Table 3 Patient specific IMRT QA absolute dose measurement analysis
Meas. num (n) | Percent difference between the mean and plan dose (%, 1 to n) | Probability for the mean to be within 3% of plan value (1 to n) | Probability for the mean to be within 5% of plan value (1 to n) |
|---|---|---|---|
a. Chamber 1: corresponding plan dose was 1.702 Gy. No QA phantom re-setup between each measurement. | |||
1 | 0.232 | - | - |
2 | -0.095 | 93.05% | 95.81% |
3 | -0.205 | 99.49% | 99.84% |
4 | -0.341 | 99.93% | 99.97% |
5 | -0.423 | 99.98% | 99.98% |
b. Chamber 2: corresponding plan dose was 0.546 Gy. No QA phantom re-setup between each measurement. | |||
1 | -5.960 | - | - |
2 | -6.551 | 3.28% | 9.96% |
3 | -6.939 | 0.70% | 3.12% |
4 | -7.132 | 0.10% | 0.70% |
5 | -7.319 | 0.02% | 0.17% |
c. Chamber 1: corresponding plan dose was 1.702 Gy. The QA phantom was re-setup between each measurement. | |||
1 | -0.751 | - | - |
2 | -0.259 | 89.57% | 93.72% |
3 | -3.153 | 39.74% | 65.16% |
4 | -2.388 | 55.53% | 81.86% |
5 | -2.193 | 65.01% | 90.52% |
d. Chamber 2: corresponding plan dose was 0.546 Gy. The QA phantom was re-setup between each measurement. | |||
1 | -8.065 | - | - |
2 | -11.327 | 4.76% | 8.88% |
3 | -12.963 | 1.69% | 3.35% |
4 | -13.432 | 0.39% | 0.85% |
5 | -14.164 | 0.07% | 0.18% |