Investigation of two different Optimization Algorithm' effect on the dose distributions in the radiotherapy of breast tumors

Human body composed of organs of different densities. Treatment planning systems use dose calculation algorithms that are constantly being developed in order to accurately calculate the dose distributions of organs of different density, such as lungs. Intermediate dose calculation module, which is capable of tissue correction in inhomogeneous structures, has been added into the Analytical Anisotropic Algorithm (AAA), a dose calculation algorithm. In this study, it was aimed to investigate the contribution of intermediate module to dose distribution in radiotherapy plans of 20 patients with left breast cancer using IMRT technique. In this study treatment plans of 20 left breast cancer patients which has treatment volumes varying between 434,7 cm3 and 1595,2 cm3, have been made by IMRT technique. While treatment plans are being made, the AAA and AAA Intermediate dose calculation algorithms' of Eclipse 8.9.0 TPS and Eclipse 15.6.03 TPS have been used. Normalization has been made to make %95 of PTV have the prescription dose were created. The treatment plans have been prepared for each patient by using and without intermediate module; have been compared in terms of homogeneity index (HI), conformity index (CI) for target volume, heart, medulla and lung doses at risk by the help of the DVHs. In the end of the study, some OAR doses had lower, CI and HI values had better results in the plans, which have been made by using Intermediate dose algorithm than other plans. It can be told treatment plan quality increases when Intermediate dose calculation module is used.