Comparision of three-dimentioanal treatment planning algorithms verifications for inhomogenity body structure by dosimetry

In this study, Elekta Precise model linear accelarator using 6 MV and 18 MVx-ray beams was utilized in ESOGU Radiation Oncology department.Measured-based and model-based algorithms verifications in CMS XiO model4.2.2. version Treatment Planning System (TPS) were compared by usingrandophantom for inhomogen body structure. Computirized Tomography (CT)images of randophantom were taken and 3-D patient images were produced inTPS.Inhomogeneity treatment fields, in the field of 15x15 cm2 anterior-posteriorin both right lung, mediastinum and 10x10 cm2 right-left lateral in craniumwere irratiated bu using SAD (Source Axis Distance) technique with TPS?scomputation time. The both algorithms verifications for inhomogeneitytreatment fields were evaluated by using film dosimetry. In conclusion, modelbased algorşthms for lung inhomogeneity in the limit of ±%2 and measuredbased algorithms in the limit of ±%5 with film dosimetry. The both algorithmsfor cranium inhomogeneity was within ±%2 with film dosimetry.