A Prospective Study on the Role of Strain Echocardiography in Detecting Early Radiation-induced Cardiotoxicity in...

Radiotherapy for breast cancer has a clear benefit for long-term survival and local control rate. However, it can negatively impact a patient's quality of life by affecting healthy surrounding normal tissues, including the heart and lungs. This study aimed to clarify the contribution of echocardiography with Global Longitudinal Strain (GLS) to early radiation-induced cardiotoxicity detection.

A prospective study was conducted on 25 early-stage left-sided breast cancer patients. All underwent 2D strain echocardiography before and one year after RT. Normality was assessed using the Shapiro-Wilk test and box plots. The Wilcoxon signed-rank test was conducted to compare GLS values. A statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 25.

Mean Global Longitudinal Strain value before and one year after radiotherapy was -20.2% and -21.2%, respectively. In half of these cases, the values ranged from -19.65% to -22.70% before radiotherapy and between -18.8% and -22.25% after radiotherapy. The non-parametric Wilcoxon test indicated no statistically significant difference before and after radiotherapy (Ζ = 0.902, p = 0.367).

Although no statistically significant reduction in GLS was observed one year post-radiotherapy, a decrease was noted in patients receiving higher cardiac doses, suggesting potential early subclinical myocardial changes. Strain echocardiography shows promise as a sensitive tool for the early detection of radiation-induced cardiotoxicity, warranting further research with larger cohorts and extended follow-up.

While this small cohort study did not show significant GLS changes post-RT, it highlights the need for larger studies with longer follow-ups to confirm the role of strain imaging in identifying early cardiotoxicity in breast cancer patients.