Table 3.
Variations in the target volume on CT dataset for the static and moving targets with regular breathing motion (static, 10‐phase, AIP and MIP CT datasets).
| Target ball volume (VT, cm3) | 4.19 | |
|---|---|---|
| CT type | GTVstatic (cm3) | Variation (GTVstatic/VT) |
| Static CT | 4.10 | −2.1% |
| 4D CT Phase | GTVphase (cm3) | Variation (GTVphase/VT) |
|---|---|---|
| 0% | 4.20 | 0.3% |
| 10% | 3.90 | −6.9% |
| 20% | 4.20 | 0.3% |
| 30% | 4.10 | −2.1% |
| 40% | 4.10 | −2.1% |
| 50% | 4.20 | 0.3% |
| 60% | 4.00 | −4.5% |
| 70% | 4.00 | −4.5% |
| 80% | 4.20 | 0.3% |
| 90% | 4.20 | 0.3% |
| Regular motion target volume (ITVth, cm3) | 13.61 | |
|---|---|---|
| 4D CT image type | ITV (cm3) | Variation (ITV/ITVth) |
| AIP | 12.7 | −6.7% |
| MIP | 13.1 | −3.8% |
AIP, average intensity projection; GTV, gross tumor volumes; ITV, internal target volumes; MIP, maximum intensity projection.