TABLE III.

15 MV Varian collected reference data. Median values are given with the standard deviation in parentheses. N is the number of measurements.

Parameter/Class		Base class	TB-flat
	N	100	14
PDD	5 cm	0.943 (0.003)	0.946 (0.002)
	10 cm	0.767 (0.003)	0.769 (0.001)
	15 cm	0.617 (0.003)	0.620 (0.001)
	20 cm	0.496 (0.002)	0.499 (0.001)
	N	97	14
Output factors	6 × 6 cm2	0.959 (0.005)	0.953 (0.003)
	15 × 15 cm2	1.030 (0.004)	1.035 (0.002)
	20 × 20 cm2	1.050 (0.006)	1.060 (0.003)
	30 × 30 cm2	1.075 (0.007)	1.085 (0.005)
	N	100	13
Off-axis factors	5 cm left	1.038 (0.008)	1.036 (0.004)
	10 cm avg	1.049 (0.008)	1.045 (0.004)
	15 cm left	1.061 (0.010)	1.056 (0.004)
	N	18	13
IMRT output factors	2 × 2 cm2	0.831 (0.006)	0.815 (0.006)
	3 × 3 cm2	0.893 (0.008)	0.885 (0.004)
	4 × 4 cm2	0.929 (0.008)	0.924 (0.002)
	6 × 6 cm2	0.965 (0.007)	0.964 (0.002)
	N	7	7
SBRT output factors	2 × 2 cm2	0.799 (0.004)	0.784 (0.006)
	3 × 3 cm2	0.865 (0.002)	0.855 (0.004)
	4 × 4 cm2	0.902 (0.003)	0.892 (0.004)
	6 × 6 cm2	0.949 (0.003)	0.938 (0.003)
	N	27	11
EDW factors	45°	0.814 (0.003)	0.811 (0.002)
	60°	0.716 (0.003)	0.713 (0.003)
	45° (15 × 15,15)	0.720 (0.001)	0.718 (0.003)
	N	44
Upper wedge factors	45°	0.523 (0.003)	N/A
	60°	0.434 (0.003)
	45° (15 × 15,15)	0.529 (0.003)