Table 3.

Absolute and percentage (%) differences in volume (V.) between the original and rotated structures.

Structures	CTV	PTV	Brain Stem	Chiasm	Retina	Opt.N	Lens	Cochlea
Mean V.	$162.6\pm$	$232.5\pm$	$27.6\pm$	$0.6\pm$	$5.5\pm$	$1.0\pm$	$0.3\pm$	$0.08\pm$
$({\mathit{\text{cm}}}^3)$	85.4	103.8	3.4	0.4	0.9	0.5	0.2	0.03
Absolute Volume Difference $({\mathit{\text{cm}}}^3)$
$\pm 1°/1\hspace{0.17em}\text{mm}$	$0.4\pm \hspace{0.17em}0.5\pm$	$0.2\pm$	$0.01\pm$	$0.05\pm$	$0.02\pm$	$0.003\pm$	$0.0003\pm$
	0.5	0.8	0.3	0.06	0.02	0.06	0.009	0.006
$\pm 3°/1\hspace{0.17em}\text{mm}$	$0.6\pm$	$0.7\pm$	$0.2\pm$	$0.01\pm$	$0.08\pm$	$0.01\pm$	$0.009\pm$	$0.0004\pm$
	0.8	1.1	0.3	0.06	0.09	0.07	0.03	0.006
$\pm 5°/1\hspace{0.17em}\text{mm}$	$0.2\pm$	$0.7\pm$	$0.1\pm$	$0.01\pm$	$0.07\pm$	$0.02\pm$	$0.01\pm$	$0.0001\pm$
	1.0	1.1	0.4	0.05	0.02	0.07	0.03	0.008
$\pm 7°/1\hspace{0.17em}\text{mm}$	$0.3\pm$	$0.8\pm$	$0.3\pm$	$0.01\pm$	$0.08\pm$	$0.02\pm$	$0.01\pm$	$0.0004\pm$
	1.4	1.5	0.3	0.05	0.07	0.06	0.04	0.003
% differences	$~0.4\%$	$~0.4\%$	$~1.1\%$	$~1.7\%$	$~1.5\%$	$~2.0\%$	$~2.9\%$	$~4.9\%$

Mean V. = mean volume of the original structures.