Table 1. Comparison of nodule management protocols for three leading LDCT studies.
Nodule characteristics (attenuation, diameter, volume) | Recommended action | Interval findings | Recommended action | |||||
---|---|---|---|---|---|---|---|---|
Small | NLST | <4 mm dmax | 12 m LDCT | |||||
NEL | <50 mm3 without benign characteristics | |||||||
IE | Solid/ part-solid <5 mm dmean; | |||||||
non-solid: any size | ||||||||
Intermediate | NLST | Solid 4-10 mm dmax | 3-6 m LDCT (may vary up to 24 m according to level of suspicion) | No growth† | → | 12 m LDCT | ||
Growth <7 mm | → | 3-6 m LDCT or refer to pulmonologist | ||||||
Growth ≥7 mm | → | Refer to pulmonologist | ||||||
Pure GGO 4-10 mm dmax | 6-12 m LDCT | As per solid 4-10 mm nodules | ||||||
NEL | Solid: 50-500 mm3; | 3 m LDCT | Growth†† | → | Refer to pulmonologist | |||
Solid, pleural based: 5-10 mm | ||||||||
Mixed: GGO component: ≥8 mm dmean or solid component: 50-500 mm3 | ||||||||
Pure GGO: ≥8 mm dmean | ||||||||
IE | Solid/ part-solid 5-15 mm dmean | 3 m LDCT (preferred option) or Antibiotics & 3 m LDCT if infection possible or | Growth††† | → | Biopsy | |||
PET scan if solid/solid component >10 mm | PET scan negative | → | 3 m LDCT | |||||
Large | NLST | Solid >10 mm dmax | Refer to pulmonologist | |||||
Other suspicious finding | ||||||||
NEL | Solid: >500 mm3; | |||||||
Solid, pleural based: >10 mm | ||||||||
Mixed, solid component: >500 mm3 | ||||||||
IE | Solid/ Mixed >15 mm dmean |
Key: NLST-NLST, NEL-NELSON, IE-I-ELCAP; m, month; dmean, mean of maximal diameter and width viewed on same CT slice; dmax, maximal diameter on axial CT slice; PET, Positron-emission tomography; GGO, ground glass opacity attenuation nodule; Definitions of growth minimum significant change: †, >10% increase in diameter; ††, ≥25% increase in volume after at least a 3 months interval; †††, Minimum change in nodule diameter/solid component of part-solid nodules to define significant growth: for nodules <5 mm in diameter, ≥50%; for nodules 5-9 mm in diameter ≥30%; for nodules >10 mm in diameter ≥20%. Adapted from NLST (60) NELSON (52), I-ELCAP (61).