Coronary artery dosimetry in intact left breast irradiation.

Abstract

The left anterior descending coronary artery is anatomically located at the edge of the cardiac silhouette on traditional treatment films. Small changes in the perpendicular lung distance can significantly change the dose delivered to this vessel. A fundamental change in the shape of the dose-volume histogram occurs at a perpendicular lung distance of 2.3 cm, whereas the dose is very low when the perpendicular lung distance is less than 1.3 cm. These points may serve as clinically important values in the treatment planning for cancer of an intact breast.