Related Experiment Video
Updated: Mar 29, 2026
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Radiotherapy Induces Development of Fragmented QRS in Patients with Breast Cancer
Adem Adar1, Emine Canyılmaz2, Abdulkadir Kiris3
1Cardiology Clinic, Karabuk University Hospital, Karabuk, Turkey.
Background:
Myocardial fibrosis is a well-known side effect of radiotherapy. Fragmented QRS (fQRS) has been shown to be a marker of myocardial fibrosis. We postulated that radiotherapy induces development of fQRS in breast cancer patients.
Patients And Methods:
Breast cancer patients receiving locoregional radiotherapy were enrolled. Patients who had fQRS on electrocardiography (ECG) before radiotherapy were excluded. All patients were revaluated for the development of fQRS at 1-year follow-up. An age-matched healthy group served as controls.
Results:
A total of 52 breast cancer patients receiving locoregional radiotherapy were included (median age 49 years, interquartile range (IQR) 13). Of these, 19 (37%) had developed fQRS at 1-year follow-up. Compared with the control group, prevalence of fQRS was significantly higher in the irradiated group (37 vs. 12%; p < 0.002). Median total cardiac radiation dose was significantly higher in patients who had developed fQRS (5 Gy, IQR 5.2 vs. 1.7 Gy, IQR 4.4; p = 0.003). Cardiac radiation dose, entered either as a continuous variable (odds ratio (OR) 1.35, 95% confidence interval (CI) 104-1.74) or as a dichotomized variable (≥ 2.2 Gy, OR 6.48, 95% CI 1.47-28.61), was independently associated with the development of fQRS at 1-year follow-up.
Conclusion:
Radiotherapy for breast cancer induces development of fQRS on ECG. Cardiac radiation dose is independently associated with the development of fQRS.
