Table 2 Baseline characteristics of the training group and the validation group

0.478

 Age (years)

55.4 ± 10.6

56.7 ± 11.3

 Male sex

124 (46.3%)

22 (46.8%)

0.902

  A to C

51 (19.0%)

8 (17.0%)

  D or E

217 (81.0%)

39 (83.0%)

0.070

  Score 0–2 (≤50% of waking hours bed or chair bound)

103 (38.5%)

11 (23.4%)

  Score 3–4 (> 50% of waking hours bed or chair bound)

165 (61.5%)

36 (76.6%)

0.252

  Corpectomy or vertebrectomy with stabilization

117 (43.7%)

24 (51.1%)

  Decompression and stabilization

70 (26.1%)

13 (27.7%)

  Decompression alone

80 (29.9%)

9 (19.1%)

  Stabilization alone

1 (0.4%)

1 (2.1%)

0.136

  1 level

91 (34.0%)

12 (25.5%)

  2 levels

35 (13.1%)

3 (6.4%)

   ≥ 3 levels

142 (53.0%)

32 (68.1%)

0.812

  None

148 (55.2%)

28 (59.6%)

  Liver or lung

99 (36.9%)

19 (40.4%)

  Brain

30 (11.2%)

4 (8.5%)

  Prior local radiotherapy

26 (9.7%)

4 (8.5%)

1.000

  Previous systemic therapy

147 (54.9%)

26 (55.3%)

1.000

 WBC count (×10³/μL)

6.73 ± 3.04

7.06 ± 3.27

0.513

 Hemoglobin (g/dL)

12.3 ± 1.8

12.2 ± 2.0

0.899

 Platelet count (×10³/μL)

226.6 ± 76.8

230.4 ± 114.1

0.828

 Neutrophil count (×10³/μL)

4.86 ± 2.58

5.03 ± 2.88

0.708

 Lymphocyte count (×10³/μL)

1.38 ± 0.71

1.47 ± 0.73

0.459

 Albumin (g/dL)

4.0 ± 0.5

3.9 ± 0.5

0.644

 Alkaline phosphatase (IU/L)

124.0 ± 148.6

103.8 ± 47.3

0.079

 Creatinine (mg/dL)

0.71 ± 0.21

0.66 ± 0.27

0.214

 Total Bilirubin (mg/dL)

10.5 ± 6.0

12.4 ± 8.3

0.152

 Ca2+ (mg/dL)

2.3 ± 0.7

2.3 ± 0.2

0.971

 INR

0.97 ± 0.13

0.99 ± 0.09

0.209

 NLR

4.9 ± 4.7

4.3 ± 3.3

0.274

 PLR

216.6 ± 157.8

200.5 ± 177.9

0.564