Table 2.

Difference in isocentric positioning based on automatic bony anatomy registration as compared with manual matching of implanted fiducials ^a

Displacement direction	Mean	Standard deviation	Min	Max	95% CI for mean
LR (ΔX)	$-0.18$	0.12	$-0.46$	0.04	0.05
SI (ΔY)	$-0.10$	0.31	$-0.42$	0.62	0.12
AP (ΔZ)	0.13	0.13	0.20	0.39	0.05
3D vector	0.41	0.10	0.25	0.67	0.04

^a $N=27$; all values in millimeters.

$\text{CI}=\text{confidence}$ interval; $\text{LR}=\text{left}—\text{right}$; $\text{SI}=\text{superior}—\text{inferior}$ $\text{AP}=\text{anterior}—\text{posterior}$; $3\mathrm{D}=\text{three}—\text{dimensional}$.