Table 1 Geometric checks: MPC and independent checks for all evaluated parameters, all energies
From: Evaluation of the Machine Performance Check application for TrueBeam Linac
Parameter | Check | Thresh | 6MV | 10MV | 15MV | 6MV FFF | 10MV FFF |
|---|---|---|---|---|---|---|---|
ISOCENTER | |||||||
Isocenter size [mm] | MPC | ±0.50 | 0.34 ± 0.01 | 0.31 ± 0.01 | 0.34 ± 0.01 | 0.42 ± 0.02 | 0.37 ± 0.02 |
Winston-Lutz [mm] | Indep | 0.264 | 0.271 | 0.257 | 0.289 | 0.278 | |
MV imager proj. offset [mm] | MPC | ±0.50 | 0.17 ± 0.03 | 0.17 ± 0.04 | 0.29 ± 0.03 | 0.43 ± 0.06 | 0.15 ± 0.04 |
MV imager proj. offset [mm] | Indep | 0.3 ± 0.2 | 0.3 ± 0.2 | 0.3 ± 0.2 | 0.3 ± 0.1 | 0.3 ± 0.1 | |
kV imager proj. offset [mm] | MPC | ±0.50 | 0.32 ± 0.02 | 0.33 ± 0.03 | 0.29 ± 0.03 | 0.29 ± 0.04 | 0.36 ± 0.03 |
kV imager proj. offset [mm] | Indep | 0.4 ± 0.1 | 0.4 ± 0.1 | 0.4 ± 0.1 | 0.3 ± 0.2 | 0.3 ± 0.2 | |
COLLIMATION | |||||||
MLC: Max Offset A [mm] | MPC | ±1.00 | −0.35 ± 0.03 | −0.40 ± 0.03 | −0.38 ± 0.02 | −0.26 ± 0.02 | −0.35 ± 0.02 |
MLC: Max Offset B [mm] | MPC | ±1.00 | 0.44 ± 0.02 | 0.56 ± 0.01 | 0.54 ± 0.01 | 0.34 ± 0.02 | 0.45 ± 0.02 |
MLC: Mean Offset A [mm] | MPC | ±1.00 | −0.24 ± 0.02 | −0.30 ± 0.02 | −0.27 ± 0.02 | −0.16 ± 0.02 | −0.25 ± 0.02 |
MLC: Mean Offset B [mm] | MPC | ±1.00 | 0.25 ± 0.02 | 0.36 ± 0.01 | 0.34 ± 0.01 | 0.15 ± 0.02 | 0.26 ± 0.01 |
MLC: Max Offset A [mm] | Indep | ±1.00 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 |
MLC: Max Offset B [mm] | Indep | ±1.00 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 | ≤0.5 ± 0.5 |
Jaws: Offset X1 [mm] | MPC | ±1.00 | 0.01 ± 0.01 | 0.04 ± 0.01 | 0.04 ± 0.01 | 0.04 ± 0.02 | 0.06 ± 0.01 |
Jaws: Offset X2 [mm] | MPC | ±1.00 | 0.06 ± 0.02 | 0.13 ± 0.02 | 0.11 ± 0.02 | 0.06 ± 0.03 | 0.16 ± 0.02 |
Jaws: Offset Y1 [mm] | MPC | ±2.00 | −1.02 ± 0.05 | −0.98 ± 0.01 | −0.98 ± 0.01 | −1.06 ± 0.03 | −1.00 ± 0.01 |
Jaws: Offset Y2 [mm] | MPC | ±2.00 | 0.87 ± 0.04 | 0.95 ± 0.03 | 0.90 ± 0.03 | 0.89 ± 0.03 | 0.98 ± 0.01 |
Jaws: Offset X1 [mm] | Indep | 0.6 ± 0.2 | 0.9 ± 0.2 | 0.8 ± 0.2 | 0.2 ± 0.3 | 0.5 ± 0.3 | |
Jaws: Offset X2 [mm] | Indep | 0.8 ± 0.2 | 0.9 ± 0.2 | 1.2 ± 0.2 | 1.0 ± 0.3 | 1.1 ± 0.3 | |
Jaws: Offset Y1 [mm] | Indep | −0.1 ± 0.2 | 0.3 ± 0.2 | 0.3 ± 0.2 | −0.6 ± 0.3 | 0.2 ± 0.2 | |
Jaws: Offset Y2 [mm] | Indep | −0.1 ± 0.3 | 0.1 ± 0.2 | 0.3 ± 0.2 | 0.1 ± 0.2 | −0.1 ± 0.2 | |
Collimator rotation offset [°] | MPC | ±0.50 | 0.17 ± 0.01 | 0.16 ± 0.01 | 0.16 ± 0.01 | 0.16 ± 0.01 | 0.16 ± 0.01 |
Collimator rotation offset [°] | Indep | −0.1 ± 0.1 | −0.1 ± 0.1 | −0.1 ± 0.1 | −0.1 ± 0.1 | −0.1 ± 0.1 | |
GANTRY | |||||||
Absolute [°] | MPC | ±0.30 | −0.09 ± 0.02 | −0.09 ± 0.02 | −0.10 ± 0.03 | −0.10 ± 0.01 | −0.09 ± 0.02 |
Relative [°] | MPC | ±0.30 | 0.08 ± 0.01 | 0.09 ± 0.01 | 0.09 ± 0.01 | 0.09 ± 0.01 | 0.09 ± 0.01 |
Relative [°] | Indep | 0.0 ± 0.1 | 0.0 ± 0.1 | 0.0 ± 0.1 | 0.0 ± 0.1 | 0.0 ± 0.1 | |
COUCH | |||||||
Lateral [mm] | MPC | ±0.70 | −0.06 ± 0.02 | −0.07 ± 0.02 | −0.05 ± 0.02 | −0.04 ± 0.02 | −0.07 ± 0.02 |
Longitudinal [mm] | MPC | ±0.70 | 0.14 ± 0.02 | 0.12 ± 0.01 | 0.14 ± 0.02 | 0.20 ± 0.04 | 0.13 ± 0.02 |
Vertical [mm] | MPC | ±1.20 | −0.34 ± 0.01 | −0.33 ± 0.02 | −0.32 ± 0.01 | −0.32 ± 0.02 | −0.33 ± 0.02 |
Rotation [°] | MPC | ±0.40 | 0.00 ± 0.01 | 0.00 ± 0.01 | 0.00 ± 0.01 | 0.01 ± 0.01 | 0.00 ± 0.01 |
Rotation-induced shift [mm] | MPC | ±0.75 | 0.37 ± 0.02 | 0.36 ± 0.01 | 0.35 ± 0.02 | 0.37 ± 0.02 | 0.38 ± 0.02 |
Lateral [mm] | Indep | 0.1 ± 0.2 | 0.1 ± 0.2 | 0.1 ± 0.2 | 0.1 ± 0.2 | 0.1 ± 0.2 | |
Longitudinal [mm] | Indep | 0.3 ± 0.4 | 0.3 ± 0.4 | 0.3 ± 0.4 | 0.3 ± 0.4 | 0.3 ± 0.4 | |
Vertical [mm] | Indep | −0.1 ± 0.3 | −0.1 ± 0.3 | −0.1 ± 0.3 | −0.1 ± 0.1 | −0.1 ± 0.1 | |
Rotation [°] | Indep | 0.0 ± 0.1 | 0.0 ± 0.1 | 0.0 ± 0.1 | 0.0 ± 0.1 | 0.0 ± 0.1 | |
Winston-Lutz [mm] | Indep | 0.803 | n/a | n/a | n/a | n/a |