Table 1

Overview of the nodules detected in the scans performed in the fourth screening round

nPer cent
Total scans performed in round 45380100.0
 Scans with nodules250746.6
 Scans without nodules287353.4
Total nodules detected on scans performed in round 45336100.0
Nodule size category†
 NODCAT I*
  Benign2544.8
 NODCAT II**
  Non-significant small305757.3
 NODCAT III***
  Indeterminate187535.2
 NODCAT IV****
  Potentially malignant1492.8
Nodule growth category†
   GROWCAT§ A‡234898.1
   GROWCAT§ B‡‡140.6
   GROWCAT§ C‡‡‡291.3
Type
 Solid501293.9
 Partial solid390.7
 Non-solid470.9
 Disappeared nodules1613.0
 Calcified/benign971.6
Location
 Right lung§310958.3
 Left lung222741.7

  • *NODCAT I: Nodule with benign characteristics such as benign calcification patterns or fat depositions.

  • **NODCAT II: Solid nodules with volume <50 mm³; Pleural-based solid nodules with minimum diameter <5 mm; Non-solid component part solid nodule with average diameter <8 mm; Solid component part solid nodule with volume <50 mm³; Non-solid nodules with average diameter <8 mm.

  • ***NODCAT III: Solid nodules with volume 50–500 mm³; Pleural-based solid nodules with minimum diameter 5–10 mm; Non-solid component part solid nodule with average diameter ≥8 mm; Solid component part solid nodule with volume 50–500 mm³; Non-solid nodules with average diameter ≥8 mm.

  • ****NODCAT IV: Pleural-based solid nodules with minimum diameter >10 mm; Solid component part solid nodule with volume >500 mm³.

  • †One nodule without outcome.

  • ‡GROWCAT A: Percentage volume change ≥25% and VDT >600 days.

  • ‡‡GROWCAT B: Percentage volume change ≥25% and VDT 400–600 days.

  • ‡‡‡GROWCAT C: Percentage volume change ≥25% and VDT <400 days; New solid component in previously non-solid nodule.

  • §One nodule was located in the trachea.

  • GROWCAT, nodule growth category; NODCAT, nodule size category; VDT, volume doubling time.