Table 3 Plan parameters and significance of differences based on the pooled data of five patients and five institutes
VMAT average ± 1 SD* | IMRT average ± 1 SD* | Average difference ± 1 SD* (VMAT – IMRT) | p-value (Wilcoxon’s signed-rank test)^ | ||
|---|---|---|---|---|---|
PTVboost | CI95 | 1.37 ± 0.08 | 1.45 ± 0.11 | -0.08 ± 0.09 | .001 |
PTVtotal | CI95 | 1.50 ± 0.09 | 1.62 ± 0.10 | -0.12 ± 0.07 | < .001 |
Normal tissue | V5Gy (cm3) | 5050 ± 730 | 5030 ± 750 | -20 ± 260 | n.s. |
V10Gy (cm3) | 4050 ± 630 | 3970 ± 590 | -80 ± 160 | n.s. | |
V20Gy (cm3) | 2830 ± 510 | 2860 ± 480 | 30 ± 150 | n.s. | |
Spinal cord | Dmax (Gy) | 45.1 ± 3.5 | 46.6 ± 3.0 | -1.5 ± 2.3 | .001 |
D1% (Gy) | 43.4 ± 3.7 | 44.4 ± 3.5 | -0.9 ± 2.2 | .005 | |
Dmean (Gy) | 29.3 ± 4.4 | 29.8 ± 3.6 | -0.5 ± 2.4 | n.s. | |
Brain stem | Dmax (Gy) | 46.4 ± 5.4 | 47.1 ± 4.7 | -0.7 ± 4.6 | n.s. |
D1% (Gy) | 43.8 ± 5.8 | 44.0 ± 5.5 | -0.2 ± 4.9 | n.s. | |
Dmean (Gy) | 13.6 ± 3.6 | 14.5 ± 4.3 | -1.0 ± 2.4 | n.s. | |
Parotid gland ipsilateral | V25Gy (%) | 42.9 ± 15.6 | 50.3 ± 20.0 | -7.4 ± 14.0 | < .001 |
V39Gy (%) | 30.0 ± 14.6 | 35.9 ± 18.6 | -5.9 ± 11.2 | < .001 | |
Dmean (Gy) | 28.0 ± 7.5 | 31.1 ± 9.1 | -3.1 ± 5.1 | < .001 | |
Parotid gland contralateral | V25Gy (%) | 31.0 ± 7.1 | 34.5 ± 6.8 | -3.5 ± 3.6 | < .001 |
V39Gy (%) | 18.3 ± 6.0 | 20.8 ± 6.1 | -2.5 ± 2.5 | < .001 | |
Dmean (Gy) | 22.0 ± 2.9 | 23.3 ± 2.8 | -1.3 ± 1.5 | < .001 | |
Submandibular gland contralateral$ | V39Gy (%) | 88.1 ± 15.3 | 90.8 ± 13.5 | -2.7 ± 6.9 | n.s. |
V60Gy (%) | 16.4 ± 21.4 | 21.8 ± 27.3 | -5.5 ± 8.5 | .020 | |
Dmean (Gy) | 53.0 ± 5.9 | 54.2 ± 6.1 | -1.3 ± 1.8 | .027 | |
Oral cavity | V25Gy (%) | 79.8 ± 22.9 | 86.3 ± 15.7 | -6.5 ± 10.2 | .011 |
V39Gy (%) | 40.6 ± 22.0 | 48.8 ± 23.3 | -8.2 ± 12.4 | .002 | |
Dmean (Gy) | 36.7 ± 7.8 | 39.4 ± 7.3 | -2.7 ± 2.8 | < .001 | |
Larynx | V39Gy (%) | 75.4 ± 24.7 | 79.1 ± 21.6 | -3.8 ± 6.7 | .012 |
V45Gy (%) | 54.1 ± 27.4 | 58.2 ± 26.5 | -4.1 ± 9.3 | n.s. | |
Dmean (Gy) | 45.5 ± 5.3 | 46.5 ± 4.4 | -1.0 ± 1.5 | .004 | |
Pharyngeal constrictors° | V39Gy (%) | 78.7 ± 24.5 | 81.5 ± 20.0 | -2.8 ± 15.2 | n.s. |
V45Gy (%) | 59.7 ± 29.4 | 57.5 ± 25.5 | 2.2 ± 19.9 | n.s. | |
Dmean (Gy) | 47.1 ± 5.3 | 46.9 ± 3.8 | 0.2 ± 2.7 | n.s. | |
Mandible° | V39Gy (%) | 74.0 ± 13.1 | 78.2 ± 11.8 | -4.2 ± 8.4 | .025 |
V60Gy (%) | 25.7 ± 15.0 | 30.1 ± 16.2 | -4.4 ± 5.1 | < .001 | |
Dmean (Gy) | 48.6 ± 5.5 | 50.3 ± 5.7 | -1.7 ± 1.7 | < .001 | |
Effective delivery time# | (min:sec) | 5:54 ± 1:05 | 13:15 ± 1:38 | -7:21 ± 1:55 | < .001 |
MUs | -- | 643 ± 111 | 828 ± 149 | -185 ± 129 | < .001 |