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3. MEDICAL AND HEALTH SCIENCES, Radiology, nuclear medicine and medical imaging
A causal association between radiation exposure and various types of non-malignant diseases, especially cardiovascular diseases, has been extensively reported [1,2]. The risks of radiation-induced heart disease (RIHD) were described in therapeutically exposed cohorts of patients with thoracic tumors in which a high incidence of long-term complications (i.e., pericarditis, cardiomyopathy, coronary artery disease, valvular heart disease, conduction abnormalities and myocardial fibrosis) increased the risk of heart-disease-related mortality . Patients who received post-mastectomy radiotherapy for left-sided breast cancer were at a 2–3-time higher risk of developing cardiovascular disease, due to the apex and anterior wall of the heart being exposed to doses of radiation between 1 and 5 Gy on average . Nevertheless, at a median follow-up of 8 years, the risk of RIHD was not associated with the laterality of the irradiated breast . An increased risk for cardiovascular diseases, especially stroke and heart attack, also resulted from epidemiological studies of A-bomb survivors  as well as occupationally exposed workers . At these moderate doses (0.5–5 Gy), the mechanisms of action seem to especially involve atherosclerosis or vascular injury. Many animal studies support such evidence, indicating increased oxidative stress and the promotion of inflammation as possible mechanisms by which radiation promotes atherogenesis . Cardiac fibrosis and hypertrophy were also observed after the irradiation of mice with 0.5 Gy of protons or 0.15 Gy of 56Fe ions, at late time points.
Leonardi, S., Merla, C. & Babini, G. (2022). MiRNA-Mediated Fibrosis in the Out-of-Target Heart following Partial-Body Irradiation. Cancers, vol. 14, pg. 3463. doi:10.3390/cancers14143463
SEPARATE project, Euratom Research and Training Program 2014–2018, in the framework of CONCERT EJP (grant agreement No. 662287).