NEW YORK (Reuters Health) — Although the lifetime risk of cancer associated with exposure to radiation from computerise tomographic (CT) coronary angiography is “non-negligible”, the risk varies widely depending on the age and gender of the patient and type of scan that is used, according to a report in the Journal of the American Medical Association.

In their study, Dr. Andrew J. Einstein, from Columbia University Medical Center in New York, and colleagues estimated the lifetime of risk of cancer that could be attributed to exposure to CT coronary angiography radiation.

CT coronary angiography is conducted to assess patients with heart disease or suspected heart disease. It involves multiple X-ray scans of the vessels in the heart muscle after a contrast dye is injected to enhance the image.

Einstein’s group found that radiation doses to the lungs and the breast, in women, ranged from 42 to 91 mSv and 50 to 80 mSv, respectively.

Overall, the lifetime risk of cancer, based on age and gender, ranged from one in 143 for a 20-year-old woman to just one in 3,261 for an 80-year-old man. However, the corresponding risks fell to one in 219 and one in 5,017 with the use of simulated ECG controlled tube current modulation, a technique to reduce the amount of radiation.

The scans that combined cardiac and aortic imaging carried the highest risk of cancer. For instance, a 20-year-old woman undergoing these scans had a lifetime cancer risk of 1 in 114.

These estimates, derived from simulation models, suggest that CT coronary angiography is associated with a noteworthy increase in the lifetime risk of cancer, the authors conclude. Carefully selecting patients for CT and optimising the treatment plans of patients referred for testing can help minimise these risks.