Table 2. Mean dose–volume indices for non-coplanar intensity-modulated radiation therapy, partially wide tangents and a five-field plan.

	IMRT (%)	Partially wide tangents (%)	p-value (compared with IMRT plan)	Five-field (%)	p-value (compared with IMRT plan)
V95% of PTV	94.2	91.4	0.042	87.7	0.012
V95% of S/C	99.0	88.0	0.061	91.0	0.117
V95% of AX level I	99.8	96.9	0.063	85.4	0.111
V95% of AX level II	99.9	92.5	0.034	67.0	0.004
V95% of AX level III	99.8	85.6	0.002	65.0	0.015
V95% of IM nodes	98.0	99.6	0.045	81.8	0.036
V110% of PTV	3.6	16.8	0.038	51.8	0.001
V110% of S/Clav	0.5	24.5	0.041	33.8	0.003
V110% of AX level I	1.3	15.8	0.084	23.6	0.030
V110% of AX level II	0.4	11.6	0.088	26.8	0.008
V110% of AX level III	0.6	12.9	0.040	36.5	0.006
V110% of IM nodes	0.8	42.9	0.010	52.6	0.001
V20Gy left lung	29.8	38.4	0.016	23.1	0.047
V30Gy heart	2.3	7.5	0.010	4.9	0.020
V110% brachial plexus	0	5.7	0.070	18.8	0.010

V95%, the volume of target regions receiving 95% of the dose. V110%, the volume of target regions receiving 110% of the dose. V20Gy, the fraction volume receiving 20 Gy. V30Gy, the fraction volume receiving 30 Gy. AX, axillary; IM, internal mammary; IMRT, intensity-modulated radiation therapy; PTV, planning target volume; S/Clav, supraclavicular fossa.