Table 3.

Comparison of GK and CK plan parameters (26 lesions)

	GK	CK
	median (range)	median (range)	p value
Planned tumor volume (cm3)	2.50 (0.044‐1.99)	2.49 (0.053‐20.0)	0.94
Prescription dose (Gy)	18.0 (15.0‐22.0)		N/A
Prescription isodose %	45 (40‐50)	86 (77‐92)	< 0.00001
GTV coverage (%)	100 (96‐100)	98(96‐100)	0.99
Minimum dose (Gy)	18.2 (12.8‐26.7)	17.6 (13.0‐21.4)	0.40
Mean dose (Gy)	29.6 (19.9‐38.5)	20.6 (16.1‐25.8)	< 0.00001
Maximum dose (Gy)	40.3 (29.4‐51.0)	22.7 (16.5‐28.6)	< 0.00001
Homogeneity index (HI)	2.22 (2.00‐2.50)	1.18 (1.09‐1.30)	< 0.00001
$\text{GK}=\text{Gamma Knife}$, $\text{CK}=\text{CyberKnife}$, $\mathrm{N}/\mathrm{A}=\text{not applicable}$, $\text{GTV}=\text{gross tumor volume}$.