John D. Mathews, MBBS, MD, PhD, DSc Hon, DMedSc Hon, Professor of epidemiology at the School of Population and Global Health, University of Melbourne, Carlton, Victoria, Australia Cancer risk in 680 000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians MedicalResearch.com: What are the main findings of the study? Prof Mathews: We found that for persons having at least one CT scan before the age of 20 years, and followed for an average period of 10 years, the average risk of cancer was increased by 24% compared with unexposed persons matched for age, sex and year of birth. The cancer risk increased by 16% for each CT scan that preceded the cancer by more than one year. The proportional increase in risk was greater for persons exposed at younger ages. (more…)