Table 2 Uni- and multivariate analysis

Freedom from local progression

BED 35.7 Gy10

0.13

HR 0.455 (95%CI 0.140–1.479); p = 0.19

GTV volume ≤ 0.4

0.041

HR 3.77 (95%CI 0.945–15.061); p = 0.06

PTV margin

0.59

–

BM site

(base = midbrain)

0.09

Pons: HR 0.202 (95%CI 0.048–0.845); p = 0.02

M. Oblongata: HR 0.627 (95%CI 0.150–2.619); p = 0.52

Primary histology

0.74

–

Previous WBRT

0.85

–

Concurrent targeted therapy

0.03

HR 0.169 (95%CI 0.021–1.348); p = 0.09

Single- versus multifraction

0.51

–

Overall survival

BED 35.7 Gy10

0.06

HR 0.887 (95%CI 0.534–1.473); p = 0.64

GTV volume ≤ 0.4

0.45

–

PTV margin

0.17

–

Primary histology

0.17

BM site

0.16

–

Previous WBRT

0.01

HR 1.59 (95%CI 0.827–3.080); p = 0.16

Concurrent targeted therapy

0.01

HR 0.466 (95%CI 0.270–0.804); p = 0.006

Single-versus multifraction

0.03

HR 1.61 (95%CI 0.972–2.696); p = 0.06

Cancer-specific survival

BED 35.7 Gy10

0.26

–

GTV volume ≤ 0.4

0.33

–

PTV margin

0.23

–

BM site

(base = midbrain)

0.06

Pons: HR 0.587 (95%CI 0.338–1.019); p = 0.06

M. oblongata: HR 1.026 (95%CI 0.505–2.082); p = 0.94

Primary histology

0.23

Previous WBRT

0.03

HR 2.055 (95%CI 1.023–4.128); p = 0.04

Concurrent targeted therapy

0.03

HR 0.573 (95%CI 0.331–0.992); p = 0.04

Single- versus multifraction

0.11

–

Neurological Death

BED 35.7 Gy10

0.75

–

GTV volume ≤ 0.4

0.75

–

PTV margin

0.54

–

Primary histology

0.23

BM site

(base = midbrain)

0.15

Pons: HR 0.431 (95%CI 0.179–1.037); p = 0.06

M. Oblongata: HR 0.631 (95%CI 0.172–2.308); p = 0.48

Previous WBRT

0.00

HR 3.381 (95%CI 1.287–8.879); p = 0.01

Concurrent targeted therapy

0.13

0.530 (95%CI 0.197–1.427); p = 0.21

Single- versus multifraction

0.74

–