Table 2b.

Plan quality indices for Vestibular Schwannoma cases

Patient	Volume (cc)	GK Tx Time (min)	Prescription Isodose Line (%)		Conformity Index (CI)		Paddick Conformity Index (PCI)		Gradient Index (GI)
			Gamma Knife	VMAT	Gamma Knife	VMAT	Gamma Knife	VMAT	Gamma Knife	VMAT
1	4.43	47	50	62	1.30	1.27	0.76	0.79	2.58	2.89
2	5.26	47	60	56	1.27	1.26	0.78	0.78	3.19	2.71
3	0.47	44	50	55	1.36	1.49	0.72	0.67	2.94	4.01
4	5.39	58	50	57	1.23	1.20	0.80	0.83	2.77	2.69
5	0.37	16	80	73	1.95	2.08	0.51	0.48	8.03	5.08
6	0.21	19	76	65	1.29	1.57	0.77	0.63	4.30	4.42
7	0.72	37	52	50	1.35	1.74	0.74	0.57	2.71	3.10
8	1.11	54	56	62	1.41	1.77	0.70	0.56	3.13	3.65
Mean ± SD	2.25 ± 2.34	40 ± 15	59 ± 12	60 ± 7	1.39 ± 0.23	1.57 ± 0.28	0.72 ± 0.09	0.66 ± 0.13	3.71 ± 1.83	3.60 ±0.84
P		<0.05	> 0.05		> 0.05		> 0.05		> 0.05

Abbreviations: VMAT = Volumetric modulated arc therapy; SD = standard deviation; GK Tx = Gamma Knife Treatment; p =Wilcoxon signed rank test, comparison of Gamma Knife and VMAT, p < 0.05 considered to be statistically significant.