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
| Â | Intentional Dose Error | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
-3% | -2% | -1% | 0 | + 1% | + 2% | + 3% | ||||
Intentional Spatial Error | -3Â mm | Gamma pass rate (%) | 4%/4Â mm | 71.1 | 83.6 | 95.2 | 100.0 | 94.2 | 81.3 | 68.6 |
3%/3Â mm | 52.8 | 63.7 | 73.0 | 100.0 | 72.7 | 62.6 | 52.0 | |||
2%/2Â mm | 30.8 | 37.5 | 45.1 | 45.9 | 42.1 | 35.1 | 28.8 | |||
1%/1Â 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 | |||
-2Â mm | Gamma pass rate (%) | 4%/4Â mm | 79.5 | 90.9 | 98.2 | 100.0 | 98.0 | 89.1 | 76.5 | |
3%/3Â mm | 56.2 | 72.9 | 90.8 | 100.0 | 89.4 | 70.3 | 54.5 | |||
2%/2Â mm | 30.8 | 41.9 | 56.6 | 100.0 | 54.3 | 41.3 | 30.3 | |||
1%/1Â 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 | |||
-1Â mm | Gamma pass rate (%) | 4%/4Â mm | 82.7 | 93.2 | 99.1 | 100.0 | 99.0 | 91.9 | 80.2 | |
3%/3Â mm | 63.4 | 81.4 | 95.6 | 100.0 | 95.1 | 79.8 | 61.7 | |||
2%/2Â mm | 26.6 | 44.6 | 74.1 | 100.0 | 72.2 | 44.0 | 26.6 | |||
1%/1Â 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%/4Â mm | 83.1 | 93.4 | 99.3 | 100.0 | 99.3 | 93.1 | 81.8 | |
3%/3Â mm | 64.5 | 82.7 | 96.3 | 100.0 | 96.2 | 82.5 | 64.5 | |||
2%/2Â mm | 28.0 | 50.5 | 79.9 | 100.0 | 80.2 | 51.4 | 29.0 | |||
1%/1Â 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%/3Â mm | 61.7 | 80.1 | 95.1 | 100.0 | 95.5 | 81.5 | 63.4 | |||
2%/2Â mm | 24.9 | 42.8 | 72.1 | 100.0 | 74.0 | 45.5 | 28.1 | |||
1%/1Â 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%/3Â mm | 53.6 | 69.8 | 89.7 | 100.0 | 90.9 | 74.5 | 57.9 | |||
2%/2Â mm | 27.8 | 39.1 | 53.5 | 100.0 | 57.7 | 43.8 | 32.9 | |||
1%/1Â 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%/3Â mm | 50.1 | 60.1 | 71.6 | 100.0 | 75.0 | 67.3 | 55.8 | |||
2%/2Â mm | 27.5 | 34.1 | 41.6 | 46.5 | 45.7 | 38.8 | 32.1 | |||
1%/1Â 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 | |||