Table 2.

Results of bivariate and multivariate analyses for local tumor progression after stereotactic radiosurgery

	Bivariate		Multivariate
	HR [95% CI]	p-value	HR [95% CI]	p-value
Age, years (continuous)	1.02 [0.97–1.08]	0.422	–	–
Age > 70 years (vs. ≤ 70 years)	1.00 [0.33–3.02]	0.994	–	–
Male (vs. female)	0.49 [0.15–1.64]	0.249	0.37 [0.11–1.31]	0.123
Convexity, midline (vs. skull base)	0.77 [0.26–2.29]	0.634	–	–
Maximum diameter, mm (continuous)	1.02 [0.98–1.08]	0.270	–	–
Maximum diameter > 35 mm (vs. ≤ 35 mm)	1.44 [0.48–4.33]	0.521	–	–
Volume, mL (continuous)	1.06 [0.99–1.13]	0.095	1.08 [1.01–1.16]	0.023*
Volume > 8 mL (vs. ≤ 8 mL)	0.95 [0.32–2.86]	0.934	–	–
Ki-67 LI, % (continuous)	1.04 [0.97–1.10]	0.196	–	–
High LI (vs. low LI)	NA	NA	NA	NA
High LI (vs. intermediate LI)	3.75 [1.13–12.49]	0.031*	6.10 [1.56–23.95]	0.010*
History of radiation therapy	1.34 [0.43–4.13]	0.611	–	–
Salvage SRS (vs. adjuvant SRS)	0.61 [0.17–2.24]	0.460	–	–
Central dose, Gy (continuous)	1.0 [0.90–1.13]	0.932	–	–
Central dose > 36 Gy (vs. ≤ 36 Gy)	0.99[0.32–3.05]	0.984	–	–
Marginal dose, Gy (continuous)	0.95 [0.72–1.25]	0.736	–	–
Marginal dose > 18 Gy (vs. ≤ 18 Gy)	1.00 [0.33–3.03]	0.998	–	–

CI confidence interval, HR hazard ratio, LI labeling index, NA not adequately calculated, SRS stereotactic radiosurgery

*p-values of < 0.05 are considered significant;