Table 1:
Mean ± standard deviation for set-up and positioning errors in six axes across different head and neck subsites with calculated PTV margins for 90% and 95% confidence intervals. AP: Anterior/Poster; CC: Cranial/Caudal; LR: Left/Right; PTV: Planning Target Volume; GSH: Gordon and Siebers Hypofractionation formula; CVH: Classic van Herk formula
| AP (mm) | CC (mm) | LR (mm) | Yaw (°) | Roll (°) | Pitch (°) | 3D Vector | PTV (90% GSH) | PTV (95% GSH) | PTV (95% CVH) | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Interfractional Error | All | −0.2 ± 1.4 | 0.2 ± 1.8 | −0.1 ± 1.7 | 0 ± 1.1 | 0 ± 0.9 | −0.5 ± 0.9 | 2.5 ± 1.5 | 4.5 mm | 5.0 mm | 4.9 mm |
| Skull Base | −0.2 ± 1.2 | 0.2 ± 1.7 | −0.3 ± 1.4 | −0.1 ± 1.0 | 0 ± 0.7 | −0.4 ± .09 | 2.2 ± 1.3 | 4.5 mm | 5.0 mm | 4.9 mm | |
| Neck | −0.6 ± 1.7 | 0.3 ± 2.1 | 0 ± 1.6 | 0 ± 1.1 | 0.1 ± 1.0 | −0.7 ± 1.1 | 2.8 ± 1.4 | 5.2 mm | 5.8 mm | 5.7 mm | |
| Mucosal | −0.5 ± 1.7 | 0.1 ± 1.4 | 0.5 ± 2.0 | 0 ± 1.2 | −0.2 ± 0.8 | −0.3 ± 0.8 | 2.5 ± 1.7 | 5.1 mm | 5.6 mm | 5.6 mm | |
| Residual Error | All | 0.0 ± 0.3 | 0 ± 0.4 | 0 ± 0.3 | 0 ± 0.2 | 0 ± 0.3 | 0 ± 0.3 | 0.5 ± 0.5 | 1.0 mm | 1.1 mm | 0.8 mm |
| Skull Base | 0 ± 0.2 | 0 ± 0.3 | 0 ± 0.2 | 0 ± 0.2 | 0 ± 0.2 | 0 ± 0.2 | 0.4 ± 0.2 | 0.9 mm | 1.0 mm | 0.7 mm | |
| Neck | −0.1 ± 0.4 | 0 ± 0.4 | −0.1 ± 0.4 | 0 ± 0.3 | 0 ± 0.3 | −0.1 ± 0.4 | 0.6 ± 0.4 | 1.2 mm | 1.3 mm | 1.1 mm | |
| Mucosal | 0 ± 0.3 | 0 ± 0.3 | −0.1 ± 0.3 | 0 ± 0.2 | 0 ± 0.3 | 0 ± 0.3 | 0.5 ± 0.3 | 0.9 mm | 1.0 mm | 0.7 mm | |
| CBCT Positioning Agreement | All | −0.1 ± 0.6 | −0.1 ± 0.6 | 0.1 ± 0.4 | 0.1 ± 0.6 | 0 ± 0.5 | 0.1 ± 0.6 | 0.8 ± 0.6 | 1.6 mm | 1.7 mm | 1.5 mm |
| Skull Base | −0.1 ± 0.4 | −0.2 ± 0.5 | 0.1 ± 0.3 | 0.2 ± 0.4 | 0 ± 0.4 | 0.2 ± 0.4 | 0.6 ± 0.4 | 1.3 mm | 1.4 mm | 1.2 mm | |
| Neck | −0.2 ± 0.7 | −0.1 ± 0.7 | 0.2 ± 0.6 | 0 ± 0.8 | 0.0 ± 0.7 | 0.2 ± 0.8 | 1.0 ± 0.7 | 1.8 mm | 1.9 mm | 1.6 mm | |
| Mucosal | 0 ± 0.9 | −0.1 ± 0.9 | 0.2 ± 0.5 | 0 ± 0.7 | 0 ± 0.6 | 0 ± 0.9 | 1.1 ± 0.8 | 2.4 mm | 2.6 mm | 2.4 mm | |
| Intrafractional Error | All | 0.0 ± 0.7 | −0.1 ± 0.8 | 0 ± 0.5 | 0 ± 0.4 | 0 ± 0.5 | −0.1 ± 0.5 | 0.8 ± 0.5 | 1.5 mm | 1.6 mm | 1.4 mm |
| Skull Base | −0.1 ± 0.4 | −0.1 ± 0.5 | 0 ± 0.4 | 0 ± 0.4 | 0 ± 0.4 | −0.1 ± 0.4 | 0.6 ± 0.4 | 1.4 mm | 1.5 mm | 1.3 mm | |
| Neck | 0.0 ± 0.8 | −0.2 ± 0.7 | 0.0 ± 0.8 | −0.1 ± 0.5 | −0.1 ± 0.6 | −0.1 ± 0.6 | 1.1 ± 0.6 | 1.8 mm | 2.0 mm | 1.7 mm | |
| Mucosal | 0.1 ± 1.0 | 0.3 ± 1.4 | 0 ± 0.6 | 0.1 ± 0.4 | 0.1 ± 0.5 | 0.1 ± 0.6 | 0.9 ± 0.6 | 1.7 mm | 1.8 mm | 1.5 mm | |