Table 1.
QA tests for image guidance system.
| Frequency | QA test | Tolerance |
|---|---|---|
| Daily | Safety checks | Functional |
| Imager positioning/repositioning | ±1 mm | |
| Imaging and treatment co-ordinate coincidence (single gantry angle) | ±1 mm | |
| Monthly | Imaging and treatment co-ordinate coincidence (4 cardinal gantry angles) | ±1 mm |
| Image scaling | ±2 mm | |
| Mechanical alignment – full range of travel | ±2 mm | |
| Geometric accuracy for CBCT | ±2 mm | |
| Automatic image registration and offset calculation accuracy | ±2 mm | |
| Image quality – planar and CBCT | Baseline ± 5% | |
| Annual | Imaging dose | Baseline ± 3% |