Dose to the Left Anterior Descending Artery Correlates With Cardiac Events After Irradiation for Breast Cancer

Although global heart dose has been associated with late cardiac toxic effects in patients who received radiation therapy for breast cancer, data detailing the clinical significance of cardiac substructure dosimetry are limited. We investigated whether dose to the left anterior descending artery (LAD) correlates with adverse cardiac events.We identified 375 consecutively treated female patients from 2012 to 2018 who received left-sided breast or chest wall irradiation (with or without regional nodal irradiation). Medical records were queried to identify cardiac events after radiation therapy. Mean and maximum LAD and heart doses (LAD DMedian follow-up time was 48 months. Thirty-six patients experienced a cardiac event, and 23 patients experienced a major cardiac event. On univariate and multivariable analyses, increased LAD DDose to the LAD correlated with adverse cardiac events in this cohort. Contouring and minimizing dose to the LAD should be considered for patients receiving radiation therapy for left-sided breast cancer.