : −17.4 ± 2.3%, vs. S baseline : −19.5 ± 2.1%, p post-RT : −15.3 ± 2.5%, and S FUP : −14.3 ± 3.7%, vs. S baseline : −19.3 ± 3.0%, p post-RT : −1.06 ± 0.15 s −1 , and SR FUP : −1.16 ± 0.28 s −1 , vs. SR baseline : −1.29 ± 0.27s −1 , p = 0.01), but not in mid- or basal segments. Furthermore, we observed that segments exposed to more than 3 Gy showed a significant decrease in S after RT (S post-RT : −16.1 ± 1.6%, and S FUP : −15.8 ± 3.4%, vs. S baseline : −18.9 ± 2.6%, p Conclusions SRI shows a dose-related regional decrease in myocardial function after RT. It might be a useful tool in the evaluation of modern RT techniques, with respect to cardiac toxicity.