RESUMEN
INTRODUCTION: The primary objective of radiation therapy (RT) is to deliver lethal radiation doses to abnormal cancer cells so that healthy cells are exposed to minimal radiation. In the present study, changes in electrocardiography (ECG) and echocardiography(ECHO) following adjuvant RT were investigated in patients with left-sided breast cancer. MATERIALS AND METHODS: 30 patients with left-sided breast cancer who had previously undergone breast-conserving surgery or mastectomy underwent RT after completing chemotherapy from February 2019 to January 2020. ECG and ECHO tests were performed before RT, immediately following RT, and three months after RT. Dose-volume parameters of the heart and its substructures as an organ at risk were analyzed. RESULTS: The mean heart dose (±SD) for all patients was 7.51 ± 2.42 Gy. T-wave inversion was observed 3 months after RT in 47% of patients. T-wave decline was associated with mean heart radiation dose (ß = 0.605, p-value = 0.005). The present study showed that the left ventricular volume receiving the 5 Gy (LV-V5) parameter was associated with a reduction in ST segment duration (p-value = 0.027) as well as with an increase in left ventricular systolic diameter (LVESD, mm) (P-value = 0.027). CONCLUSION: RT-induced ECG and ECHO changes are frequent in patients with left breast cancer. LVEF and Twave abnormalities were observed after RT in our patients. ECG and ECHO modalities can be used to monitor the cardiac function after RT in patients with left-sided breast cancer.
