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Table 4 Example of the global calculation results of the gamma evaluation and the index system for one of the head and neck cases applied spatial displacement along lateral direction

From: To propose adding index of achievement (IOA) to IMRT QA process

  Intentional Dose Error
−3% −2% −1% 0 + 1% + 2% + 3%
Intentional Spatial Error -3 mm Gamma pass rate (%) 4%/4 mm 92.7 100.0 100.0 100.0 100.0 100.0 92.6
3%/3 mm 69.9 81.5 88.6 100.0 89.2 82.6 69.5
2%/2 mm 45.7 55.4 63.5 66.1 62.7 53.0 43.5
1%/1 mm 13.3 17.4 22.2 23.3 20.2 15.9 12.1
IOA 1.060 1.056 1.052 1.051 1.052 1.055 1.059
IOH 1.022 1.025 1.029 1.034 1.039 1.045 1.052
IOC 0.936 0.942 0.948 0.953 0.958 0.962 0.966
-2 mm Gamma pass rate (%) 4%/4 mm 100.0 100.0 100.0 100.0 100.0 100.0 100.0
3%/3 mm 79.4 100.0 100.0 100.0 100.0 100.0 76.9
2%/2 mm 47.6 65.4 79.4 100.0 78.8 62.6 46.9
1%/1 mm 11.8 17.5 29.0 35.1 27.1 17.0 11.4
IOA 1.049 1.043 1.039 1.038 1.039 1.042 1.048
IOH 1.014 1.017 1.020 1.024 1.030 1.036 1.044
IOC 0.948 0.955 0.961 0.966 0.971 0.975 0.978
-1 mm Gamma pass rate (%) 4%/4 mm 100.0 100.0 100.0 100.0 100.0 100.0 100.0
3%/3 mm 94.6 100.0 100.0 100.0 100.0 100.0 92.9
2%/2 mm 47.6 81.4 100.0 100.0 100.0 79.1 47.0
1%/1 mm 8.2 16.1 40.7 100.0 37.2 16.0 7.4
IOA 1.036 1.029 1.023 1.020 1.022 1.028 1.036
IOH 1.005 1.007 1.009 1.013 1.019 1.026 1.035
IOC 0.962 0.970 0.976 0.982 0.986 0.989 0.992
0 Gamma pass rate (%) 4%/4 mm 100.0 100.0 100.0 100.0 100.0 100.0 100.0
3%/3 mm 100.0 100.0 100.0 100.0 100.0 100.0 100.0
2%/2 mm 55.3 100.0 100.0 100.0 100.0 100.0 55.8
1%/1 mm 0 0.1 100.0 100.0 100.0 0.1 0
IOA 1.030 1.020 1.010 1.000 1.010 1.020 1.030
IOH 1.000 1.000 1.000 1.000 1.010 1.020 1.030
IOC 0.970 0.980 0.990 1.000 1.000 1.000 1.000
+ 1 mm Gamma pass rate (%) 4%/4 mm 100.0 100.0 100.0 100.0 100.0 100.0 100.0
3%/3 mm 92.8 100.0 100.0 100.0 100.0 100.0 95.0
2%/2 mm 45.7 78.4 100.0 100.0 100.0 82.2 48.5
1%/1 mm 7.1 15.4 36.5 100.0 41.3 16.6 8.4
IOA 1.036 1.029 1.023 1.020 1.023 1.028 1.036
IOH 1.005 1.007 1.010 1.014 1.019 1.027 1.035
IOC 0.962 0.971 0.978 0.984 0.989 0.992 0.995
+ 2 mm Gamma pass rate (%) 4%/4 mm 100.0 100.0 100.0 100.0 100.0 100.0 100.0
3%/3 mm 75.6 100.0 100.0 100.0 100.0 100.0 81.6
2%/2 mm 44.3 60.7 78.5 100.0 79.9 67.0 49.9
1%/1 mm 10.6 16.3 26.3 35.1 29.8 18.2 12.5
IOA 1.049 1.043 1.039 1.038 1.039 1.042 1.048
IOH 1.015 1.018 1.022 1.026 1.031 1.037 1.045
IOC 0.950 0.958 0.964 0.970 0.976 0.980 0.984
+ 3 mm Gamma pass rate (%) 4%/4 mm 91.5 100.0 100.0 100.0 100.0 100.0 94.3
3%/3 mm 66.4 80.1 88.1 100.0 89.9 84.4 74.1
2%/2 mm 41.4 51.1 61.7 66.0 64.6 57.6 47.9
1%/1 mm 11.1 14.9 19.5 23.3 23.0 18.2 14.1
IOA 1.060 1.056 1.053 1.051 1.052 1.055 1.059
IOH 1.024 1.028 1.032 1.036 1.041 1.047 1.054
IOC 0.940 0.947 0.954 0.960 0.966 0.970 0.975