Table 3.

Mean normal brain V25%[cc] for the ten cases planned using each combination of number of arcs, low dose constraint, jaw tracking, and collimator angle selection. The median difference with the combination having the smallest mean normal brain V25%[cc], the range of the differences, and the p-value for a one-sided Wilcoxon signed rank test are also shown.

Number of arcs	Low dose constraint	Jaw tracking	Collimator angle selected	Mean	Median difference	Range	p
4	+	+	+	244	0	-	-
4	+	-	+	252	5	2 to 19	0.00
4	+	+	-	258	11	-11 to 44	0.03
4	+	-	-	263	15	-6 to 66	0.01
2	+	+	+	279	30	0 to 76	0.00
2	+	-	+	283	37	-9 to 84	0.00
2	+	+	-	291	42	15 to 88	0.00
2	+	-	-	303	56	18 to 104	0.00
4	-	+	+	377	71	18 to 517	0.00
2	-	+	+	381	98	24 to 464	0.00
4	-	-	+	384	86	24 to 534	0.00
2	-	-	+	393	103	36 to 464	0.00
4	-	+	-	421	109	38 to 561	0.00
2	-	+	-	427	120	39 to 451	0.00
4	-	-	-	441	144	50 to 541	0.00
2	-	-	-	441	136	59 to 478	0.00