Table 2.
Average dose statistics for coplanar VMAT, noncoplanar VMAT, and 4π plans for all 20 patients
| Plan type | OAR doses (Gy) |
|||||
|---|---|---|---|---|---|---|
| Left kidney (mean) | Right kidney (mean) | Normal liver (mean) | Stomach (maximum) | Cord (maximum) | Body (mean) | |
| cVMAT | 1.42a (2.4) | 2.04 (2.4) | 7.07a (2.6) | 11.15 (6.7) | 6.69a (3.2) | 1.51a (0.6) |
| nVMAT | 1.46a (2.1) | 2.09 (2.5) | 6.97a (2.8) | 10.95a (10.0) | 5.74a (4.0) | 1.51a (0.6) |
| 4π | 0.82 (1.2) | 1.70 (1.4) | 6.01 (2.3) | 7.58 (6.3) | 4.00 (3.7) | 1.46 (0.6) |
| PTV D98% (Gy) | VL>15 (cm3) | V50% (cm3) | R50 | HI | CN | |
|---|---|---|---|---|---|---|
| cVMAT | 49.62a (9.6) | 233.7a (120.8) | 271.5b (185.6) | 3.66b (0.4) | 0.11 (0.03) | 0.94 (0.03) |
| nVMAT | 49.59 (9.7) | 228.7a (122.3) | 287.5b (213.4) | 3.77a (0.5) | 0.10 (0.02) | 0.93 (0.04) |
| 4π | 49.42 (9.7) | 153.9 (84.5) | 210.8 (146.4) | 2.82 (0.3) | 0.11 (0.03) | 0.93 (0.03) |
cVMAT, coplanar volumetric modulated arc therapy; nVMAT, noncoplanar volumetric modulated arc therapy; OAR, organ at risk; PTV, planning target volume; VL>15, volume receiving >15 Gy.
a
Significantly different from 4π with P < .05 (paired, 2-tailed t test).
b
Significantly different from 4π and other VMAT plan type with P < .05 (paired, 2-tailed t test).