Using the American College of Radiology’s Lung-RADS standards improved the positive predictive value of CT lung screening by a factor of 2.5, according to a study published in the August issue of the Journal of the American College of Radiology.

Brady J. McKee, MD, of the Lahey Hospital and Medical Center in Burlington, Mass., and colleagues used Lung-RADS to retroactively reclassify clinical CT lung screening examinations done between January 2012 and May 2014. They then recalculated the positive rate, number of false-negative findings, and positive predictive value.

Applying ACR Lung-RADS structured reporting increased the positive predictive value for diagnosed malignancy in 1,603 patients with follow-up from 6.9 percent to 17.3 percent.

The increase in positive predictive value did not raise the number of examinations with false-negative results, according to the researchers.

Use of Lung-RADS reduced the overall positive rate from 27.6 percent to 10.6 percent.

No false negatives were present in 152 patients reclassified as benign that had follow-up of longer than one year. “This observation supports the notion that it is safe to follow solid nodules <6 mm and nonsolid nodules <20 mm in high-risk patients with annual CT surveillance,” wrote McKee and colleagues.