Table 2.
CTV and PTV dosimetric parameters according to treatment techniques for all patients
| Target structure | Dosimetric parameter | nc-IMRTa | nc-VMATb | Hybrid IMRT/VMATc | Pairwise comparison |
|---|---|---|---|---|---|
| CTV | D2% (Gy) | 69.36 ± 0.13 | 69.36 ± 0.17 | 69.10 ± 0.25 | b versus c (0.001*) a versus c (<0.001*) |
| D98% (Gy) | 64.72 ± 0.81 | 64.51 ± 0.89 | 64.73 ± 0.74 | a versus b (0.10) b versus c (0.08) | |
| D50% (Gy) | 67.21 ± 0.16 | 67.37 ± 0.31 | 66.83 ± 0.49 | b versus c (0.009*) a versus c (0.06) | |
| V95% (%) | 99.22 ± 0.62 | 99.33 ± 0.52 | 99.45 ± 0.45 | NS† | |
| CN | 0.55 ± 0.04 | 0.55 ± 0.05 | 0.57 ± 0.05 | b versus c (0.006*) | |
| HI | 0.07 ± 0.01 | 0.07 ± 0.01 | 0.06 ± 0.01 | b versus c (0.002*) a versus c (<0.001*) | |
| PTV | D2% (Gy) | 69.34 ± 0.14 | 69.34 ± 0.18 | 68.97 ± 0.25 | b versus c (0.002*) a versus c (<0.001*) |
| D98% (Gy) | 61.29 ± 1.48 | 61.44 ± 1.57 | 61.44 ± 1.61 | NS† | |
| D50% (Gy) | 67.14 ± 0.23 | 67.22 ± 0.26 | 66.85 ± 0.20 | b versus c (0.007*) a versus c (< 0.001*) | |
| V95% (%) | 97.88 ± 0.66 | 97.94 ± 0.71 | 97.96 ± 0.74 | NS† | |
| V107% (%) | 1.02 ± 0.54 | 1.01 ± 0.56 | 0.52 ± 0.46 | b versus c (0.026*) a versus c (0.001*) | |
| CN | 0.72 ± 0.02 | 0.72 ± 0.05 | 0.74 ± 0.04 | b versus c (0.034*) | |
| HI | 0.12 ± 0.02 | 0.12 ± 0.02 | 0.11 ± 0.02 | NS† |
CTV = clinical target volume; PTV = planning treatment volume; D(X%) = dose (Gy) received by (X%) of structure; V(X% or X Gy) = percentage volume of structure receiving dose (X% or X Gy) or more; CN = conformation number; HI = homogeneity index; NS = non-significant
*Significant (P < 0.05).
† P > 0.1.