Table 2 The Fleischner society recommendations for the follow-up and management of solid pulmonary nodules smaller than 8 mm detected incidentally in persons 35 years of age or older – adapted from reference [50]

Nodule size: ≤ 4 mm

 • Low risk^a : No follow-up

 • High risk^b : Follow-up CT at 12 months and if no change, no further follow-up required

Nodule size: >4 – 6 mm

 • Low risk^a : Follow-up CT at 12 months and if no change, no further follow-up required

 • High risk^b : Initial follow-up CT at 6–12 months and then at 18–24 months if no change

Nodule size: >6 – 8 mm

 • Low risk^a : Initial follow-up CT at 6–12 months and then at 18–24 months if no change

 • High risk^b : Initial follow-up CT at 3–6 months and then at 9–12 and 24 months if no change

Nodule size: >8 mm

 • Follow-up CTs at around 3, 9 and 24 months

 or

 • Dynamic contrast enhanced CT, PET-CT, and/or biopsy