Comparison of intensity modulated arc radiotherapy technique and two different dose calculation algorithms i̇n the radiotherapy of lung cancers

The accuracy of dose calculations in the treatment planning system (TPS) is very important in the treatment of radiotherapy. For this reason, algorithms that will accurately analyze and calculate structures with different electron density in the area to be irradiated are needed. İn our study, the advantages or disadvantages of the two algorithms compared and researchagainst each other if the treatment plans of 20 lung cancer patients with the VMAT technique in the final dose calculation algorithms of Acuros XB (AXB) devoloping with the Analytical Anisotropic Algorithm (AAA) widely used in the Eclipse 15.1 TPS. In all of the treatment plans, the isodose line was selected to receive the prescribed dose as 95% of the target volüme and intermediate dose optimization was used to provide construstive corrections at low concentrations of tissue density such as lungs. In addition, critical organs near the target volüme are protected by keeping the dose limits below. In order to see the differences algorithm in the dose calculation, critical organ and target volume optimization values were kept in the treatment plans equal. Each dose prepared with the VMAT technique was evaluated on the dose-volume histogram (DVH) in terms of target volume, critical organ doses, homogeneity index (HI), comformity index (CI) and monitör units (MU). As a result of the evaluation of the Analytical Anisotropic Algorithm(AAA) and Acuros XB (AXB) dose calculation algorithms, it was concluded that the differences in clinical usage will not be significant. Key Words: AAA, AXB, VMAT, Lung Cancer, Inhomogeneity