Longitudinal evolution of incidentally detected solitary pure ground-glass nodules on ct: Relation to clinical metrics

PURPOSE We aimed to assess the relation between basic clinical parameters and evolution of solitary pure ground-glass nodules (pGGN) in the lungs. METHODS Baseline and follow-up computed tomography (CT) of patients with solitary pGGN were selected and two radiologists independently reviewed CTs for nodule characterization. CT features of sol- itary pGGN were manually measured maximum diameter (D1) and its orthogonal diameter (D2), mean diameter (mD), D1 to D2 ratio as surrogate of roundness, and location according to lobar anatomy. Longitudinal changes were assessed and solitary pGGNs were classified as resolved or persisting. Persisting nodules were further classified as stable or grown according to an increase in mD of ≥2 mm or appearance of solid component. Baseline CT features of solitary pGGNs and clin- ical metrics of patients were compared between resolved and persisting nodules and, thereafter, between stable and grown lesions. RESULTS A total of 95 subjects with solitary pGGN were included. After a median 16-month follow-up, 20 nodules resolved, while 75 persisted. Among persisting nodules, 18 were grown and 57 were sta- ble. Grown nodules showed larger D1 and mD compared with stable pGGNs (P < 0.001). Subjects with grown nodules were older (P = 0.021). Logistic regression analyses showed higher likelihood of growth for nodules ≥10 mm (odds ratio [OR], 8.355; P = 0.001) and subjects older than 67 years (OR, 3.656; P = 0.034). CONCLUSION Nodules ≥10 mm in subjects older than 67 years showed higher likelihood of growth. These data could contribute to a more individual approach to the management of solitary pGGN.