Dosimetric characteristics of 6MV flattening filter free and flattened beams among beam-matched linacs: a three-institutional study

Table 2 Unflatness and symmetry for 6MV FFF beam measured at three different depth 5 cm, 10 cm and 20 cm. (reproduced with permission from MedEuropa)

Parameter	Field size (cm²)	Depth (mm)	Ref.	Measured data			Deviation from reference (%)
Parameter	Field size (cm²)	Depth (mm)	Ref.	Linac 1	Linac 2	Linac 3	Linac 1	Linac 2	Linac 3
Unflatness	3x3	50	1.035	1.043	1.038	1.038	0.77	0.24	0.29
	3x3	100	1.034	1.043	1.038	1.039	0.87	0.39	0.44
	3x3	200	1.033	1.044	1.039	1.040	1.11	0.58	0.73
	5x5	50	1.036	1.037	1.036	1.037	0.05	0.00	0.05
	5x5	100	1.039	1.041	1.038	1.039	0.19	0.10	0.0
	5x5	200	1.040	1.041	1.040	1.040	0.05	0.05	0.00
	10x10	50	1.134	1.134	1.132	1.135	0.00	-0.13	0.13
	10x10	100	1.148	1.148	1.147	1.150	0.00	-0.09	0.22
	10x10	200	1.159	1.157	1.158	1.159	-0.17	0.13	0.04
Symmetry	3x3	50	100.00	100.44	100.15	100.51	0.44	0.15	0.51
	3x3	100	100.00	100.33	100.20	100.43	0.33	0.20	0.43
	3x3	200	100.00	100.52	100.43	100.51	0.52	0.43	0.51
	5x5	50	100.00	100.21	100.23	100.28	0.21	0.23	0.28
	5x5	100	100.00	100.32	100.20	100.29	0.32	0.20	0.29
	5x5	200	100.00	100.29	100.25	100.22	0.29	0.25	0.22
	10x10	50	100.00	100.43	100.41	100.32	0.43	0.41	0.32
	10x10	100	100.00	100.67	100.38	100.37	0.67	0.38	0.37
	10x10	200	100.00	100.55	100.38	100.28	0.55	0.38	0.28

ISSN: 1748-717X