Table 3.
Summary of OARs and NT dose distribution for VMAT-S, IMRT and HT plans
| Structures | V 10 | V 20 | V 30 | V 40 | V 50 | D mean (Gy) | |
|---|---|---|---|---|---|---|---|
| Bowel |
Mean (VMAT-S) |
0.88 |
0.70 |
0.39 |
0.22 |
0.08 |
27.35 |
| Mean (IMRT) |
0.83 |
0.66 |
0.40 |
0.22 |
0.09 |
26.72 |
|
|
P |
0.02 |
0.03 |
0.15 |
0.27 |
0.39 |
0.02 |
|
| Mean (HT) |
0.91 |
0.72 |
0.38 |
0.19 |
0.08 |
26.91 |
|
|
P |
0.07 |
0.08 |
0.13 |
0.10 |
0.61 |
0.03 |
|
| Rectum |
Mean (VMAT-S) |
0.99 |
0.96 |
0.82 |
0.54 |
0.25 |
40.33 |
| Mean (IMRT) |
0.98 |
0.96 |
0.93 |
0.63 |
0.27 |
42.40 |
|
|
P |
0.19 |
0.52 |
0.03 |
0.00 |
0.06 |
0.01 |
|
| Mean (HT) |
1.00 |
0.98 |
0.85 |
0.57 |
0.25 |
40.99 |
|
| |
P |
0.21 |
0.31 |
0.31 |
0.08 |
0.36 |
0.12 |
| Bladder |
Mean (VMAT-S) |
1.00 |
0.96 |
0.67 |
0.35 |
0.16 |
36.23 |
| Mean (IMRT) |
0.99 |
0.91 |
0.70 |
0.38 |
0.17 |
36.33 |
|
|
P |
0.36 |
0.03 |
0.03 |
0.04 |
0.37 |
0.17 |
|
| Mean (HT) |
1.00 |
0.86 |
0.65 |
0.33 |
0.14 |
35.09 |
|
|
P |
0.52 |
0.02 |
0.16 |
0.08 |
0.38 |
0.06 |
|
| Pelvic bones |
Mean (VMAT-S) |
0.91 |
0.73 |
0.40 |
0.22 |
0.08 |
27.85 |
| Mean (IMRT) |
0.84 |
0.65 |
0.45 |
0.25 |
0.09 |
27.28 |
|
|
P |
0.00 |
0.00 |
0.03 |
0.03 |
0.17 |
0.13 |
|
| Mean (HT) |
0.91 |
0.69 |
0.41 |
0.24 |
0.09 |
28.22 |
|
|
P |
0.51 |
0.08 |
0.07 |
0.06 |
0.53 |
0.61 |
|
| Normal tissue |
Mean (VMAT-S) |
0.79 |
0.45 |
0.21 |
0.11 |
0.05 |
20.48 |
| Mean (IMRT) |
0.68 |
0.42 |
0.21 |
0.12 |
0.05 |
19.77 |
|
|
P |
0.00 |
0.03 |
0.15 |
0.15 |
0.25 |
0.08 |
|
| Mean (HT) |
0.81 |
0.42 |
0.17 |
0.06 |
0.03 |
20.56 |
|
| P | 0.35 | 0.10 | 0.07 | 0.09 | 0.12 | 0.15 |
OARs: organs at risk, NT: normal tissue, VMAT-S: volumetric modulated arc therapy with SmartArc, IMRT: intensity-modulated radiotherapy, HT: helical tomotherapy, V10, V20, V30, V40 and V50: the percentage volume of the OARs and NT receiving a dose of 10, 20, 30, 40 and 50 Gy, respectively, D mean: mean dose.