A Hybrid IMRT/VMAT Technique for the Treatment of Nasopharyngeal Cancer

Table 1

Dosimetric comparison of PTV for IMRT, VMAT, and Hybrid IMRT/VMAT plans.

	9F-IMRT	2ARC-VMAT	Hybrid	Pairwise comparison
				HI
PTV70	0.07 ± 0.03	0.08 ± 0.03	0.06 ± 0.03	0.32	0.89	0.05
PTV59.4	0.16 ± 0.04	0.20 ± 0.04	0.17 ± 0.04	0.00	0.92	0.01
PTV54	0.12 ± 0.02	0.14 ± 0.02	0.11 ± 0.02	0.04	0.00	0.00
CN
PTV70	0.47 ± 0.18	0.43 ± 0.12	0.62 ± 0.09	1.00	0.01	0.00
PTV59.4	0.58 ± 0.09	0.60 ± 0.10	0.64 ± 0.09	0.37	0.01	0.01
PTV54	0.63 ± 0.04	0.67 ± 0.05	0.69 ± 0.04	0.10	0.00	0.66

HI = homogeneity index; CN = conformation number.
: 9F-IMRT versus 2ARC-VMAT; : 9F-IMRT versus Hybrid; : 2ARC-VMAT versus Hybrid.