Fleischner Society pulmonary nodule follow-up calculator
Enter the nodule characteristics to get the Fleischner Society 2017 follow-up recommendation for an incidentally detected pulmonary nodule. The complete decision table is reproduced below the calculator, so you can check the branch you landed on.
Solid nodules — full decision table
| Size | Solitary, low risk | Solitary, high risk | Multiple, low risk | Multiple, high risk |
|---|---|---|---|---|
| <6 mm | No routine follow-up | Optional CT at 12 months | No routine follow-up | Optional CT at 12 months |
| 6-8 mm | CT at 6-12 mo, then consider CT at 18-24 mo | CT at 6-12 mo, then CT at 18-24 mo | CT at 3-6 mo, then consider CT at 18-24 mo | CT at 3-6 mo, then CT at 18-24 mo |
| >8 mm | Consider CT at 3 mo, PET/CT, or tissue sampling | Consider CT at 3 mo, PET/CT, or tissue sampling | CT at 3-6 mo, then consider CT at 18-24 mo | CT at 3-6 mo, then CT at 18-24 mo |
Subsolid nodules — full decision table
| Type | Size | Solitary | Multiple |
|---|---|---|---|
| Ground-glass | <6 mm | No routine follow-up | CT at 3-6 mo; if stable, consider CT at 2 and 4 years |
| Ground-glass | ≥6 mm | CT at 6-12 mo to confirm persistence, then CT every 2 years until 5 years | CT at 3-6 mo; management based on the most suspicious nodule |
| Part-solid | <6 mm | No routine follow-up | CT at 3-6 mo; if stable, consider CT at 2 and 4 years |
| Part-solid | ≥6 mm | CT at 3-6 mo to confirm persistence. Solid component <6 mm: annual CT for 5 years. Solid component ≥6 mm: consider PET/CT, biopsy, or resection | CT at 3-6 mo; management based on the most suspicious nodule |
When Fleischner does not apply
- Patients under 35 years of age
- Lung cancer screening CT (use Lung-RADS instead)
- Patients with a known primary malignancy (risk of metastases)
- Immunocompromised patients
What counts as high risk
High risk means an elevated probability of malignancy — heavy smoking history, older age, upper-lobe location, spiculated margin, emphysema or fibrosis, or a family history of lung cancer. Fleischner 2017 uses the ACCP risk categories (low <5%, high >65%), with intermediate-risk patients managed as high risk.
Measuring the nodule
Fleischner 2017 uses the average of the long-axis and short-axis diameters, measured on the same transverse, coronal or sagittal section, rounded to the nearest millimetre. For part-solid nodules, report the maximal diameter of the solid component. The size thresholds refer to this mean diameter, not the single longest dimension.
Related
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