Table 4.

Independent sample t test of dose-volume parameters for PBM and its sub-regions between PBM sparing IMRT group and non-PBM sparing IMRT group $(\overline{x}\pm s)$.

Dose-volume parameters	PBM		P	Lumbosacral spine BM		P	Ilium BM		P	Lower pelvic BM		P
	PBM sparing IMRT (%)	non-PBM sparing IMRT (%)		PBM sparing IMRT (%)	non-PBM sparing IMRT (%)		PBM sparing IMRT (%)	non-PBM sparing IMRT (%)		PBM sparing IMRT (%)	non-PBM sparing IMRT (%)
V 5	92.5 ± 5.4	97.2 ± 3.3	<0.001	93.8 ± 8.7	87.4 ± 6.3	0.014	96.2 ± 5.9	98.3 ± 3.6	0.023	88.3 ± 10.6	96.4 ± 5.0	<0.001
V 10	82.1 ± 6.4	91.6 ± 5.6	<0.001	89.2 ± 11.2	95.0 ± 8.5	0.002	87.7 ± 8.1	92.4 ± 8.5	0.001	72.7 ± 14.1	89.2 ± 9.7	<0.001
V 15	72.6 ± 6.1	86.2 ± 7.3	<0.001	86.7 ± 11.9	93.3 ± 9.4	0.002	76.5 ± 8.6	85.7 ± 7.7	<0.001	60.3 ± 14.3	83.0 ± 12.5	<0.001
V 20	62.4 ± 5.7	78.1 ± 8.4	<0.001	83.5 ± 12.1	91.1 ± 10.4	0.001	61.6 ± 9.3	75.8 ± 9.4	<0.001	48.9 ± 13.6	72.8 ± 14.2	<0.001
V 25	51.4 ± 5.6	65.2 ± 7.9	<0.001	79.3 ± 12.0	87.4 ± 11.2	<0.001	46.1 ± 8.6	58.2 ± 10.0	<0.001	37.4 ± 12.0	58.3 ± 14.7	<0.001
V 30	40.8 ± 5.3	51.8 ± 8.0	<0.001	72.6 ± 11.6	79.9 ± 11.8	0.001	33.0 ± 7.2	41.1 ± 8.5	<0.001	26.3 ± 9.7	44.1 ± 14.9	<0.001
V 35	31.1 ± 5.3	38.1 ± 7.3	<0.001	61.5 ± 10.6	67.0 ± 11.5	0.010	22.6 ± 6.5	26.6 ± 7.3	0.003	18.0 ± 8.1	30.4 ± 12.3	<0.001
V 40	22.8 ± 4.6	26.8 ± 6.2	<0.001	49.3 ± 9.2	52.9 ± 11.1	0.059	14.6 ± 4.9	15.9 ± 5.0	0.169	12.2 ± 6.1	20.1 ± 9.1	<0.001
V 45	16.0 ± 3.8	18.0 ± 5.4	0.049	37.4 ± 8.0	38.5 ± 10.9	0.536	9.4 ± 3.5	9.7 ± 3.9	0.631	7.9 ± 4.4	12.3 ± 6.6	<0.001
V 50	8.9 ± 3.0	8.9 ± 5.0	0.930	21.6 ± 6.5	20.7 ± 11.7	0.604	4.5 ± 2.3	4.4 ± 3.0	0.778	3.6 ± 2.9	5.3 ± 4.4	0.027
Dmean	2635 ± 212	3057 ± 271	<0.001	3682 ± 575	3867 ± 430	0.060	2494 ± 263	2790 ± 267	<0.001	2126 ± 423	2817 ± 523	<0.001