Table 2.
Residual errors (mm) of a rigid target and different bony landmarks relevant for the target after the online match. The van Herk margins (3D) are given in the parenthesis (n = 40).
| Structure | Systematic error Σ (1 SD) |
Random error σ (1 SD) |
||||
|---|---|---|---|---|---|---|
| AP/vertical | SI/longitudinal | LAT/lateral | AP/vertical | SI/longitudinal | LAT/lateral | |
| Rigid targeta | 0.7 (2.5) | 0.6 (2.4) | 0.8 (2.8) | 1.2 | 1.3 | 1.1 |
| Observer error | 0.6 (2.2) | 0.7 (2.6) | 0.8 (2.8) | 1.1 | 1.2 | 1.2 |
| C1–2b | 1.1 (3.7) | 0.5 (2.0) | 1.1 (3.6) | 1.2 | 1.0 | 1.2 |
| C5–7b | 0.9 (3.1) | 0.6 (2.3) | 1.3 (4.2) | 1.2 | 1.2 | 1.4 |
| Mandibleb | 2.0 (6.4) | 2.0 (6.3) | 1.5 (4.7) | 1.9 | 1.9 | 1.5 |
| Occiput boneb | 1.4 (4.4) | 1.2 (4.0) | – | 1.6 | 1.5 | – |
a
For weekly IGRT including inter-observer variation.
b
For daily IGRT including inter-observer variation.