Table 3.
Plan comparison for planning target volume of gross tumour volume (PGTV), planning target volume (PTV)1, PTV2, monitor units (MUs) and delivery time
| Parameter | Intensity-modulated radiation therapy, mean ± SD (Gy) | SmartArc-based volumetric modulated arc therapy, mean ± SD (Gy) | p-value |
|---|---|---|---|
| PGTV | |||
| D98% | 65.2 ± 2.9 | 64.5 ± 3.4 | 0.140 |
| D2% | 73.5 ± 1.2 | 72.2 ± 1.2 | 0.001 |
| Dmean | 70.7 ± 0.9 | 70.2 ± 0.6 | 0.045 |
| CI | 0.54 ± 0.12 | 0.59 ± 0.12 | <0.001 |
| HI | 1.09 ± 0.03 | 1.05 ± 0.02 | <0.001 |
| PTV1 | |||
| D98% | 58.7 ± 1.9 | 58.8 ± 2.3 | 0.898 |
| D2% | 69.2 ± 2.1 | 68.5 ± 1.9 | 0.036 |
| Dmean | 65.2 ± 1.1 | 64.7 ± 0.8 | 0.023 |
| CI | 0.42 ± 0.07 | 0.49 ± 0.08 | <0.001 |
| HI | 1.17 ± 0.02 | 1.14 ± 0.03 | <0.001 |
| PTV2 | |||
| D98% | 51.9 ± 3.2 | 52.3 ± 2.9 | 0.510 |
| D2% | 65.2 ± 3.8 | 64.4 ± 3.8 | 0.059 |
| Dmean | 58.9 ± 1.3 | 58.4 ± 1.2 | 0.009 |
| CI | 0.47 ± 0.05 | 0.51 ± 0.07 | <0.001 |
| HI | 1.18 ± 0.02 | 1.16 ± 0.03 | 0.001 |
| MUs | 741.9 ± 48.2 | 625.7 ± 66.6 | <0.001 |
| Time (min) | 14.2 ± 1.1 | 6.3 ± 0.4 | <0.001 |
CI, conformity index; D2%, near maximum dose; D98%, near minimum dose; Dmean, mean dose; HI, homogeneity index; SD, standard deviation.