Ask Dr KK: Can CT cause cancer?

Use of CT may account for 1.5 to 2 percent of all future cancers in the United States.

The 2006 Biological Effects of Ionizing Radiation VII lifetime attributable cancer risk model predicts that 1 in 1000 persons exposed to 10 mSv (single diagnostic CT scan of the neck, chest, abdomen, or pelvis) will develop cancer due to that single exposure.

The lifetime attributable cancer mortality risk attributable to a single radiation exposure in a one year-old child is 1 in 550 following an abdominal CT and 1 in 1500 following a brain CT.

It has been estimated that 29,000 future cancers could be attributed to CT scans performed in the US in 2007 alone.

1 in 500 women and 1 in 660 men will develop cancer from their abdominal CT scan if the procedure is performed at the age of 20.

A 45 year-old adult undergoing one single full-body CT procedure would accrue an additional lifetime attributable cancer mortality risk of 0.08 percent from a single scan.

The lifetime attributable cancer mortality risk is 1.9 percent lifetime for thirty years of annual scans.

About the author: Dr K K Aggarwal is Padmashri and Dr B C Roy National Awardee, President Heart Care Foundation of India, Dean Board of Medical Education Moolchand Medcity, Sr. Physician & Cardiologist, Visiting professor Clinical Research DIPSAR, Past President Delhi Medical Association, Past Academic and Research Wing Head IMA, Chairman Ethics Committee Delhi Medical Council.