Table 4. D_max, D_mean and D_min of various OARs in IMRT plans with and without HPC sparing.

ORA	Parameter	Non-sparing (Gy)	Sparing (Gy)	P-value
Lenses	Dmax	6.56±0.88	6.49±0.74	0.48
	Dmean	4.63±0.74	4.64±0.72	0.35
	Dmin	3.55±0.67	3.58±0.64	0.65
Eyes	Dmax	36.38±3.67	33.75±4.23	0.03
	Dmean	7.21±0.84	6.85±0.83	0.00
	Dmin	1.90±0.23	1.91±0.24	0.60
Temporal lobes	Dmax	67.83±2.36	67.69±2.43	0.48
	Dmean	20.74±4.06	19.95±3.97	0.01
	Dmin	1.55±0.38	1.51±0.38	0.04
Brain-stem	Dmax	53.06±0.40	53.00±0.44	0.18
	Dmean	35.59±0.84	35.66±0.85	0.09
	Dmin	9.19±0.30	9.23±0.30	0.44
Optic Nerves	Dmax	47.25±1.80	46.60±1.81	0.08
	Dmean	24.03±4.00	24.29±3.97	0.04
	Dmin	6.51±0.85	6.76±0.93	0.03
Optic Chiasm	Dmax	48.15±1.56	46.63±1.59	0.00
	Dmean	23.61±1.22	21.09±1.09	0.00
	Dmin	9.56±2.75	8.58±2.58	0.00
Cochleae	Dmax	58.54±3.62	58.19±3.60	0.06
	Dmean	42.89±1.53	43.39±1.72	0.01
	Dmin	32.88±2.35	32.94±2.19	0.73
Spinal Cord	Dmax	42.76±0.97	42.74±0.93	0.52
	Dmean	25.34±1.31	25.31±1.26	0.35
	Dmin	0.40±0.15	0.40±0.16	0.35

Data presented as mean±standard deviation. Two-tailed P values from paired t tests. Abbreviation: D_max =  maximum dose; D_mean =  mean dose; D_min =  minimum dose.