Table 6.
Ion chamber measurements in comparison to the treatment planning system-calculated dose at the ArcCHECK isocenter for the task group 119 test cases from the analytical anisotropic algorithm and Acuros XB algorithm-calculated RapidArc plans for the Clinac-iX (6 MV) and TB-STx (6MV_filtered beam and 6MV_flattening filter-free beam), respectively
| Structure | IC versus TPS calculation (% difference) | |||||
|---|---|---|---|---|---|---|
| Clinac-iX (6MV FB) | TB-STx (6MV FB) | TB-STx (6MV FFFB) | ||||
| AAA | AXB | AAA | AXB | AAA | AXB | |
| C shape (easier) | 3.4 | 4.7 | 4.1 | 4.6 | 4.4 | 4.9 |
| C shape (hard) | −2.7 | 2.5 | 2.2 | 2.3 | 3.2 | 3.6 |
| H and N | 2.4 | 2.6 | 1.6 | 3.5 | −0.7 | 1.7 |
| Multitarget | 1.4 | 1.2 | 1.3 | 1.1 | −2.0 | −0.3 |
| Prostate | 2.8 | 0.5 | 4.1 | 4.6 | 2.0 | 1.9 |
| Mean±SD | 1.5±2.5 | 2.3±1.6 | 2.7±1.4 | 3.2±1.5 | 1.4±2.7 | 2.3±2.0 |
TPS: Treatment planning system, IC: Ion Chamber, TB: TrueBeam, FFF: Flattening filter free, AAA: Analytical anisotropic algorithm, AXB: Acuros XB, SD: Standard deviation