Dose distribution evaluation of various dose calculation algorithms in inhomogeneous media

Background: Dose calcula on algorithms play a very important role in predic ng the explicit dose distribu on. We evaluated the percent depth dose (PDD), lateral depth dose profile, and surface dose volume histogram in inhomogeneous media using calcula on algorithms and inhomogeneity correc on methods. Materials and Methods: The homogeneous and inhomogeneous virtual slab phantoms used in this study were manufactured in the radia on treatment planning system to represent the air, lung, and bone density with planned radia on treatment of 6 MV photons, a field size of 10 × 10 cm², and a source-to-surface distance of 100 cm. Results: The PDD of air density slab for the Acuros XB (AXB) algorithm was differed by an average of 20% in comparison with other algorithms. Rebuild up occurred in the region below the air density slab (10-10.6 cm) for the AXB algorithm. The lateral dose profiles for the air density slab showed rela vely large differences (over 30%) in the field. There were large differences (20.0%-26.1%) at the second homogeneous-inhomogeneous junc on (depth of 10 cm) in the field for all calcula on methods. The surface dose volume histogram for the pencil beam algorithm showed a response that was approximately 4% lower than that for the AXB algorithm. Conclusion: The dose calcula on uncertain es were shown to change at the interface between different densi es and in varied densi es using the dose calcula on methods. In par cular, the AXB algorithm showed large differences in and out of the field in inhomogeneous media.