Duplex Imaging Assessment of the Internal Mammary Arteries in Women after Unilateral Mastectomy and Radiotherapy for Breast Cancer

Abstract

The effects of incidental radiation exposure on internal mammary arteries remain unclear. The present study was designed to test the hypothesis by comparing diameter and blood flow of the irradiated and nonirradiated internal mammary arteries, using Duplex ultrasound imaging. The study was designed as a single-center, transversal, comparative study. The main outcomes were diameter and volumetric blood flow of the internal mammary arteries. The Wilcoxon rank-sum test was used to assess the differences between the irradiated and nonirradiated internal mammary arteries with regard to the diameter and volumetric blood flow. The diameter (median [interquartile range]) of the irradiated internal mammary arteries (0.170mm [0.160, 0.180]) was smaller than that of the contralateral nonirradiated ones (0.180mm [0.170, 0.200], P<0.0001) and that of the internal mammary arteries in the control group (0.180mm [0.170, 0.190], P<0.0001). Similarly, blood flow (median [interquartile range]) of the irradiated internal mammary arteries (52.4ml/min [37.78, 65.57]) was smaller than that of the contralateral nonirradiated ones (62.7ml/min [46.87, 84.17], P<0.0001), as well as of the left (56.7ml/min [46.88, 72.58], P=0.02) and the right internal mammary arteries in the control group (61.0ml/min [47.47, 74.52], P=0 0.0009). The data indicate that the irradiated internal mammary arteries in patients with a history of total mastectomy followed by radiotherapy for breast cancer had significantly smaller diameter and blood flow compared to the nonirradiated internal mammary arteries.