Table 1.
Edge-to-edge distances between resolution cavities in CBCT scans and estimated width and length of the imaging phantom. Results are presented as deviation from the true values, 3 mm between air cavities, 14 mm between corner air cavities, 25.4 mm phantom diameter and 80 mm phantom length.
| Dates of QA check |
Deviation in distances between air cavities in transverse/sagittal slices (mm) |
Deviation in distances between corner air cavities (mm) |
Deviation in phantom representation (mm) |
||||
|---|---|---|---|---|---|---|---|
|
| |||||||
| 1mm→ 2mm |
2mm→ 3mm |
3mm→ 4mm |
Horizontal | Vertica l |
Diameter | Lengt h |
|
|
|
|||||||
| January 6 | 0/+0.3 | +0.6/+0.6 | +0.3/+0.3 | −0.5 | 0 | −0.1 | −0.2 |
| January 7 | +0.3/0 | 0/+0.3 | +0.3/+0.3 | −0.8 | −0.2 | −0.4 | −0.2 |
| January 9 | 0/0 | +0.3/+0.3 | +0.3/+0.3 | −0.8 | +0.3 | +1.1 | −0.5 |
| January 10 | 0/+0.3 | +0.6/+0.3 | +0.3/+0.6 | −0.8 | +0.3 | +0.2 | −0.2 |
| January 16 | +0.3/+0.6 | +0.3/+0.6 | +0.6/+0.3 | −0.8 | +0.3 | −0.1 | −1.1 |
| Isocenter re-alignment and system re-calibration on January 23 | |||||||
| January 29 | 0/0 | +0.3/+0.3 | +0.3/+0.3 | −0.2 | +0.3 | +1.0 | +0.3 |
| February 7 | 0/+0.3 | +0.3/+0.6 | +0.6/+0.3 | −0.2 | +0.3 | +1.0 | 0 |
| February 14 | +0.6/+0.3 | +0.3/+0.6 | +0.3/+0.3 | −0.5 | 0 | +1.0 | +0.6 |
| March 3 | 0/0 | +0.3/+0.3 | +0.3/+0.3 | −0.2 | +0.3 | +0.2 | 0 |
| March 18 | 0/+0.3 | +0.3/+0.3 | +0.3/+0.6 | −0.2 | 0 | +0.7 | +0.3 |
| April 25 | 0/+0.3 | +0.3/+0.3 | +0.3/+0.3 | −0.2 | 0 | +0.2 | +0.3 |
| April 3 | 0/+0.3 | +0.3/+0.3 | 0/+0.3 | −0.2 | −0.2 | −0.1 | 0 |
| May 5 | 0/+0.3 | +0.3/+0.3 | +0.3/+0.3 | −0.2 | +0.3 | +0.5 | 0 |
| May 15 | 0/0 | 0/+0.3 | 0/+0.3 | −0.2 | +0.3 | −0.1 | +0.3 |
| May 29 | 0/+0.3 | +0.3/+0.3 | +0.3/+0.3 | −0.5 | +0.3 | +0.2 | +0.3 |