Lung Cancer Screening: Beyond Pulmonary Nodules

Low-dose CT lung cancer screening reduces lung cancer mortality in individuals at high risk and frequently reveals clinically relevant incidental findings. In the National Lung Screening Trial, approximately one-third of screening CT examinations demonstrated abnormalities other than lung cancer, raising challenges related to interpretation, reporting, and further management. The absence of consistent guidance and the variable clinical significance of these findings may hinder the broader adoption of lung cancer screening. Opportunistic screening leverages low-dose CT examinations performed for lung cancer detection to identify additional serious conditions at no extra cost, radiation exposure, or patient burden. The authors provide a practical framework for recognizing, reporting, and managing common opportunistic findings on lung cancer screening CT images, with an emphasis on evidence-based recommendations and current professional society guidance. Key thoracic findings include emphysema, interstitial lung abnormalities, interstitial lung disease, coronary artery calcification, thoracic aortic aneurysm, and pulmonary artery enlargement. Each of these findings, if unrecognized, is associated with substantial morbidity and mortality. Extrapulmonary findings such as low bone density and lesions found incidentally in the upper abdominal organs further expand the clinical value of lung cancer screening. The authors highlight standardized visual and quantitative assessment methods, recommended follow-up pathways, and the importance of structured reporting, including appropriate use of the Lung CT Screening Reporting and Data System "S" (other non-lung cancer findings) modifier. Emerging artificial intelligence tools are discussed as critical enablers for scalable opportunistic screening, offering automated detection, quantification, and longitudinal assessment of emphysema, coronary calcium levels, vascular dimensions, bone density, body composition, and selected abdominal pathologic conditions. By integrating opportunistic screening into routine lung cancer screening workflows, radiologists can extend the benefit of lung cancer screening with CT beyond cancer detection to facilitate comprehensive risk stratification and preventive care.