SIZE less than or equal to 4 mm:
Low-risk patient - no follow-up needed.
High-risk patient - follow-up CT at 12 months, if unchanged no further follow-up.
SIZE greater than 4 mm - 6 mm:
Low-risk patient - follow-up CT at 12 months; if unchanged, no further follow-up.
High-risk patient - initial follow-up CT at 6-12 months, then at 18-24 months if no change.
SIZE greater than 6 mm - 8 mm:
Low-risk patient - initial follow-up CT at 6-12 months then at 18-24 months if no change.
High-risk patient - initial follow-up CT at 3-6 months, and at 9-12 months and 24 months if no change.
SIZE greater than 8 mm:
Low-risk patient – options include follow-up CT at around 3, 9 and 24 months, PET, and/or biopsy.
High-risk patient - same as for low risk the patient.
KNOWN OR SUSPECTED MALIGNANCY:
The follow-up of pulmonary nodules in patients known to have or suspected of having malignant disease should be based on the referring physician's discretion, specific to the clinical situation.
PATIENTS LESS 35 YEARS OF AGE:
Unless there is a known primary cancer multiple follow-up studies for small incidentally detected nodule(s) should be avoided in the patients. In such cases, a single low dose follow-up CT scan in 6-12 months should be considered.
Ground-glass or partially solid nodules may require longer follow-up to exclude an indolent adenocarcinoma.