Table 2.

Extracranial dose in percentage of SRS prescription dose from literature and current series. Numbers in italics are from actual reported distances, numbers in plain text are interpolated from anatomical location to allow comparison between the data

Craniocaudal distance from target (cm)	GKP (this study)	GKP (Lindquist) [18]	Novalis (Gevaert) [13]	Linac mMLC (Di Betta) [9]	Linac Cones (Di Betta) [9]	Cyberknife (Vlachopoulou) [29]	Cyberknife (Di Betta) [9]
Data from:	20 patients	1 humanoid phantom	40 patients	1 humanoid phantom	1 humanoid phantom	21 patients	1 humanoid phantom
15.5				0.9	1.26		0.418
18.0	0.044	0.077	0.331			2.1
30.5		0.035		0.20	0.36		0.182
34.0			0.189			0.65
43.0	0.010	0.013		0.092	0.174		0.154
53.0		0.0060		0.06	0.116		0.166
58.5						0.59
70.0	0.002	0.0027	0.025
75.5				0.026	0.052	0.47	0.116
80.5				0.022	0.044		0.116