Evaluation of the Irradiated Volume of the Heart and Cardiac Substructures After Left Breast Radiotherapy

Abstract

Backround/Aim: Adjuvant radiotherapy in patients with cancer of the left breast may lead to impaired cardiac function. The aim of our prospective study is to evaluate (i) doses to the irradiated volume of the heart and its substructures and (ii) determine whether their correlation with changes in strain echo measurements contribute to the prediction of subclinical heart morbidity.

Patients and methods: Twenty-five patients were enrolled in our study. We retrospectively assessed the radiation doses to the whole heart, left anterior descending artery (LAD) and left ventricle (LV).

Results: The mean heart dose (MHD) was 152 cGy (SD=50.56 cGy) and the range was 74-279 cGy. The LAD was the most exposed structure, with a mean dose of 448.91 cGy (SD=490.53 cGy) and range of 120-2,057cGy. Finally, the mean LV dose was 149.12 cGy (SD=69.57) with a range of 63-317 cGy.

Conclusion: The early results of our study showed low radiation exposure of the whole heart and left ventricle, and higher exposure of the LAD. The data that will emerge from the evaluation of strain echo parameters should show whether these associations might be useful in clinical practice for the prediction of early subclinical cardiac changes.

Keywords: Breast cancer; LAD; LV; cardiotoxicity; echocardiography; mean heart dose; radiotherapy.