Table 1: Mean (σ) values of DVH metrics calculated by TPS and 3DVH for no error and error introduced plans in studied prostate and head and neck VMAT plans.
| Rectum V60 (%) | |||||||
| Error scenario | Magnitude of error | Mean dose (Gy) | D95 (Gy) | ||||
| 3DVH | TPS | 3DVH | TPS | 3DVH | TPS | ||
| No error | 77.8 (2.1) | 78.4 (1.7) | 74.9 (2.9) | 75.4 (2.7) | 21.3 (9.0) | 20.5 (7.8) | |
| Gantry angle independent MLC error | ±1 mm | 78.1 (1.9) | 78.4 (1.7) | 75.2 (2.7) | 75.2 (2.8) | 21.3 (8.3) | 20.5 (7.8) |
| ±5 mm | 77.3 (2.8) | 77.0 (2.5) | 74.2 (3.3) | 69.8 (5.4) | 21.6 (8.0) | 18.6 (7.7) | |
| Gantry angle dependent MLC error | 1 mm | 78.0 (1.8) | 78.2 (1.7) | 74.8 (2.5) | 75.3 (2.8) | 19.0 (5.9) | 20.6 (7.0) |
| 7 mm | 79.2 (1.7) | 77.7 (2.1) | 75.7 (2.2) | 64.0 (7.5) | 22.3 (7.6) | 13.4 (18.3) | |
| Gantry angle dependent dose error | 1 % | 76.7 (1.0) | 78.1 (1.6) | 73.5 (1.6) | 74.6 (2.5) | 22.5 (3.5) | 26.2 (16.5) |
| 7 % | 76.8 (1.1) | 78.1 (1.4) | 73.2 (1.7) | 74.6 (2.6) | 22.4 (3.2) | 25.7 (15.2) | |
| Spinal cord D2cc(Gy) | |||||||
| Mean dose (Gy) | D95(Gy) | ||||||
| No error | 59.7 (4.4) | 60.4 (4.4) | 51.2 (3.8) | 52.3 (3.9) | 36.0 (5.0) | 36.2 (4.4) | |
| Gantry angle independent MLC error | ±1 mm | 59.7 (4.1) | 60.4 (4.3) | 51.2 (3.9) | 52.3 (3.8) | 35.9 (5.0) | 36.3 (4.4) |
| ±5 mm | 59.5 (4.8) | 60.4 (4.7) | 51.1 (4.5) | 55.3 (8.2) | 35.8 (5.3) | 36.2 (4.7) | |
| Gantry angle dependent MLC error | 1 mm | 59.2 (5.6) | 60.5 (4.6) | 50.7 (5.5) | 55.4 (8.0) | 35.6 (5.4) | 35.9 (4.9) |
| 7 mm | 57.9 (7.6) | 60.3 (4.3) | 49.7 (6.8) | 53.2 (6.7) | 34.5 (6.2) | 34.4 (6.1) | |
| Gantry angle dependent dose error | 1 % | 57.5 (2.8) | 60.4 (4.7) | 49.6 (2.8) | 52.3 (4.1) | 36.0 (6.1) | 36.2 (4.7) |
| 7 % | 63.7 (7.3) | 61.4 (5.0) | 57.5 (9.3) | 52.1 (4.8) | 37.7 (7.1) | 37.9 (6.2) | |