Volumetric computed tomography screening for lung cancer: three rounds of the NELSON trial

N. Horeweg, C. van der Aalst, R. Vliegenthart, Y. Zhao, X. Xie, E. Scholten, W. Mali, E. Thunnissen, C. Weenink, H. Groen, J. Lammers, K. Nackaerts, J. van Rosmalen, M. Oudkerk and H. de Koning

European Respiratory Journal 2013;42(6):1659-1667.


Several medical associations recommended lung cancer screening by low-dose computed tomography scanning for high-risk groups. Counselling of the candidates on the potential harms and benefits and their lung cancer risk is a prerequisite for screening. In the NELSON trial, screenings are considered positive for (part) solid lung nodules with a volume >500 mm(3) and for (part) solid or nonsolid nodules with a volume-doubling time <400 days. For this study, the performance of the NELSON strategy in three screening rounds was evaluated and risk calculations were made for a follow-up period of 5.5 years. 458 (6\%) of the 7582 participants screened had a positive screen result and 200 (2.6\%) were diagnosed with lung cancer. The positive screenings had a predictive value of 40.6\% and only 1.2\% of all scan results were false-positive. In a period of 5.5 years, the risk of screen-detected lung cancer strongly depends on the result of the first scan: 1.0\% after a negative baseline result, 5.7\% after an indeterminate baseline and 48.3\% after a positive baseline. The screening strategy yielded few positive and false-positive scans with a reasonable positive predictive value. The 5.5-year lung cancer risk calculations aid clinicians in counselling candidates for lung cancer screening with low-dose computed tomography.