Abstract

Epidemiological and clinical evidence confirm that hearts are sensitive to ionizing radiation (IR). They are even more radiosensitive than formerly believed. Mechanistic studies show that the radiosensitivity is not due to the heart muscles but mainly to the cardiovascular system (CV). In fact, endothelial cells of the CV appear to be particularly affected by doses much lower than those used in radiation therapy. Also, low dose rate IR has been shown to induce premature senescence in endothelial cells. Thus, even relatively low « out-of-site » radiation doses in the treatment of breast tumours by radiation therapy may affect regular heart functions and cause heart disease. The present mini-review recalls recent findings suggesting that radiation protection of the heart even to reatively low radiation doses remains an important issue.

Keywords: Cardiovascular disease; Ionizing radiation; Low dose; Low dose rate; Radiation therapy; Epidemicology; Nuclear workers; Patients

Abbreviations: IR: Ionizing Radiation; RT: Radiation Therapy; LNT: Linear no-Threshold; ICRP: International Commission on Radiation Protection