Table 1 Clinical characteristics of the training, validation, and test datasets
Characteristics | Training and validation sets | Test set A | Test set B |
|---|---|---|---|
Number | 848 | 94 | 89 |
 Lymph node metastasis | 400 (47.2%) | 47 (50.0%) | 44 (49.4%) |
 No lymph node metastasis | 448 (52.8%) | 47 (50.0%) | 45 (50.6%) |
Age, mean ± SD, years | 42.61 ± 10.42 | 43.78 ± 9.27 | 41.53 ± 10.94 |
 ≤ 45 | 553 (65.2%) | 55 (58.5%) | 55 (61.8%) |
 > 45 | 295 (34.8%) | 39 (41.5%) | 34 (38.2%) |
Gender | |||
 Female | 675 (79.6%) | 78 (83.0%) | 72 (80.9%) |
 Male | 173 (20.4%) | 16 (17.0%) | 17 (19.1%) |
Primary site | |||
 Right lobe | 413 (48.7%) | 48 (51.1%) | 44 (49.4%) |
 Left lobe | 420 (49.5%) | 43 (45.7%) | 43 (48.3%) |
 Isthmus | 15 (1.8%) | 3 (3.2%) | 2 (2.2%) |
Metastatic site | |||
 Central lymph node | 271 (67.8%) | 30 (63.8%) | 28 (64.0%) |
 Central and lateral lymph node | 89 (22.3%) | 12 (24.5%) | 11 (24.7%) |
 Lateral lymph node | 40 (9.9%) | 5 (11.7%) | 5 (11.2%) |
Prophylactic CND | |||
 Tumor size > 4 cm | 359 (42.3%) | 41 (43.6%) | 27 (30.3%) |
 Extrathyroidal extension (ETE) | 125 (14.7%) | 25 (26.6%) | 34 (38.2%) |
 ETE and Tumor size > 4 cm | 364 (43.0%) | 28 (29.8%) | 28 (31.5%) |
TI-RADS category | |||
 4A category | 29 (3.4%) | 4 (4.3%) | 5 (5.6%) |
 4B category | 175 (20.6%) | 22 (23.7%) | 22 (24.7%) |
 4C category | 384 (45.3%) | 37 (38.9%) | 38 (42.7%) |
 5 category | 260 (30.7%) | 31 (32.9%) | 24 (27.0%) |
US size, mean ± SD, mm | 12.74 ± 6.58 | 10.93 ± 5.91 | 11.47 ± 6.35 |