Fleischner Society Guidelines for Management of Incidental Pulmonary Nodules
Solid Nodule(s)
Single Nodule
<6 mm (<100 mm³)
Low-risk patients: No follow up required.
High-risk patients: Optional CT at 12 months (especially if in upper lobe).
6-8 mm (100-250 mm³)
Low-risk patients: CT at 6-12 months, then consider CT at 18-24 months.
High-risk patients: CT at 6-12 months, then follow up CT at 18-24 months.
>8 mm (>250 mm³)
Low-risk patients and high-risk patients: CT at 3 months, PET-CT, or tissue sampling.
Multiple Nodules
<6 mm (<100 mm³)
Low-risk patients: No follow up required.
High-risk patients: Optional CT at 12 months.
6-8 mm (100-250 mm³)
Low-risk patients: CT at 3-6 months, then consider CT at 18-24 months.
High-risk patients: CT at 3-6 months, then follow up CT at 18-24 months.
>8 mm (>250 mm³)
Low-risk patients: CT at 3-6 months, then consider CT at 18-24 months.
High-risk patients: CT at 3-6 months, then follow up CT at 18-24 months.
Subsolid Nodule(s)
Single Nodule
Single ground glass nodule <6 mm (<100 mm³)
No follow up required.
Single ground glass nodule ≥6 mm (>100 mm³)
CT at 6-12 months, then if persistent, CT every 2 years until 5 years.
Single part-solid nodule ≥6 mm (>100 mm³)
CT at 3-6 months, then if persistent and solid component remains <6 mm, continue annual CT follow-ups for up to 5 years.
Multiple Nodules
Multiple subsolid nodules <6 mm (<100 mm³)
CT at 3-6 months, then if stable consider CT at 2 and 4 years in high-risk patients.
Multiple subsolid nodules ≥6 mm (>100 mm³)
CT at 3-6 months, then subsequent management based on the most suspicious nodule(s).
These recommendations do not apply to lung cancer screening, patients with known history of a primary cancer or immunosuppression, or patients younger than 35 years.
Reference: MacMahon H, Naidich D, Goo J et al. Guidelines for Management of Incidental Pulmonary Nodules Detected on CT Images: From the Fleischner Society 2017. Radiology. 2017;284(1):228-43.
doi:10.1148/radiol.2017161659