Table 4.

The dose result of both intensity-modulated radiation therapy (IMRT) and SmartArc-based volumetric modulated arc therapy (VMAT-S) for ear (Gy)

Structure	Dose–volume index	IMRT (mean ± SD)	VMAT-S (mean ± SD)	p-value
Middle ear-L	Dmean	39.7 ± 5.7	32.9 ± 4.7	<0.001
	D2%	50.3 ± 5.7	47.8 ± 5.0	0.001
Middle ear-R	Dmean	41.3 ± 5.6	33.4 ± 5.0	<0.001
	D2%	50.7 ± 6.0	48.7 ± 5.9	0.001
Cochlea-L	Dmean	47.8 ± 4.0	43.8 ± 3.6	<0.001
	D2%	53.0 ± 3.9	49.9 ± 3.0	<0.001
Cochlea-R	Dmean	47.6 ± 5.4	42.7 ± 4.7	<0.001
	D2%	52.1 ± 4.6	48.6 ± 4.7	<0.001
Vestibule-L	Dmean	38.2 ± 5.1	35.2 ± 5.2	<0.001
	D2%	43.9 ± 5.1	41.2 ± 5.2	<0.001
Vestibule-R	Dmean	38.1 ± 5.3	34.9 ± 5.3	<0.001
	D2%	44.2 ± 5.1	40.3 ± 5.6	<0.001

D_2%, near maximum dose; D_mean, mean dose; L, left; R, right; SD, standard deviation.