Radiation exposure from CT scans in childhood could triple the risk of leukaemia and brain cancer

Children and young adults scanned multiple times by computed tomography (CT) have a small increased risk of leukaemia and brain tumours in the decade following their first scan.
The findings from a study of more than 175,000 children and young adults was led by researchers at Newcastle University and at the National Cancer Institute, part of the National Institutes of Health, USA.
The researchers emphasise that when a child suffers a major head injury or develops a life-threatening illness, the benefits of clinically appropriate CT scans should outweigh future cancer risks.
Lead author Dr Mark Pearce, Reader in Lifecourse Epidemiology at Newcastle University said: ‘CT scans are accurate and fast so they should be used when their immediate benefits outweigh the long-term risks. However, now we have shown that CT scans increase the risk of cancer, we must ensure that when they are used they are fully justified from a clinical perspective.’
The study represents the culmination of almost two decades of research in this area at Newcastle University, and is jointly funded by the UK Department of Health and NCI/NIH.
CT imaging is a vital and commonly used diagnostic technique and it is used more frequently in countries such as the USA and Japan. However, CT scans deliver a dose of ionising radiation to the body part being scanned and to nearby tissues. Even at relatively low doses, ionising radiation can break the chemical bonds in DNA, causing damage to genes that may increase a person