Table 6.

Gradient and conformity indices from six treatment plans

Plan/metric	Pre_IMRT	CRW_IMRT	RW_IMRT	Pre_VMAT	CRW_VMAT	RW_VMAT
Gradient measure (cm)	2.49 ± 0.37 (2.04–3.57)	2.39 ± 0.26 (2.11–2.89)	2.44 ± 0.23 (2.18–2.99)	1.65 ± 0.07 (1.52–1.76)	1.72 ± 0.08 (1.63–1.90)	1.66 ± 0.09 (1.52–1.84)
Conformity index	0.92 ± 0.05 (0.79–0.97)	0.91 ± 0.03 (0.86–0.97)	0.92 ± 0.03 (0.85–0.95)	0.90 ± 0.01 (0.88–0.91)	0.90 ± 0.01 (0.86–0.92)	0.92 ± 0.03 (0.86–0.99)

IMRT: intensity modulated radiotherapy; RW: rectal wall; VMAT: volumetric modulated arc therapy.