| Popis: |
The aim of this study was to validate Acuros XB (AXB) algorithm for photon dose calculation on an indigenously fabricated low-density heterogeneous phantom. Phantom was fabricated using poly (methyl methacrylate) (PMMA) and racemosa wood. The measured Hounsfield units, relative electron density, and mass density were 726.5, 0.273, and 0.212 g/cc and 201.8, 1.201, and 1.175 g/cc for racemosa and PMMA, respectively. AXB results were compared against anisotropic analytical algorithm (AAA) and ion chamber (IC) measured data for 3 cm × 3 cm and 10 cm × 10 cm field size of 6 megavolts beam. AXB results were in better agreement with IC measured data at all measuring points in comparison to AAA. The discrepancies between AXB and IC measured data were 1.3%–2.2% for 3 cm × 3 cm, −1.5%–−0.9% for 10 cm × 10 cm at low-density region, and −3.6%–−1.6% for 3 cm × 3 cm, and −1.4%–−0.8% for 10 cm × 10 cm at secondary buildup region, whereas discrepancies between AAA and measured data were 1.6%–3.6% for 3 cm × 3 cm, −4.6%–−3.4% for 10 cm × 10 cm at low-density region, and within −5.3%–−2.1% for 3 cm × 3 cm and −1.5%–1.0% for 10 cm × 10 cm at the secondary build-up region. Therefore, AXB is more appropriate in dealing with low-density heterogeneity in comparison to AAA. |
