CT of coronary arteries especially risky for women
Computed tomography (CT) of the coronary arteries is one alternative to traditional coronary angiography for patients with chest pain. It's less invasive, but it exposes patients to a substantial dose of ionizing radiation. There is no way of knowing the exact risks of cancer associated with each scan. But they could be substantial, particularly for young women. According to the latest estimates, coronary artery scans are associated with a lifetime risk of cancer of one in 143 for a 20 year old woman, although the risks go down quickly with age. The risks look much lower for men of any age, and by 80 years the estimated lifetime attributable risk from one scan falls to only one in 1338.
These figures are "best guesses," as there are no data linking real scans with real cancers, say researchers. Instead, they calculated the risks using an established model based on multiple other sources, including Japanese survivors of the atomic bomb. In their study, women were particularly vulnerable to cancers of the breast, and both sexes were prone to cancers of the lung. Risks were reduced by minimising the dose of radiation given with each scan and increased by extending the scan as far as the aortic arch.