Comparison of Anisotropic Analytical Algorithm and Acuros XB Calculation Algorithms on Intensity-modulated Radiotherapy and Volumetric Modulated Arc Therapy Techniques for Nasal Cavity and Paranasal Sinus Tumors: Effects on Integral Radiation Dose

Abstract

OBJECTIVEThis study aims to investigate the dosimetric effects of Acuros XB (AXB) and Anisotropic Analyticalalgorithms (AAA) on intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy(VMAT) techniques for nasal cavity and paranasal sinus tumors.METHODSThis study included 10 patients with the nasal cavity and paranasal sinus tumors, and 7-field non-coplanar IMRT plan and VMAT plans were generated with 6-MV photon beams specially selected for eachpatient anatomy. The effects on planning target volume (PTV) and organ-at-risk (OAR) were evaluatedusing AXB and AAA in each treatment technique to compare the accuracy of the calculation.RESULTSConformity Index (CI) values for PTV were found to be 1.02±0.02 and 1.03±0.03 for VMATAAA andVMATAXB plans, respectively and 1.18±0.03 and 1.20±0.02 for IMRTAAA and IMRTAXB plans, respectively.Regarding heterogeneity index (HI) values, VMATAAA and VMATAXB plans (0.025±0.02; 0.029±0.02)were found to have better HI values than IMRTAAA and IMRTAXB plans (0.246±0.02; 0.335±0.03). Depending on the technique and algorithm used, a dose difference of 4%-14% was detected between PTVDmin values.CONCLUSIONThe selection of AXB algorithm in treatment regions with high tissue heterogeneity will give more accurate dose calculation results for PTV and healthy tissues.