Incidental findings during lung cancer screening by low-dose computed tomography

In Moscow in 2017, the project named Moscow Screening for Lung Cancer was started using low-dose computed tomography (LDCT) for selective screening for lung malignant tumors in the out-patient facilities and polyclinics.

The main goal of the project: to improve early detection of lung cancer and reduce mortality caused by this disease in the long term.

The objective of the study: to assess the importance of incidental findings during selective screening for lung cancer by LDCT in Moscow.

Subjects and Methods. The retrospective study included 254 randomly selected LDCT, which were performed as a part of the screening program. During the repeated examination of images and protocols, all abnormalities were taken into account (but for foci in the lungs evaluated as per LungRADS-2014).

Results. When analyzing the dissemination and character of incidental findings, detected by LDCT screening, it was found out that such findings had high clinical and/or predictive value in the majority of cases. The following disorders were detected the most often (% of those with incidental finding): coronary artery calcium - 49.3%; thickening of bronchial walls - 34.9%; bronchiectasis - 34.9%; emphysema - 21.6%.

During primary interpretation of LDCT results, less attention was paid to description of abnormalities but for foci evaluated as per Lung RADS-2014. Further research and organization are needed to provide detection and reasonable routing for those with incidental findings.

Conclusions. Incidental findings occur in 87.1% of cases during selective screening for lung cancer by LDCT. The majority of incidental findings are located in the cardio-vascular (75.4%) and respiratory (68.3%) systems, and they possess clinical and predictive value.

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