Performance of Lung-RADS in the National Lung Screening Trial

Abstract

Background Lung cancer screening with low-dose computed tomography (LDCT) has been recommended, based primarily on the results of the NLST (National Lung Screening Trial). The American College of Radiology recently released Lung-RADS, a classification system for LDCT lung cancer screening. Objective To retrospectively apply the Lung-RADS criteria to the NLST. Design Secondary analysis of a group from a randomized trial. Setting 33 U.S. screening centers. Patients Participants were randomly assigned to the LDCT group of the NLST, were aged 55 to 74 years, had at least a 30–pack-year history of smoking, and were current smokers or had quit within the past 15 years. Intervention 3 annual LDCT lung cancer screenings. Measurements Lung-RADS classifications for LDCT screenings. Lung-RADS categories 1 to 2 constitute negative screening results, and categories 3 to 4 constitute positive results. Results Of 26 722 LDCT group participants, 26 455 received a baseline screening; 48 671 screenings were done after baseline. At baseline, the false-positive result rate (1 minus the specificity rate) for Lung-RADS was 12.8% (95% CI, 12.4% to 13.2%) versus 26.6% (CI, 26.1% to 27.1%) for the NLST; after baseline, the false-positive result rate was 5.3% (CI, 5.1% to 5.5%) for Lung-RADS versus 21.8% (CI, 21.4% to 22.2%) for the NLST. Baseline sensitivity was 84.9% (CI, 80.8% to 89.0%) for Lung-RADS versus 93.5% (CI, 90.7% to 96.3%) for the NLST, and sensitivity after baseline was 78.6% (CI, 74.6% to 82.6%) for Lung-RADS versus 93.8% (CI, 91.4% to 96.1%) for the NLST. Limitation Lung-RADS criteria were applied retrospectively. Conclusion Lung-RADS may substantially reduce the false-positive result rate; however, sensitivity is also decreased. The effect of using Lung-RADS criteria in clinical practice must be carefully studied. Primary Funding Source National Institutes of Health.

An Official American Thoracic Society/American College of Chest Physicians Policy Statement: Implementation of Low-Dose Computed Tomography Lung Cancer Screening Programs in Clinical Practice

“…Lung-RADS categorizes LDCT findings based on likelihood of cancer and links each category with specific recommendations. Although reducing false positives, Lung-RADS may decrease sensitivity compared with NLST criteria, and its effects on clinical endpoints such as lung cancer mortality are unknown (51,52). Some programs have established similar structured reporting systems based on other nodule evaluation algorithms (21).…”

Screening for early stage lung cancer and its correlation with lung nodule detection

“…The criteria are different from the NLST protocol, mainly with the increase of threshold for positive results (from 4 to 6 mm diameter) and the use of growth for pre-existing nodules. When the criteria were applied to the NLST, the false-positive result rate was substantially reduced, whereas it also resulted in decreased sensitivity (90). Currently, it remains unknown how to balance the sensitivity of lung cancer detection and the false-positive rate (91).…”

Automatic Lung-RADS™ classification with a natural language processing system

“…Lung-RADS™ (LR) (8) has been shown to increase the positive predictive value of CTLS by a factor of 2.5, without significantly increasing false-negatives compared to the NLST (9,10). Implementing a CTLS reporting system using LR therefore promises to optimize patient outcome while effectively reducing economic burden secondary to unnecessary care escalation.…”