Radiation Exposure and Cancer Risk from Low-Dose CT Lung Cancer Screening

In the National Lung Screening Trial, low-dose computed tomography (CT) screening lowered lung cancer–related mortality in high-risk patients (NEJM JW Gen Med Aug 1 2011 and N Engl J Med 2011; 365:395). However, concerns have been raised that radiation exposure from CT screening actually might increase risk for cancer. In this study, researchers calculated cumulative radiation exposure from 10 years of annual low-dose CT screening in 5200 high-risk smokers who participated in an Italian lung cancer screening trial. Then, the researchers estimated how many cancers this exposure theoretically would cause, according to models extrapolated from various sources, including occupational exposures and cancer rates among atomic bomb survivors.

The es…