The 2017 tables
Size is the average of the long and short axis on the same image (axial, or coronal/sagittal if larger), rounded to the nearest millimetre. Ranges rather than fixed intervals are deliberate: the guideline leaves room for risk factors and patient preference.
| Solid nodules | < 6 mm | 6–8 mm | > 8 mm |
|---|
| Single, low risk | No routine follow-up | CT at 6–12 months, then consider CT at 18–24 months | Consider CT at 3 months, PET/CT, or tissue sampling |
| Single, high risk | Optional CT at 12 months | CT at 6–12 months, then CT at 18–24 months | Consider CT at 3 months, PET/CT, or tissue sampling |
| Multiple, low risk | No routine follow-up | CT at 3–6 months, then consider CT at 18–24 months | CT at 3–6 months, then consider CT at 18–24 months |
| Multiple, high risk | Optional CT at 12 months | CT at 3–6 months, then CT at 18–24 months | CT at 3–6 months, then CT at 18–24 months |
| Subsolid nodules | < 6 mm | ≥ 6 mm |
|---|
| Single ground-glass | No routine follow-up (consider 2 and 4 years if suspicious) | CT at 6–12 months to confirm persistence, then every 2 years until 5 years |
| Single part-solid | No routine follow-up | CT at 3–6 months to confirm persistence; if unchanged and the solid component stays < 6 mm, annual CT for 5 years. A solid component ≥ 6 mm is highly suspicious; > 8 mm, growing, or suspicious morphology → PET/CT, biopsy or resection |
| Multiple | CT at 3–6 months; if stable, consider CT at 2 and 4 years | CT at 3–6 months; then manage by the most suspicious nodule |
- High risk (ACCP definition adopted by Fleischner): heavy smoking, older age, family history, upper-lobe location, spiculation, emphysema or pulmonary fibrosis.
- Dates are counted from the CT date. For "every 2 years until 5 years" the calculator lists windows at about 3 and 5 years after the first confirmatory scan.
- Perifissural or subpleural triangular nodules with typical intrapulmonary lymph node morphology need no follow-up even when > 6 mm.
References
- MacMahon H, Naidich DP, Goo JM, et al. Guidelines for Management of Incidental Pulmonary Nodules Detected on CT Images: From the Fleischner Society 2017. Radiology. 2017;284(1):228–243.
doi:10.1148/radiol.2017161659
- Bankier AA, MacMahon H, Goo JM, Rubin GD, Schaefer-Prokop CM, Naidich DP. Recommendations for Measuring Pulmonary Nodules at CT: A Statement from the Fleischner Society. Radiology. 2017;285(2):584–600.
doi:10.1148/radiol.2017162894