Table 5: Average absolute volume (± 1σ) of normal tissue irradiated to at least 100% of the prescribed dose, V_NormPI.

Group	m3 (cm^3)	MLC-160 (cm^3)	Δ( MLC_160 - m3) (cm^3)		p-value
I	0.12 ± 0.06	0.16 ± 0.07	0.04	13.24 ± 7.93	< 0.001
II	1.15 ± 0.83	1.35 ± 0.95	0.20	5.89 ± 4.76	0.001
III	1.53 ± 1.12	1.90 ± 1.57	0.37	9.29 ± 12.28	0.004
IV	2.02 ± 1.72	2.85 ± 2.79	0.83	20.18 ± 16.93	< 0.001