The impact of radiologists’ expertise on screen result decisions in CT lung cancer screening

Methods In the Dutch-Belgian randomized lung cancer screening trial (NELSON), the baseline CT screen result was based on the lung nodule with largest volume. According to the protocol, nodule volume<50mm3, 50-500mm3 and >500mm3 led to a negative, indeterminate and positive screen result, respectively. The protocol, however, allowed radiologists to manually adjust screen result in case of high suspicion of benign or malignant nodule nature. In this study, all participants whose baseline CT result was based on a solid nodule were included. Adjustments by radiologists at baseline were evaluated. Histology was the reference for diagnosis, or, to confirm benignity, stability on subsequent CT scans.