Table 4 Cumulative incidence local progression (CILP), distant brain failure (DBF), disease free survival (DFS) and overall survival (OS)

Cumulative incidence local progression

 Median time (months)

n.r

n.r

n.r

–

 1-year (%)

1.8 (0.9–3.5)

0.4 (0.1–3.0)

3.3 (1.6–6.8)

–

 2-year (%)

2.5 (1.4–4.4)

0.9 (0.2–3.4)

4.2 (2.2–8.0)

–

 3-year (%)

2.7 (1.6–4.8)

1.4 (0.4–4.2)

4.2 (2.2–8.0)

0.0581

Distant brain failure

 Median time (months)

24.9 (18.4-n.r.)

24.9 (15.6-n.r.)

24.4 (14.1-n.r.)

–

 1-year (%)

36.5 (30.3–43.4)

35.5 (26.9–45.8)

37.5 (29.1–47.3)

–

 2-year (%)

48.4 (41.4–56.0)

48.2 (38.2–59.4)

48.9 (39.4–59.4)

–

 3-year (%)

56.2 (48.4–64.2)

52.5 (41.7–64.2)

59.8 (48.9–71.0)

0.3595

Disease free survival

 Median time (months)

7.3 (6.3–8.8)

7.8 (5.9–10.5)

6.9 (6.0–8.4)

–

 1-year (%)

31.0 (25.4–36.8)

32.1 (24.0–40.5)

29.2 (21.7–37.1)

–

 2-year (%)

17.6 (13.1–22.5)

18.3 (12.0–25.8)

16.9 (11.0–23.8)

–

 3-year (%)

14.3 (10.1–19.0)

14.0 (8.3–21.2)

14.4 (9.0–21.1)

0.5960

Overall survival

 Median time (months)

17.8 (15.6–22.8)

18.6 (15.0–25.9)

16.2 (13.3–23.0)

–

 1-year (%)

65.7 (59.5–71.2)

65.2 (56.0–73.0)

65.3 (56.3–72.8)

–

 2-year (%)

41.1 (34.9–47.1)

42.3 (33.3–51.1)

39.1 (30.7–47.4)

–

 3-year (%)

30.0 (24.2–36.0)

29.9 (21.3–38.9)

29.0 (21.4–37.1)

0.4087

Predictors influencing cumulative incidence local progression

 Target volume

p < 0.001

HR 1.1 [1.1–1.2]

p = 0.499

HR 1.1 [0.8–1.6]

p = 0.004

HR 1.1 [1.0–1.2]

–

Predictors influencing distant brain failure

 Number of lesions

p = 0.01

HR 1.3 [1.1–1.5]

p < 0.01

HR 1.5 [1.1–1.9]

0.42

HR 1.1 [0.8–1.5]

–

Predictors influencing disease free survival

 Patients age

p = 0.001

HR 1.02 [1.01–1.03]

p = 0.029

HR 1.02 [1.00–1.04]

p = 0.022

HR 1.02 [1.00–1.04]

–

 KPS

p = 0.001

HR 0.7 [0.5–0.8]

p = 0.003

HR 0.6 [0.4–0.8]

p = 0.058

HR 0.71 [0.5–1.0]

–

 RPA class

p = 0.003

HR 1.8 [1.2–2.7]

p = 0.007

HR 2.1 [1.2–3.6]

p = 0.154

HR 1.5 [0.9–2.7]

–

 Number of lesions

p = 0.017

HR 1.2 [1.0–1.3]

p = 0.089

1.2 [1.0–1.4]

p = 0.052

1.2 [1.0–1.5]

–

Predictors influencing overall survival

 Patients age

p < 0.001

HR 1.03 [1.01–1.04]

p = 0.030

HR 1.02 [1.00–1.05]

p = 0.002

HR 1.03 [1.01–1.05]

–

 KPS

p =  < 0.001

HR 0.5 [0.4–0.7]

p < 0.002

HR 0.6 [0.4–0.8]

p < 0.001

HR 0.5 [0.3–0.7]

–

 RPA class

p = 0.05

HR 1.8 [1.2–2.7]

p = 0.106

HR 1.6 [0.9–2.9]

p = 0.046

HR 2.0 [1.0–3.8]

–

 Number of lesions

p = 0.002

HR 1.3 [1.1–1.4]

p = 0.018

HR 1.3 [1.0–1.5]

p = 0.031

HR 1.3 [1.0–1.6]

–