Table 3 Univariate and multivariable analysis for factors influencing intracranial failure-free survival

Sex

Male

39

0.90 (0.41–1.95)

0.780

Female

24

–

–

Year of diagnosis of BM

 ≥ 2011

11

0.77 (0.31–1.90)

0.568

 < 2011

52

–

–

Number of BM before WBRT

 > 10

9

0.71 (0.20–2.58)

0.603

5–10

32

0.56 (0.25–1.27)

0.165

1–4

18

–

–

CNS progression prior to WBRT

No

23

1.55 (0.67–3.59)

0.302

Yes

33

–

–

Extracranial metastases

Yes

43

1.36 (0.62–2.98)

0.441

No

20

–

–

KPS

 > 80

27

0.50 (0.24–1.06)

0.072

0.53 (0.19–1.45)

0.214

 ≤ 80

36

–

–

–

–

ECOG performance status

2–3

16

2.22 (0.72–6.84)

0.166

1.00 (0.21–4.69)

1.000

1

33

3.54 (1.22–10.23)

0.020

2.80 (0.79–9.95)

0.110

0

14

–

–

–

–

Temozolomide

Yes

33

1.14 (0.54–2.39)

0.728

No

30

–

–

Interleukin-2

Yes

10

0.94 (0.36–2.47)

0.905

No

53

–

–

Interferon

Yes

19

1.10 (0.51–2.39)

0.805

No

44

–

–

BRAF inhibitor

Yes

8

0.79 (0.30–2.10)

0.640

No

55

–

–

MEK inhibitor

Yes

2

0.97 (0.23–4.16)

0.971

No

60

–

–

Concurrent ipilimumab/nivolumab

Yes

2

2.14 (0.50–9.12)

0.305

No

61

–

–

Post-WBRT radionecrosis

Yes

10

0.61 (0.21–1.76)

0.358

No

53

–

–

Post-WBRT intralesional hemorrhage

Yes

20

2.24 (1.07–4.69)

0.033

2.76 (1.25–6.07)

0.012

No

43

–

–

–

–

Post-WBRT memory deficits

Yes

12

0.65 (0.26–1.61)

0.354

No

51

–

–