Table 5.

Percentage differences ^a in the total scatter factor (TSF), by institution and energy, between measured values and those calculated by analytical anisotropic algorithm for each test case

	TBCC		CCI
Test case	6 MV (%)	15 MV (%)	6 MV (%)	15 MV (%)
1. Open square fields	0.4	1.3	0.3	1.0
	—	—	0.6	0.6
	0.5	0.4	0.6	0.7
2. Extended source‐to‐surface distance	0.6	1.5	0.9	1.1
	0.5	0.5	0.5	0.3
3. Rectangular fields	0.3	0.8	0.6	0.9
	0.4	0.8	0.0	0.6
4a. Wedged fields	1.4	1.0	1.4	$-0.6$
	1.2	1.0	0.5	$-0.5$
	1.1	$-3.0$	0.5	$-0.6$
4b. Open collimator, 45 degrees	0.3	0.1	—	—
Wedged collimator, 45 degrees	1.1	1.1	1.0	$-0.5$
5. Mantle field	0.5	$-0.8$	0.9	1.3
6. Isocentric	0.0	$-0.6$	0.1	0.2
7. Oblique incidence	$-1.4$	$-0.6$	$-1.3$	0.4
	$-1.0$	$-0.9$	$-1.0$	1.0
8. Asymmetric fields	0.3	$-0.2$	—	—
	1.4	0.3	$-1.0$	$-2.3$
9. Oblique, wedged	$-0.7$	0.5	0.4	$-1.4$
10. Multileaf collimator shaped	0.7	1.5	0.7	1.2
Mean	0.4	0.3	0.3	0.2
Range	1.4	1.5	1.4	1.3
	$-1.4$	$-3.0$	$-1.3$	$-2.3$

^aDiscrepancies greater than 2% are bolded.