CT Effectively Tracks Nonsolid Lung Nodules at 12-Month Intervals

June 17, 2015 - Computed tomography (CT) safely tracked nonsolid nodules of any size in the lung can at 12-month intervals to assess transition to part-solid, according to a study1 published in Radiology.

As part of the International Early Lung CancerAction Program, researchers designed a study to address the frequency of identifying nonsolid nodules, diagnosing lung cancer manifesting as such nodules, and the long-term outcome after treatment in a prospective cohort. Baseline and subsequent annual repeat CT screenings were performed on 57,496 patients who participated in the study. The frequency of participants with nonsolid nodules, the course of the nodule at follow-up, and the resulting diagnoses of lung cancer, treatment and outcome are given separately for baseline andannual repeat rounds of screening.

In 2,392 (4.2%) of the baseline screenings, a nonsolid nodule was identified, and pathologic pursuit led to the diagnosis of 73 cases of adenocarcinoma. A new nonsolid nodule was identified in 485 (0.7%) of 64,677 annual repeat screenings, and 11 had a diagnosis of stage I adenocarcinoma; none were in nodules 15-mm or larger in diameter. Nonsolid nodules resolved or decreased more frequently in annual repeat than in baseline rounds, 66% vs 26%. Treatment of the cases of lung cancer was with lobectomy in 55, bilobectomy in two, sublobar resection in 26, and radiation therapy in one. Median time to treatment was 19 months. Surgery was 100% curative in all cases, regardless of the time to treatment. A solid component had developed in 22 cases prior to treatment, and the median transition time from nonsolid to part-solid was 25 months. The lung cancer-survival rate was 100% with median follow-up since diagnosis of 78 months (IQR, 45-122 months).

Based on the results, the researchers concluded that nonsolid nodules of any size can be safely followed with CT at 12-month intervals to assess transition to part-solid.

ACC nodules - metastases with a greyish, nonsolid, low alighted or shady appearance.2


1. Yankelevitz DF, et al. CT screening for lung cancer: Nonsolid nodules in baseline and annual repeat rounds. Radiology 2015; DOI: 10.1148/radiol.2015142554.

2. How to interpret CT scans of the lung. http://www.website-go.com/acc/