Radiation and circulatory disease

Abstract

Exposure to therapeutic doses of ionizing radiation is associated with damage to the heart and coronary arteries. However, only recently have studies with high-quality individual dosimetry data allowed this risk to be quantified while also adjusting for concomitant chemotherapy, and medical and lifestyle risk factors. At lower levels of exposure the evidence is less clear. In this article we review radiation-associated risks of circulatory disease in groups treated with radiotherapy for malignant and non-malignant disease, and in occupationally- or environmentally-exposed groups receiving rather lower levels of radiation dose, also for medical diagnostic purposes. Results of a meta-analysis suggest that excess relative risks per unit dose for various types of heart disease do not differ significantly (p>0.2) between studies. In particular, there are no marked discrepancies between risks derived from the high-dose therapeutic and medical diagnostic studies and from the moderate/low dose occupational and environmental studies. However, risk for stroke and other types of circulatory disease are significantly more variable (p<0.0001), possibly resulting from confounding and effect-modification by well known (but unobserved) risk factors. Adjustment for any of mean dose, dose fractionation or age at exposure results in the residual heterogeneity for cerebrovascular disease becoming non-significant. The review provides strong evidence in support of a causal association between both low and high dose radiation exposure and most types of circulatory disease.

Mortality from Circulatory Diseases and other Non-Cancer Outcomes among Nuclear Workers in France, the United Kingdom and the United States (INWORKS)

“…At doses below this level, evidence was not considered sufficient to conclude a causative relationship between circulatory disease and ionizing radiation. In this study, significant risks for circulatory disease were detected down to slightly lower dose levels (0.3 Gy), which tallies with findings from a recent review of circulatory disease (52) that concluded there may be a radiation-induced effect even at low doses.…”

Special issue: Tissue reactions to ionizing radiation exposure

“…Grubber and Dörr consider the radiobiology of the oral mucosa, which is important in light of the adverse reactions to radiotherapy [7]. With respect to effects on the heart and cardiovascular effects, Little reviews the epidemiology [8] and Boerma et al the biology [9]. Hendry and Otsuka provide an overview of intestinal biology [10], and Marjault and Allemand review the effects of radiation on spermatogenesis [11].…”

Low dose radiation therapy for COVID-19 pneumonia: is there any supportive evidence?

“…According to risk factors evaluated by the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR 2008) based on the Japanese atomic bomb survivor data, the acutely delivered lung doses of 0.3-1 Gy proposed by Kirkby and Mackenzie (2020) would nominally induce 0.6-4.4 excess lung cancers in a hundred persons exposed. There is also accumulating evidence of association between moderate and low dose ionizing radiation and most types of circulatory disease (Little et al 2012;Little 2016). Taken at face value a single 0.3-1 Gy lung dose (which the heart and aorta would also receive) would be associated with 0.8-7.6 extra deaths from circulatory disease in a hundred persons exposed (Little et al 2012).…”