Importance of consideration of radiation doses from cardiac imaging procedures and risks of cancer

Excerpt

In recent years, there has been more attention and publicity to the radiation exposure experienced by patients undergoing cardiac imaging procedures such as computed tomography coronary angiography (CTA) and SPECT and PET perfusion imaging. The risk of radiation-related cancer risk from CT scans performed in the United States has not been adequately appreciated. Recent publications have voiced concern regarding future cancer risks from the many CT scans performed on an annual basis in the United States.1-3 What is surprising and somewhat alarming is that radiation doses from diagnostic CT examinations are higher and more variable than generally quoted.3,4 The issue is not a trivial one since between 1992, the number of CT scans performed in the United States quadrupled. In 2007 alone, 72 million CT scans were performed.5 It was estimated that from this number, 29,000 excess cancers would result causing 15,000 deaths in the next 20 to 30 years. Another study published in the New England Journal of Medicine surveyed 952,420 adults between the ages of 18 and 64 over a 3-year period.2 Of these, 69% (655,613) underwent at least one imaging procedure associated with radiation exposure. CT and nuclear imaging accounted for just 21% of the total number of procedures but 75.4% of the total cumulative effective dose. In this study, a high radiation dose was defined as >20-50 mSv and a very high dose as >50 mSv. High and very high doses were incurred in 18.6 and 1.9 enrollees per 1000 per year, respectively. Cumulative effective doses of radiation increased with advancing age and were higher in women than in men. …