Table 3.

Repeatability of position detection by ExacTrac (N = 14)

	mean ± SD	range	95% (abs.)	50% (abs.)
Difference before – after
lateral	–0.08 ± 0.52	–0.94 to +0.53	<0.8	<0.5
longitudinal	–0.05 ± 0.70	–0.74 to +1.01	<0.8	<0.1
vertical	–0.03 ± 0.42	–0.67 to +0.83	<0.7	<0.3
radial	0.73 ± 0.32	0.26 to 1.28	<1.2	<0.7

All units are in mm