Table 2.
Patient set-up shifts compared against dose constraint failures: absolute setup displacement was compared against the degree of dose constraint pass or failures. Pearson correlation coefficients are reported for each ATP planning modality for the two most frequently failing targets (PTV 54.00 Gy, D95% and D98%). Direct isocentre shift distances were calculated from setup shifts in 3 coordinates using Pythagoras theory methods. The greatest shifts occurred in the superior-inferior direction.* p-value < 0.05 in all cases. AS – Adapt Segments; OW – Optimise Weights; OS – Optimise Shapes.
| Dose Constraint | ATP Variant | |||
|---|---|---|---|---|
| Patient 1 | Patient 2 | |||
| PTV 54 Gy | D95% >51.30 Gy | AS | *0.35 (-0.07–0.67) | *0.4 (0.05–0.67) |
| OW | *0.54 (0.17–0.78) | *0.57 (0.26–0.77) | ||
| OS | *0.52 (0.14–0.77) | *0.41 (0.06–0.67) | ||
| D98% >50.22 Gy | AS | *0.46 (0.05–0.73) | *0.48 (0.15–0.72) | |
| OW | *0.57 (0.21–0.80) | *0.58 (0.28–0.78) | ||
| OS | *0.56 (0.2–0.79) | *0.44 (0.09–0.69) | ||
| Mean setup shift (SD, mm) | ||||
| Right-Left | -1.63 (1.94) | 1.18 (1.56) | ||
| Anterior-Posterior | -1.78 (1.44) | -0.20 (1.43) | ||
| Superior-Inferior | 3.29 (1.95) | 3.31 (1.87) | ||