When the American College of Radiology (ACR) published the Lung CT Screening Reporting and Data System (Lung-RADS) in 2014, one of its goals was producing a lower false-positive rate than the 23.3 percent reported by the National Cancer Institute’s National Lung Screening Trial (NLST). A team of researchers put Lung-RADS to the test, exploring its effectiveness in a “diverse and underserved urban county” and sharing the results in the Journal of the American College of Radiology.
The authors studied a cohort of more than 1,100 patients screened with low-dose CT (LDCT) from December 2012 to December 2016. All patients were referred by a physician, and eligibility was confirmed by a screening coordinator. The mean age was 64 years old, 51 percent were women, 63 percent were nonwhite and 71 percent were current smokers.
Overall, the Lung-RADS false-positive rate was 10.4 percent. Mortality was 40 percent in patients with lung cancer and 2.5 percent in patients without lung cancer.
“In this first prospective validation of more than 1,000 patients, lung cancer screening using Lung-RADS proved effective in reducing the false-positive rate compared with the NLST,” wrote lead author Mark Kaminetzky, MD, department of radiology at the Montefiore Medical Center and Albert Einstein College of Medicine in the Bronx, New York, and colleagues. “We found a 10.4 percent false-positive rate, substantially lower than the 23.3 percent rate in the NLST. This lower false-positive rate is attributable primarily to the higher nodule cutoff size of 6 mm in Lung-RADS compared with the NLST’s 4-mm cutoff.”
The authors also noted that they had a sensitivity of 90 percent and a specificity of 89.3 percent. The NLST had a sensitivity of 93.7 percent and a specificity of 76.5 percent.
“These findings suggest that with implementation of Lung-RADS, lung cancer screening has the potential to perform well in the broader US population,” Kaminetzky et al. concluded. “However, further study is needed to determine if the sensitivity and mortality benefit from LDCT screening found in the NLST is maintained in a real-world setting using Lung-RADS.”
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.