Table 1.
Demographic, clinical and semantic CT features of patients in the training and validation set
| Characteristic | Training set (n = 712) | p value | Validation set (n = 306) | p value | ||
|---|---|---|---|---|---|---|
| Preinvasive lesions (n = 97) | Invasive lesions (n = 615) | Preinvasive lesions (n = 42) | Invasive lesions (n = 264) | |||
| Gender | ||||||
| Male | 36 (37.1) | 209 (34.0) | 0.547 | 15 (35.7) | 98 (37.1) | 0.861 |
| Female | 61 (62.9) | 406 (66.0) | 27 (64.3) | 166 (62.9) | ||
| Age (years, average ± SD) | 53.5 ± 8.5 | 54.9 ± 9.5 | 0.064 | 52.1 ± 10.9 | 55.1 ± 9.5 | 0.082 |
| Having respiratory symptoms | ||||||
| Yes | 3 (3.1) | 66 (10.7) | 0.015 | 2 (4.8) | 32 (12.1) | 0.159 |
| No | 94 (96.9) | 549 (89.3) | 40 (95.2) | 232 (87.9) | ||
| BMI | 24.1 ± 3.1 | 24.2 ± 3.0 | 0.761 | 23.4 ± 2.5 | 24.4 ± 3.0 | 0.07 |
| Smoking history | ||||||
| Yes | 10 (10.3) | 97 (15.8) | 0.162 | 5 (11.9) | 43 (16.3) | 0.648 |
| No | 87 (89.7) | 518 (84.2) | 37 (88.1) | 221 (83.7) | ||
| Smoking index (pack-year) | 87.6 ± 386.3 | 93.9 ± 283.0 | 0.177 | 100.0 ± 338.0 | 78.4 ± 226.6 | 0.544 |
| Former lung cancer history | ||||||
| Yes | 2 (2.1) | 14 (2.3) | 1.000 | 0 (0) | 2 (0.8) | 1.000 |
| No | 95 (97.9) | 601 (97.7) | 42 (100) | 262 (99.2) | ||
| Former malignancy history except lung cancer | ||||||
| Yes | 4 (4.1) | 33 (5.4) | 0.806 | 0 (0) | 11 (4.2) | 0.372 |
| No | 93 (95.9) | 582 (94.6) | 42 (100) | 253 (95.8) | ||
| Former pulmonary benign disorders | ||||||
| Yes | 2 (2.1) | 31 (5.0) | 0.296 | 1 (2.4) | 7 (2.7) | 1.000 |
| No | 95 (97.9) | 584 (95.0) | 41 (97.6) | 257 (97.3) | ||
| Family history of lung cancer | ||||||
| Yes | 10 (10.3) | 66 (10.7) | 0.900 | 2 (4.8) | 28 (10.6) | 0.399 |
| No | 87 (89.7) | 549 (89.3) | 40 (95.2) | 236 (89.4) | ||
| Family history of malignancy except lung cancer | ||||||
| Yes | 17 (17.5) | 93 (15.1) | 0.543 | 7 (16.7) | 41 (15.5) | 0.851 |
| No | 80 (82.5) | 522 (84.9) | 35 (83.3) | 223 (84.5) | ||
| Abnormal tumor biomarker resultsa | ||||||
| Yes | 6 (6.2) | 99 (16.1) | 0.011 | 5 (11.9) | 31 (11.7) | 0.976 |
| No | 91 (93.8) | 516 (83.9) | 37 (88.1) | 233 (88.3) | ||
| Multiple nodules | ||||||
| Yes | 38 (39.2) | 309 (50.2) | 0.043 | 15 (35.7) | 130 (49.2) | 0.103 |
| No | 59 (60.8) | 306 (49.8) | 27 (64.3) | 134 (50.8) | ||
| Nodule density | ||||||
| pGGO | 81 (83.5) | 374 (60.8) | < 0.001 | 35 (83.3) | 163 (61.7) | 0.007 |
| mGGO | 16 (16.5) | 241 (39.2) | 7 (16.7) | 101 (38.3) | ||
| Border | ||||||
| Unclear | 12 (12.4) | 174 (28.3) | 0.001 | 3 (7.1) | 63 (23.9) | 0.014 |
| Clear | 85 (87.6) | 441 (71.7) | 39 (92.9) | 201 (76.1) | ||
| Lobulation sign | ||||||
| Yes | 10 (10.3) | 199 (32.4) | < 0.001 | 3 (7.1) | 65 (24.6) | 0.009 |
| No | 87 (89.7) | 416 (67.6) | 39 (9.3) | 199 (75.4) | ||
| Spiculation sign | ||||||
| Yes | 6 (6.2) | 104 (16.9) | 0.007 | 1 (2.4) | 35 (13.3) | 0.04 |
| No | 91 (93.8) | 511 (83.1) | 41 (97.6) | 229 (86.7) | ||
| Pleural indentation sign | ||||||
| Yes | 6 (6.2) | 106 (17.2) | 0.005 | 1 (2.4) | 44 (16.7) | 0.01 |
| No | 91 (93.8) | 509 (82.8) | 41 (97.6) | 220 (83.3) | ||
| Bubble sign | ||||||
| Yes | 8 (8.2) | 107 (17.4) | 0.023 | 4 (9.5) | 40 (15.2) | 0.478 |
| No | 89 (91.8) | 508 (82.6) | 38 (90.5) | 224 (84.8) | ||
| Vessel change | ||||||
| Yes | 14 (14.4) | 125 (20.3) | 0.174 | 4 (9.5) | 64 (24.2) | 0.044 |
| No | 83 (85.6) | 490 (79.7) | 38 (90.5) | 200 (75.8) | ||
| Maximum 2D diameter (mm, average ± SD) | 9.2 ± 3.2 | 12.6 ± 5.2 | < 0.001 | 8.9 ± 3.4 | 12.7 ± 5.1 | < 0.001 |
| Location | ||||||
| Left upper lobe | 20 (20.6) | 152 (24.7) | 0.277 | 12 (28.6) | 69 (26.1) | 0.670 |
| Left lower lobe | 21 (21.6) | 91 (14.8) | 7 (16.7) | 34 (12.9) | ||
| Right upper lobe | 39 (40.2) | 236 (38.4) | 16 (38.1) | 103 (39.0) | ||
| Right middle lobe | 2 (2.1) | 33 (5.4) | 3 (7.1) | 12 (4.5) | ||
| Right lower lobe | 15 (15.5) | 103 (16.7) | 4 (9.5) | 46 (17.4) | ||
| Rad-score | 0.9 ± 1.5 | 2.7 ± 1.3 | < 0.001 | 1.1 ± 1.2 | 2.8 ± 1.3 | < 0.001 |
BMI, body mass index; pGGO, pure ground-glass opacity nodule; mGGO, mixed ground-glass opacity nodule
aAn abnormal tumor biomarker result is defined as a higher blood concentration above the normal range of any of the following: carcinoembryonic antigen (CEA), CA-125 or CYFRA21-1