Experimental validation of deterministic Acuros XB algorithm for IMRT and VMAT dose calculations with the Radiological Physics Center's head and neck phantom
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)
Purpose: The purpose of this study was to verify the dosimetric performance of Acuros XB (AXB), a grid-based Boltzmann solver, in intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT). Methods: The Radiological Physics Center (RPC) head and neck (H and N) phantom was used for all calculations and measurements in this study. Clinically equivalent IMRT and VMAT plans were created on the RPC H and N phantom in the Eclipse treatment planning system (version 10.0) by using RPC dose prescription specifications. The dose distributions were calculated with two different algorithms, AXB 11.0.03 and anisotropic analytical algorithm (AAA) 10.0.24. Two dose report modes of AXB were recorded: dose-to-medium in medium (D{sub m,m}) and dose-to-water in medium (D{sub w,m}). Each treatment plan was delivered to the RPC phantom three times for reproducibility by using a Varian Clinac iX linear accelerator. Absolute point dose and planar dose were measured with thermoluminescent dosimeters (TLDs) and GafChromic registered EBT2 film, respectively. Profile comparison and 2D gamma analysis were used to quantify the agreement between the film measurements and the calculated dose distributions from both AXB and AAA. The computation times for AAA and AXB were also evaluated. Results: Good agreement was observed between measured doses and those calculated with AAA or AXB. Both AAA and AXB calculated doses within 5% of TLD measurements in both the IMRT and VMAT plans. Results of AXB{sub Dm,m} (0.1% to 3.6%) were slightly better than AAA (0.2% to 4.6%) or AXB{sub Dw,m} (0.3% to 5.1%). The gamma analysis for both AAA and AXB met the RPC 7%/4 mm criteria (over 90% passed), whereas AXB{sub Dm,m} met 5%/3 mm criteria in most cases. AAA was 2 to 3 times faster than AXB for IMRT, whereas AXB was 4-6 times faster than AAA for VMAT. Conclusions: AXB was found to be satisfactorily accurate when compared to measurements in the RPC H and N phantom. Compared with AAA, AXB results were equal to or better than those obtained with film measurements for IMRT and VMAT plans. The AXB{sub Dm,m} reporting mode was found to be closer to TLD and film measurements than was the AXB{sub Dw,m} mode. AXB calculation time was found to be significantly shorter (x 4) than AAA for VMAT.
- OSTI ID:
- 22098825
- Journal Information:
- Medical Physics, Vol. 39, Issue 4; Other Information: (c) 2012 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
- Country of Publication:
- United States
- Language:
- English
Similar Records
Experimental verification of the Acuros XB and AAA dose calculation adjacent to heterogeneous media for IMRT and RapidArc of nasopharygeal carcinoma
SU-E-T-199: Comparison Between Acuros XB and AAA in Homogeneous Phantoms for Volumetric Modulated Arc Therapy Plans