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Table 5 Example of the local 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 71.1 83.6 95.2 100.0 94.2 81.3 68.6
3%/3 mm 52.8 63.7 73.0 100.0 72.7 62.6 52.0
2%/2 mm 30.8 37.5 45.1 45.9 42.1 35.1 28.8
1%/1 mm 6.0 6.9 9.0 8.0 8.0 5.7 4.8
IOA 1.210 1.189 1.176 1.171 1.177 1.191 1.212
IOH 1.083 1.095 1.109 1.127 1.148 1.173 1.202
IOC 0.807 0.836 0.863 0.885 0.904 0.920 0.933
-2 mm Gamma pass rate (%) 4%/4 mm 79.5 90.9 98.2 100.0 98.0 89.1 76.5
3%/3 mm 56.2 72.9 90.8 100.0 89.4 70.3 54.5
2%/2 mm 30.8 41.9 56.6 100.0 54.3 41.3 30.3
1%/1 mm 4.9 6.8 11.1 12.3 10.0 6.5 4.8
IOA 1.175 1.148 1.130 1.124 1.131 1.149 1.176
IOH 1.052 1.062 1.075 1.091 1.112 1.139 1.170
IOC 0.833 0.865 0.893 0.916 0.933 0.946 0.957
-1 mm Gamma pass rate (%) 4%/4 mm 82.7 93.2 99.1 100.0 99.0 91.9 80.2
3%/3 mm 63.4 81.4 95.6 100.0 95.1 79.8 61.7
2%/2 mm 26.6 44.6 74.1 100.0 72.2 44.0 26.6
1%/1 mm 3.6 6.5 14.6 100.0 13.7 6.5 3.3
IOA 1.140 1.106 1.078 1.067 1.078 1.106 1.141
IOH 1.018 1.024 1.033 1.048 1.071 1.104 1.140
IOC 0.861 0.897 0.929 0.954 0.969 0.978 0.985
0 Gamma pass rate (%) 4%/4 mm 83.1 93.4 99.3 100.0 99.3 93.1 81.8
3%/3 mm 64.5 82.7 96.3 100.0 96.2 82.5 64.5
2%/2 mm 28.0 50.5 79.9 100.0 80.2 51.4 29.0
1%/1 mm 0 0 0.1 100.0 0.1 0 0
IOA 1.124 1.083 1.041 1.000 1.041 1.083 1.124
IOH 1.000 1.000 1.000 1.000 1.041 1.083 1.124
IOC 0.876 0.917 0.959 1.000 1.000 1.000 1.000
+ 1 mm Gamma pass rate (%) 4%/4 mm 81.7 92.4 99.1 100.0 99.1 93.1 81.8
3%/3 mm 61.7 80.1 95.1 100.0 95.5 81.5 63.4
2%/2 mm 24.9 42.8 72.1 100.0 74.0 45.5 28.1
1%/1 mm 3.1 6.1 13.3 100.0 14.9 6.8 3.9
IOA 1.140 1.106 1.078 1.067 1.079 1.107 1.141
IOH 1.018 1.025 1.034 1.049 1.072 1.105 1.141
IOC 0.861 0.897 0.930 0.954 0.969 0.978 0.985
+ 2 mm Gamma pass rate (%) 4%/4 mm 77.7 89.7 98.2 100.0 98.3 91.1 79.7
3%/3 mm 53.6 69.8 89.7 100.0 90.9 74.5 57.9
2%/2 mm 27.8 39.1 53.5 100.0 57.7 43.8 32.9
1%/1 mm 4.4 6.2 9.6 12.3 11.5 7.3 5.3
IOA 1.174 1.149 1.131 1.125 1.132 1.151 1.178
IOH 1.054 1.064 1.077 1.093 1.115 1.141 1.172
IOC 0.834 0.866 0.894 0.917 0.934 0.947 0.957
+ 3 mm Gamma pass rate (%) 4%/4 mm 67.8 81.0 94.6 100.0 95.7 84.6 73.5
3%/3 mm 50.1 60.1 71.6 100.0 75.0 67.3 55.8
2%/2 mm 27.5 34.1 41.6 46.5 45.7 38.8 32.1
1%/1 mm 4.4 5.3 7.7 8.0 9.4 7.3 6.4
IOA 1.211 1.191 1.178 1.174 1.179 1.194 1.216
IOH 1.087 1.099 1.114 1.131 1.152 1.177 1.205
IOC 0.808 0.837 0.864 0.886 0.905 0.921 0.934