Table 3.
Quality control tests for kilovoltage radiotherapy units (tolerances and action levels are specified in millimeters unless otherwise stated)
| Designator | Test | Performance | |
|---|---|---|---|
| Tolerance | Action | ||
| Daily | |||
| DK1 | Patient monitoring audiovisual devices | Functional | |
| DK2 | Door closing mechanism and interlock | Functional | |
| DK3 | Couch movement and brakes | Functional | |
| DK4 | Unit motions and motion stops | Functional | |
| DK5 | Interlocks for added filters/kV‐filter choice | Functional | |
| DK6 | Beam status indicators | Functional | |
| DK7 | Beam‐off at key‐off test | Functional | |
| DK8 | Emergency off test | Functional | |
| DK9 | kV and mA indicators | Functional | |
| DK10 | Backup timer/monitor unit channel check | 1% | 2% |
| DK11 | Dosimetric test: output check | 3% | 5% |
| Monthly | |||
| MK1 | Mechanical stability and safety | Functional | |
| MK2 | Cone selection and competency | Functional | |
| MK3 | Physical distance indicators | 2 | 3 |
| MK4 | Accuracy of head tilt and rotation readouts | 1° | 1.5° |
| MK5 | Light/x‐ray field coincidence | 2 | 3 |
| MK6 | Light field size | 2 | 3 |
| MK7 | X‐ray field size indicator | 2 | 3 |
| MK8 | X‐ray field uniformity/filter integrity | 5% | 8% |
| MK9 | Timer and end effect error | Characterize | min |
| MK10 | Output linearity | 1% | |
| MK11 | Output reproducibility | Characterize | <.03 CoV |
| MK12 | Beam quality | 10% | 15% |
| MK13 | Output calibration verification | 2% | 3% |
| MK14 | Timer accuracy verification | 2% | 3% |
| MK15 | Records | Complete | |
| Annually | |||
| AK1 | Reference dosimetry | 1% | 2% |
| AK2 | Alignment of focal spots | 0.5 | 1 |
| AK3 | kVp measurement | 5% | 10% |
| AK4 | Focal spot size | Reproducible | |
| AK5 | Independent quality control review | Complete | |