Table 2.
Summary of treatment parameters.
| Parameters | Mean | SD | Range |
|---|---|---|---|
| GTV volume (cm3) | 9.0 | 8.3 | 0.6–33.5 |
| ITV volume (cm3) | 11.6 | 9.9 | 1.2–38.1 |
| Marker motion amplitude (mm) | |||
| SI | 12.2 | 5.2 | 2.0–24.0 |
| LR | 1.5 | 1.0 | 0.0–4.4 |
| AP | 4.2 | 2.5 | 1.0–10.6 |
| Radial | 13.1 | 5.4 | 2.7–26.3 |
| Marker–GTV distance (mm) | |||
| SI | 4.9 | 5.7 | 0.0–25.2 |
| LR | 8.4 | 11.6 | 0.0–49.0 |
| AP | 8.9 | 11.5 | 0.0–41.4 |
| Radial | 15.6 | 15.2 | 0.0–55.4 |
| Marker–XST centre distance (cm) | |||
| SI | 0.5 | 0.6 | 0.0–2.2 |
| LR | 5.5 | 3.0 | 0.4–9.7 |
| AP | 6.2 | 3.6 | 0.5–12.0 |
| Radial | 9.3 | 1.8 | 5.3–12.4 |
| ITV margin (mm) | 4.1 | 2.3 | 0.5–9.1 |
| Marker migration (mm) | 1.5 | 0.7 | 0.2–3.3 |
| Treatment time per fraction (min) | 32.3 | 8.4 | 15–66 |
AP, anterior–posterior; GTV, gross tumour volume; ITV, internal target volume; LR, left–right; SD, standard deviation; SI, superior–inferior; XST, Xsight Spine Tracking.