Dosimetric evaluation of Acuros XB Advanced Dose Calculation algorithm in heterogeneous media

• Published in: Radiation oncology (London, England) England), 2011-07, Vol.6 (1), p.82-82, Article 82
• Main Authors: Fogliata, Antonella, Nicolini, Giorgia, Clivio, Alessandro, Vanetti, Eugenio, Cozzi, Luca
• Format: Article
• Language: English
• Subjects: AAA; Acuros; Algorithms; Anisotropy; dose calculation algorithm; Gamma Rays; Health aspects; Humans; inhomogeneity; Models, Statistical; Monte Carlo Method; Phantoms, Imaging; Photons; Photons - therapeutic use; Programming Languages; Radiometry - methods; Radiotherapy - methods; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted - methods; Reproducibility of Results; VMC++; Water - chemistry
• ISSN: 1748-717X; 1748-717X
• DOI: 10.1186/1748-717X-6-82

A study was realised to evaluate and determine relative figures of merit of a new algorithm for photon dose calculation when applied to inhomogeneous media. The new Acuros XB algorithm implemented in the Varian Eclipse treatment planning system was compared against a Monte Carlo method (VMC++), and the Analytical Anisotropic Algorithm (AAA). The study was carried out in virtual phantoms characterized by simple geometrical structures. An insert of different material and density was included in a phantom built of skeletal-muscle and HU = 0 (setting "A"): Normal Lung (lung, 0.198 g/cm3); Light Lung (lung, 0.035 g/cm3); Bone (bone, 1.798 g/cm3); another phantom (setting "B") was built of adipose material and including thin layers of bone (1.85 g/cm3), adipose (0.92 g/cm3), cartilage (1.4745 g/cm3), air (0.0012 g/cm3). Investigations were performed for 6 and 15 MV photon beams, and for a large (13 × 13 cm2) and a small (2.8 × 13 cm2) field. Results are provided in terms of depth dose curves, transverse profiles and Gamma analysis (3 mm/3% and 2 mm/2% distance to agreement/dose difference criteria) in planes parallel to the beam central axis; Monte Carlo simulations were assumed as reference. Acuros XB gave an average gamma agreement, with a 3 mm/3% criteria, of 100%, 86% and 100% for Normal Lung, Light Lung and Bone settings, respectively, and dose to medium calculations. The same figures were 86%, 11% and 100% for AAA, where only dose rescaled to water calculations are possible. In conclusion, Acuros XB algorithm provides a valid and accurate alternative to Monte Carlo calculations for heterogeneity management.