Table 2.
Dose-volumetric parameters of the PTV
| DV parameter | VMAT | IMRT with MR-linac | p |
|---|---|---|---|
| D98% (Gy) | 59.1 ± 0.3 | 60.3 ± 1.1 | < 0.001 |
| D95% (Gy) | 60.0 ± 0.0 | 60.7 ± 1.2 | 0.015 |
| D5% (Gy) | 64.9 ± 1.3 | 63.8 ± 1.6 | 0.026 |
| D2% (Gy) | 65.3 ± 1.4 | 64.2 ± 1.7 | 0.035 |
| Minimum dose (Gy) | 54.6 ± 1.4 | 58.7 ± 1.3 | < 0.001 |
| Maximum dose (Gy) | 66.8 ± 1.3 | 63.8 ± 1.5 | < 0.001 |
| Mean dose (Gy) | 63.0 ± 0.8 | 62.3 ± 1.4 | 0.047 |
| PTV volume (cm3) | 27.2 ± 23.5 (ITV + 5 mm) | 6.3 ± 7.7 (GTV + 3 mm) | < 0.001 |
| Homogeneity index | 0.099 ± 0.023 | 0.062 ± 0.014 | < 0.001 |
Note: DV parameter dose-volumetric parameter, VMAT volumetric modulated arc therapy, IMRT intensity modulated radiation therapy, MR-linac magnetic resonance image linear accelerator, Dn% dose received by at least n% volume of the planning target volume, PTV planning target volume, ITV internal target volume, GTV gross tumor volume