Table 1.
Baseline clinical and US imaging characteristics of patients with PTC.
| Characteristics | Total | Training dataset | Validation dataset | P value |
|---|---|---|---|---|
| n = 886 | n = 617 | n = 269 | ||
| Sex | ||||
| Male | 205 (23.1%) | 138 (22.4%) | 67 (24.9%) | |
| Female | 681 (76.9%) | 479 (77.6%) | 202 (75.1%) | 0.410 |
| Age (Y) | ||||
| Mean ± SD (range) | 43.4 ± 12.1 (23–77) | 43.5 ± 12.1 (25–77) | 43.2 ± 11.9 (23–76) | 0.994 |
| ≥55 | 151 (17.0%) | 106 (17.2%) | 45 (16.7%) | |
| <55 | 735 (83.0%) | 511 (82.8%) | 224 (83.3%) | 0.870 |
| BMI (kg/m2) | ||||
| Mean ± SD (range) | 24.2 ± 4.57 (11.13–38.67) | 24.10 ± 4.62 (13.13–37.27) | 24.41 ± 4.47 (11.13–38.67) | 0.930 |
| Normal | 481 (54.3%) | 342 (55.4%) | 139 (51.7%) | |
| Overweight | 405 (45.7%) | 275 (44.6%) | 130 (48.3%) | 0.302 |
| Diabetes | ||||
| Absence | 827 (93.3%) | 575 (93.2%) | 252 (93.7%) | |
| Presence | 59 (6.7%) | 42 (6.8%) | 17 (6.3%) | 0.789 |
| BRAF V600E mutation | ||||
| Negative | 172 (19.4%) | 125 (20.3%) | 47 (17.5%) | |
| Positive | 714 (80.6%) | 492 (79.7%) | 222 (82.5%) | 0.335 |
| CLT | ||||
| Absence | 612 (69.1%) | 434 (70.3%) | 178 (66.2%) | |
| Presence | 274 (30.9%) | 183 (29.7%) | 91 (33.8%) | 0.217 |
| Maximum tumor size (cm) | ||||
| Mean ± SD (range) | 1.21 ± 0.92 (0.11–8.53) | 1.31 ± 1.10 (0.11–8.53) | 1.23 ± 0.92 (0.12–7.90) | 0.134 |
| ≤1 | 505 (57.0%) | 348 (56.4%) | 157 (58.4%) | |
| >1 to ≤2 | 255 (28.8%) | 178 (28.8%) | 77 (28.6%) | |
| >2 to ≤4 | 103 (11.6%) | 74 (12.0%) | 29 (10.8%) | |
| >4 | 23 (2.6%) | 17 (2.8%) | 6 (2.2%) | 0.904 |
| The number of foci | ||||
| 1 | 600 (67.7%) | 416 (67.4%) | 184 (68.4%) | |
| 2 | 184 (20.8%) | 129 (20.9%) | 55 (20.4%) | |
| 3 or more | 102 (11.5%) | 72 (11.7%) | 30 (11.2%) | 0.956 |
| Multifocality | ||||
| Solitary | 600 (67.7%) | 416 (67.4%) | 184 (68.4%) | |
| Unilateral multifocality | 104 (11.7%) | 81 (13.1%) | 23 (8.6%) | |
| Bilateral multifocality | 182 (20.5%) | 120 (19.4%) | 62 (23.0%) | 0.103 |
| Location | ||||
| Upper | 296 (33.4%) | 203 (32.9%) | 93 (34.6%) | |
| Middle/Lower | 590 (66.6%) | 414 (67.1%) | 176 (65.4%) | 0.628 |
| Nodular composition | ||||
| Cystic or spongiform | 2 (0.2%) | 1 (0.2%) | 1 (0.4%) | |
| Mixed cystic and solid | 12 (1.4%) | 9 (1.5%) | 3 (1.1%) | |
| Solid | 872 (98.4%) | 607 (98.4%) | 265 (98.5%) | 0.777 |
| Echogenicity | ||||
| Anechoic | 3 (0.3%) | 2 (0.3%) | 1 (0.4%) | |
| Hyperechoic or isoechoic | 45 (5.1%) | 30 (4.9%) | 15 (5.6%) | |
| Hypoechoic | 816 (92.1%) | 570 (92.4%) | 246 (91.4%) | |
| Very hypoechoic | 22 (2.5%) | 15 (2.4%) | 7 (2.6%) | 0.971 |
| A/T | ||||
| ≤1 | 340 (38.4%) | 237 (38.4%) | 103 (38.3%) | |
| >1 | 546 (61.6%) | 380 (61.6%) | 166 (61.7%) | 0.973 |
| Margin | ||||
| Smooth | 561 (63.3%) | 400 (64.8%) | 161 (59.9%) | |
| Lobulated or irregular | 286 (32.3%) | 193 (31.3%) | 93 (34.6%) | |
| ETE | 39 (4.4%) | 24 (3.9%) | 15 (5.6%) | 0.276 |
| Echogenic foci | ||||
| None or large comet-tail artifacts | 320 (36.1%) | 221 (35.8%) | 99 (36.8%) | |
| Macrocalcifications | 45 (5.1%) | 33 (5.3%) | 12 (4.5%) | |
| Peripheral calcifications | 12 (1.4%) | 9 (1.5%) | 3 (1.1%) | |
| Punctate echogenic foci | 509 (57.4%) | 354 (57.4%) | 155 (57.6%) | 0.915 |
| US-reported LN status | ||||
| Negative | 638 (72.0%) | 433 (70.2%) | 205 (76.2%) | |
| Positive | 248 (28.0%) | 184 (29.8%) | 64 (23.8%) | 0.066 |
| CLNM | ||||
| Negative | 449 (50.7%) | 311 (50.4%) | 138 (51.3%) | |
| Positive | 437 (49.3%) | 306 (49.6%) | 131 (48.7%) | 0.806 |
| No. of removed LNs in CC | ||||
| Mean ± SD (range) | 7.8 ± 4.9 (2–35) | 7.8 ± 4.9 (3–35) | 7.7 ± 5.0 (2–32) | 0.848 |
| ≥6 | 737 (83.2%) | 516 (83.6%) | 221 (82.2%) | |
| <6 | 149 (16.8%) | 101 (16.4%) | 48 (17.8%) | 0.590 |
| No. of metastatic LNs in CC, Mean ± SD (range) | 2.6 ± 1.6 (0–15) | 2.6 ± 1.7 (0–12) | 2.5 ± 1.6 (0–15) | 0.364 |
US, Ultrasound; PTC, papillary thyroid carcinoma; Y, year; SD, standard deviation; BMI, body mass index; CLT, chronic lymphocytic thyroiditis; ETE, extrathyroidal extension; LN, lymph node; CLNM, central lymph node metastasis; CC, central compartment.