Observation of Nonsolid Lung Nodules By CT Is Safe

Patients with nonsolid lung nodules can be safely followed with low-dose CT at 12-month intervals, according to a study published in Radiology.

Researchers from the United States and China studied the frequency of identifying nonsolid nodules, diagnosing lung cancer manifesting as such nodules, and the long-term outcome after treatment among 57,496 patients who participated in the International Early Lung Cancer Action Program.

The participants underwent baseline and annual repeat screenings, and the researchers evaluated the prevalence of nonsolid nodules and their effect on long-term outcomes. If a participant had more than one nonsolid nodule, the focus was on the largest.

"Nonsolid nodules could be due to inflammation, infection or fibrosis, but could also be cancerous or a precursor of cancer," co-author Claudia I. Henschke, PhD, MD, department of radiology at Mount Sinai School of Medicine in New York City, said in a release. "For screening, we have to define which nodules need further workup and how quickly we have to do that workup."

If a nodule increased in overall size or developed solid components, it was deemed to have grown. The findings showed that a nonsolid nodule was identified in 2,392 (4.2%) of the baseline screenings, which were ultimately diagnosed among 73 as adenocarcinoma.[[{"type":"media","view_mode":"media_crop","fid":"38866","attributes":{"alt":"","class":"media-image media-image-right","id":"media_crop_3893409506277","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"3902","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"height: 148px; width: 300px; border-width: 0px; border-style: solid; margin: 1px; float: right;","title":"CT images in a 68-year-old smoker show (a) a nonsolid nodule (17 x 13 mm) in the lef tupper lobe at baseline screening, (b) the nodule remained nonsolid at follow-up 2 years later, and (c) a solid component at follow-up 9 years later. At that time, it was resected, and the final diagnosis was 2.1-cm invasive adenocarcinoma. Image courtesy of Radiology. ©RSNA, 2015.","typeof":"foaf:Image"}}]]

A new nonsolid nodule was identified in 485 (0.7%) of 64,677 annual repeat screenings; 11 were diagnosed with stage I adenocarcinoma. Median time to treatment was 19 months and surgery was 100% curative in all cases, with a median follow-up since diagnosis of more than six years.

Treatment:

In 22 cases, the nonsolid nodule developed a solid component prior to treatment. Median transition time from nonsolid to part-solid was 25 months. No cancers occurred in new nodules 15 millimeters or larger in diameter.

"Many recommendations had been fairly aggressive with respect to nonsolid nodules," co-author David F. Yankelevitz, MD, also from Mount Sinai hospital, said in the same release. "These results show that there is no reason to be aggressive in pursuit of cancer, so long as the nodules stay in this nonsolid form."