Table 5.
Comparison between planned and delivered doses. Dose errors positive if planned dose exceeds measured dose. Positive values of Δx and Δy and Δz indicate, respectively, that radiation was delivered to the right (prone patient's left), superiorly, and anteriorly from CBCT isocenter. Three‐dimensional vector error v defined as v = (Δx 2 + Δy 2 + Δz 2)0.5
| MU | Average dose error (%) | Max dose error (%) | Average error Δx (mm) | Average error Δy (mm) | Average error Δz (mm) | Average vector error v (mm) | Maximum vector error v (mm) |
|---|---|---|---|---|---|---|---|
| 1592 | 1.2 ± 2.3 | 3.8 | −0.18 ± 0.14 | 0.04 ± 0.18 | −0.03 ± 0.10 | 0.3 ± 0.10 | 0.42 |