Table 4.
Dosimetric comparisons for target coverage between VMAT and PBS.
| Target | Parameter | VMAT | PBS (Gy(RBE)) | P-value |
|---|---|---|---|---|
| PTV1 | D95% (Gy) | 45.07 ± 0.10 | 45.36 ± 0.24 | 0.027* |
| D2% (Gy) | 46.93 ± 0.14 | 46.86 ± 0.15 | 0.361 | |
| Dmean (Gy) | 45.94 ± 0.12 | 46.05 ± 0.05 | 0.128 | |
| V105% (cm3) | 2.34 ± 2.96 | 1.44 ± 1.39 | 0.601 | |
| CN95% | 0.76 ± 0.02 | 0.77 ± 0.89 | 0.856 | |
| CN100% | 0.89 ± 0.03 | 0.96 ± 0.04 | 0.843 | |
| HI2-98% | 0.05 ± 0.01 | 0.04 ± 0.01 | 0.587 | |
| Vol. cm3 | 729.29 ± 131.77 (576.25–893.97) | |||
| PTV2 | D95% (Gy) | 34.33 ± 0.11 | 34.39 ± 0.08 | 0.227 |
| D2% (Gy) | 35.45 ± 0.34 | 35.52 ± 0.17 | 0.670 | |
| Dmean (Gy) | 34.89 ± 0.24 | 34.87 ± 0.03 | 0.902 | |
| V105% (cm3) | 0.29 ± 0.47 | 0.25 ± 0.44 | 0.570 | |
| CN95% | 0.78 ± 0.04 | 0.78 ± 0.93 | 0.905 | |
| CN100% | 0.92 ± 0.05 | 0.03 ± 0.04 | 0.827 | |
| HI2-98% | 0.04 ± 0.01 | 0.04 ± 0.01 | 0.749 | |
| Vol. cm3 | 89.64 ± 16.80 (69.23–109.21) | |||
PTV, planning target volume; Gy(RBE); gray(radiobiological equivalent); VMAT, volumetric modulated arc therapy; PBS, pencil beam scanning; Dx, dose received by target at a defined volume (x) in percentage; Vx, volume of target receiving a defined dose (x) in Gray; CN, conformation number; HI, homogeneity index; *p < 0.05, statistically significant.