Characteristics of non-resolving new solid nodules that persisted as solid nodule at first follow-up or regular screening after initial detection (n=454; 429 benign nodules and 25 lung cancer nodules)
| All new solid nodules that persisted at first LDCT after detection, n=454 (100%) | Subsequent LDCT within 120 days, n=210 (46.3%) (short-term follow-up) | Subsequent LDCT after 120 days, n=244 (53.7%) | |||||||
| Benign | Lung cancer | P values | Benign | Lung cancer | P values | Benign | Lung cancer | P values | |
| 429/454 (94.5%) | 25/454 (5.5%) | 193/210 (91.9%) | 17/210 (8.1%) | 236/244 (96.7%) | 8/244 (3.3%) | ||||
| Days between scans | |||||||||
| Median (IQR) | 347 (50–724) | 56 (46–325) | 0.006 | 49 (43–62) | 49 (42–56) | 0.887 | 719 (370–797) | 347 (323–640) | 0.011 |
| Volume (mm3) | |||||||||
| <50 | 296/429 (69.0%) | 1/25 (4.0%) | 85/193 (44.0%) | 1/17 (5.9%) | 216/236 (89.4%) | 0/8 (0.0%) | |||
| 50 to <500 | 120/429 (28.0%) | 22/25 (88.0%) | 95/193 (49.2%) | 14/17 (82.4%) | 25/236 (10.6%) | 8/8 (100%) | |||
| ≥500 | 13/429 (3.0%) | 2/25 (8.0%) | 13/193 (6.7%) | 2/17 (11.8%) | 0/236 (0.0%) | 0/8 (0.0%) | |||
| Median (IQR) | 28 (17–63) | 135 (83–331) | <0.0001 | 63 (33–126) | 203 (95–362) | 0.0003 | 20 (15–30) | 94 (79–248) | <0.0001 |
| VDT (days) | |||||||||
| Median (IQR) | ∞ (1845–∞) | 219 (129–298) | <0.0001 | ∞ (1346–∞) | 155 (116–294) | <0.0001 | ∞ (1969–∞) | 254 (227–362) | <0.0001 |
| Simulated mean diameter* (mm) | |||||||||
| Median (IQR) | 4.0 (3.2–5.8) | 7.2 (5.5–9.1) | <0.0001 | 5.6 (4.0–7.4) | 8.0 (5.4–10.9) | 0.014 | 3.5 (3.0–4.1) | 7.0 (5.5–8.5) | <0.0001 |
| Nodule was below detection limit in retrospect | 176/42 (41.0%) | 4/25 (16.0%) | 0.012 | 17/193 (8.8%) | 1/17 (5.9%) | 0.999 | 159/236 (67.4%) | 3/8 (37.5%) | 0.127 |
*Diameters were simulated from computer-generated volume measurements, based on three-dimensional voxels.
∞, decreased size; LDCT, low-dose CT; VDT, volume doubling time.