Table 1.
Comparison of dosimetric parameters for irradiation of portal vein thrombosis and target volumes and normal organs at risk (OARs) by using different treatment techniques.
| Coplanar IMRT | Noncoplanar IMRT | Tomotherapy | ||
|---|---|---|---|---|
| CTV | V95% (%) | 98.72 ± 1.90 | 99.98 ± 0.02 | 99.97 ± 0.07 |
| PTV | V90% (%) | 99.44 ± 1.07 | 99.54 ± 0.61 | 99.84 ± 0.17 |
| V95% (%) | 98.83 ± 0.74 | 98.71 ± 1.28 | 99.17 ± 0.64 | |
| UI | 1.10 ± 0.02 | 1.11 ± 0.03 | 1.04 ± 0.02#,* | |
| CI | 1.16 ± 0.07 | 1.14 ± 0.06 | 1.13 ± 0.04 | |
| Normal liver | V10 (%) | 64.81 ± 17.86 | 51.91 ± 21.56 | 72.51 ± 13.31* |
| V20 (%) | 41.36 ± 13.99 | 32.62 ± 14.95 | 32.78 ± 9.18 | |
| V30 (%) | 21.10 ± 7.90 | 17.17 ± 8.85 | 17.00 ± 6.10 | |
| mean (Gy) | 18.23 ± 3.11 | 16.14 ± 4.61 | 17.93 ± 2.83 | |
| Stomach | mean (Gy) | 11.68 ± 5.47 | 9.90 ± 6.18 | 13.19 ± 6.05 |
| Right Kidney | mean (Gy) | 5.07 ± 4.99 | 6.32 ± 5.08 | 9.00 ± 8.94 |
| Left Kidney | mean (Gy) | 2.1 ± 3.03 | 2.36 ± 2.91 | 5.00 ± 5.27 |
| Spinal cord | D1% (Gy) | 20.98 ± 7.51 | 20.12 ± 9.08 | 22.53 ± 3.31 |
The Vx is the percentage of normal liver volume that receives ≥ × Gy in the total normal liver volume.
V90 and V95 mean volume covered by 90% and 95% of prescribed dose, respectively.
UI: Uniformity index; CI: Conformal index.
#: The p value is < 0.05 for comparing tomotherapy with coplanar IMRT.
*: The p value is < 0.05 for comparing tomotherapy with noncoplanar IMRT.