Prescribed dose error (%)

Gamma passing rate (%)

H & N

Prostate

Increasing

2.0

98.1 ± 0.3

98.8 ± 1.0

4.0

96.0 ± 1.2

91.1 ± 6.0

6.0

89.3 ± 2.9

82.8 ± 8.1

Decreasing

−2.0

95.4 ± 4.2

95.4 ± 4.9

−4.0

88.9 ± 8.7

85.3 ± 8.0

−6.0

80.3 ± 12.2

75.9 ± 5.3