Table 1 Patient characteristics of the training and testing cohorts

n

1732

578

302

Age, mean ± SD, years

44.12 ± 11.17

43.91 ± 11.22

46.56 ± 11.78

Gender, n

Female

1334 (77.0)

435 (75.3)

224 (74.2)

Male

398 (23.0)

143 (24.7)

78 (25.8)

Tumor size (cm)

1.45 ± 0.85

1.42 ± 0.75

1.08 ± 0.78

Tumor location

Left lobe

798 (46.1)

249 (43.1)

152 (50.3)

Right lobe

880 (50.8)

313 (54.1)

143 (47.4)

Isthmus

54 (3.1)

16 (2.8)

7 (2.3)

Tumor position

Upper pole

528 (30.5)

186 (32.2)

36 (11.9)

Middle pole

432 (24.9)

127 (22.0)

134 (44.4)

Lower pole

722 (41.7)

265 (45.8)

132 (43.7)

Composition

Mixed cystic and solid

16 (0.9)

8 (1.4)

9 (3.0)

Solid

1716 (99.1)

570 (98.6)

293 (97.0)

Internal echo

Hyper or isoechoic

25 (1.4)

10 (1.7)

6(1.9)

Hypoechoic

1184 (68.4)

398 (68.9)

289(95.6)

Markedly hypoechoic

523 (30.2)

170 (29.4)

7(2.3)

Margins

Well-defined

127 (7.3)

32 (5.5)

48 (15.9)

Ill-defined

1605 (92.7)

546 (94.5)

254 (84.1)

Shape

A/T < 1

423 (24.4)

125 (21.6)

111 (36.8)

A/T ≥ 1

1309 (75.6)

453 (78.4)

191 (63.2)

Microcalcification

No

361 (20.8)

102 (17.6)

101 (33.4)

Yes

1371 (79.2)

476 (82.4)

201 (66.6)

Vascularization (blood flow)

0

1193 (68.9)

410 (70.9)

5 (1.7)

1

330 (19.0)

115 (19.9)

197 (65.2)

2

157 (9.1)

40 (6.9)

65 (21.5)

3

52 (3.0)

13 (2.3)

35 (11.6)

Abutment/perimeter

≤ 0.25

789 (45.6)

280 (48.4)

229 (75.8)

> 0.25

943 (54.4)

298 (51.6)

73 (24.2)

Mulifocality

No

1102 (63.6)

355 (61.4)

176 (58.3)

Yes

630 (36.4)

223 (38.6)

126 (41.7)

Hashimoto thyroiditis

Negative

1335 (77.1)

447 (77.3)

263 (87.1)

Positive

397 (22.9)

131 (22.7)

39 (12.9)

BRAF V600E mutation

No

246 (14.2)

70 (12.1)

NA

Yes

1486 (85.8)

508 (87.9)

NA

LLNM status in pathology

Non-LLNM

1358 (78.4)

460 (79.6)

230 (76.2)

LLNM

374 (21.6)

118 (20.4)

72 (23.8)