Table 5.

Multivariate analysis of the risk factors of HI with different margin definition

Variables	The expanded margin of peri-hippocampus
	5 mm	10 mm	20 mm
	OR (95% CI)	p	OR (95% CI)	p	OR (95% CI)	p
Age
≥60 vs <60	0.71 (0.14–3.48)	0.67	0.98 (0.30–3.21)	0.97	1.04 (0.39–2.80)	0.94
BM status
Synchronous vs metachronous	0.33 (0.04–2.97)	0.32	0.30 (0.06–1.46)		0.53 (0.20–1.45)	0.22
Number of BM
>5 vs 1-5	2.55 (0.52–12.40)	0.25	3.84 (1.15–12.76)	0.03	3.60 (1.29–10.05)	0.01
>6 vs 1–6	5.20 (1.048–25.75)	0.04	5.38 (1.54–18.86)	0.01	3.84 (1.28–11.50)	0.02

BM, brain metastase.