Table 3.

Cox proportional hazards analysis of clinical and treatment parameters associated with survival. Average KPS across treatments and pretreatment Neutrophil to Lymphocyte Ratio (NTLR) was the only variable associated with survival in both univariate and multivariate models.

Variable	UV Model HR	p value	MV Model HR	p value
Age	0.959 (0.917 to 1)	0.0629	0.952 (0.896 to 1.01)	0.104
Male sex	1.49 (0.657 to 3.37)	0.341
Number of SBRT treatments	1.04 (0.964 to 1.13)	0.3
Mean treatment BED	0.987 (0.976 to 0.998)	0.017	0.99 (0.978 to 1)	0.106
Mean KPS	0.911 (0.868 to 0.957)	0.00018	0.912 (0.864 to 0.963)	0.00083
Mean pretreatment neutrophil count	1.24 (1.06 to 1.45)	0.006
Mean pretreatment lymphocyte count	0.637 (0.312 to 1.3)	0.216
Mean pretreatment NTLR	1.11 (1.04 to 1.19)	0.003	1.14 (1.05 to 1.24)	0.0023
Received concurrent therapy	1.87 (0.742 to 4.69)	0.185

NLTR Neutrophil-to-lymphocyte ratio; SBRT stereotactic body radiotherapy; BED biologic equivalent dose; KPS Karnofsky performance status.