Table 3. Diagnostic Follow-up of Positive Screening Results in the Three Screening Rounds*.
| Variable | Low-Dose CT | Chest Radiography | ||||||
|---|---|---|---|---|---|---|---|---|
| T0 | T1 | T2 | Total | T0 | T1 | T2 | Total | |
| number (percent) | ||||||||
| Total positive tests | 7191 (100.0) | 6901 (100.0) | 4054 (100.0) | 18,146 (100.0) | 2387 (100.0) | 1482 (100.0) | 1174 (100.0) | 5043 (100.0) |
| Lung cancer confirmed | 270 (3.8) | 168 (2.4) | 211 (5.2) | 649 (3.6) | 136 (5.7) | 65 (4.4) | 78 (6.6) | 279 (5.5) |
| Lung cancer not confirmed† | 6921 (96.2) | 6733 (97.6) | 3843 (94.8) | 17,497 (96.4) | 2251 (94.3) | 1417 (95.6) | 1096 (93.4) | 4764 (94.5) |
| Positive screening results with complete diagnostic follow-up information | 7049 (100.0) | 6740 (100.0) | 3913 (100.0) | 17,702 (100.0) | 2348 (100.0) | 1456 (100.0) | 1149 (100.0) | 4953 (100.0) |
| Any diagnostic follow-up | 6369 (90.4) | 3866 (57.4) | 2522 (64.5) | 12,757 (72.1) | 2176 (92.7) | 1078 (74.0) | 957 (83.3) | 4211 (85.0) |
| Clinical procedure | 5089 (72.2) | 3190 (47.3) | 2151 (55.0) | 10,430 (58.9) | 1414 (60.2) | 723 (49.7) | 658 (57.3) | 2795 (56.4) |
| Imaging examination | 5717 (81.1) | 2520 (37.4) | 2009 (51.3) | 10,246 (57.9) | 2010 (85.6) | 968 (66.5) | 906 (78.9) | 3884 (78.4) |
| Chest radiography | 1284 (18.2) | 613 (9.1) | 650 (16.6) | 2,547 (14.4) | 867 (36.9) | 381 (26.2) | 365 (31.8) | 1613 (32.6) |
| Chest CT | 5153 (73.1) | 2046 (30.4) | 1608 (41.1) | 8,807 (49.8) | 1546 (65.8) | 745 (51.2) | 712 (62.0) | 3003 (60.6) |
| FDG PET or FDG PET-CT | 728 (10.3) | 350 (5.2) | 393 (10.0) | 1,471 (8.3) | 179 (7.6) | 105 (7.2) | 113 (9.8) | 397 (8.0) |
| Percutaneous cytologic examination or biopsy | 155 (2.2) | 74 (1.1) | 93 (2.4) | 322 (1.8) | 83 (3.5) | 37 (2.5) | 52 (4.5) | 172 (3.5) |
| Transthoracic | 120 (1.7) | 60 (0.9) | 74 (1.9) | 254 (1.4) | 67 (2.9) | 31 (2.1) | 43 (3.7) | 141 (2.8) |
| Extra thoracic | 39 (0.6) | 17 (0.3) | 24 (0.6) | 80 (0.5) | 20 (0.9) | 6 (0.4) | 13 (1.1) | 39 (0.8) |
| Bronchoscopy | 306 (4.3) | 178 (2.6) | 187 (4.8) | 671 (3.8) | 107 (4.6) | 56 (3.8) | 62 (5.4) | 225 (4.5) |
| With neither biopsy nor cytologic testing | 126 (1.8) | 95 (1.4) | 99 (2.5) | 320 (1.8) | 45 (1.9) | 19 (1.3) | 32 (2.8) | 96 (1.9) |
| With biopsy or cytologic testing | 194 (2.8) | 95 (1.4) | 102 (2.6) | 391 (2.2) | 74 (3.2) | 40 (2.7) | 36 (3.1) | 150 (3.0) |
| Surgical procedure | 297 (4.2) | 197 (2.9) | 219 (5.6) | 713 (4.0) | 121 (5.2) | 51 (3.5) | 67 (5.8) | 239 (4.8) |
| Mediastinoscopy or mediastinotomy | 60 (0.9) | 32 (0.5) | 25 (0.6) | 117 (0.7) | 22 (0.9) | 12 (0.8) | 21 (1.8) | 55 (1.1) |
| Thoracoscopy | 82 (1.2) | 56 (0.8) | 96 (2.5) | 234 (1.3) | 22 (0.9) | 11 (0.8) | 20 (1.7) | 53 (1.1) |
| Thoracotomy | 197 (2.8) | 148 (2.2) | 164 (4.2) | 509 (2.9) | 96 (4.1) | 44 (3.0) | 44 (3.8) | 184 (3.7) |
| Other procedures | 168 (2.4) | 96 (1.4) | 63 (1.6) | 327 (1.8) | 55 (2.3) | 33 (2.3) | 34 (3.0) | 122 (2.5) |
*
The screenings were performed at 1-year intervals, with the first screening (T0) performed soon after the time of randomization. FDG PET denotes 18F-fluorodeoxyglucose positron-emission tomography.
†
Positive tests with incomplete information on diagnostic follow-up are included in this category (142 at T0, 161 at Tl, and 141 at T2 in the low-dose CT group and 39 at T0, 26 at Tl, and 25 at T2 in the radiography group).