Comparison of different dose calculation algorithms used in brachytheraphy

In this thesis study, dose distributions of HDR 192Ir source were evaluated in different scenarios on virtual phantoms and computed tomography sections using Eclipse TG-43 formalism, Acuros®BV and Monte Carlo-based BrachyDose code. Primarily, multiple source (single, three, five source) planted homogenous water phantom and heterogeneous rectangular phantom scenarios and tomography sections obtained from patients with cervical cancer were selected as the dose calculation medium. In all scenarios dose distribution was calculated using TG-43 and model-based algorithms. After transferring BrachyDose dose files to Eclipse TPS, dose distribution was assessed using dose profiles, isodose curves, and DVH. In homogeneous water phantom, all algorithms gave similar results. The difference between TG-43 and model-based algorithms is within 9% in heterogeneous phantom scenarios and around 42% in patient plans. The highest differences were observed in plans containing Al and a high number of sources. The difference between model-based algorithms is around 2% in all scenarios. The difference between Acuros®BV and BrachyDose is within 6.6% in CTV, 2% in the rectum, 10% for the bladder and sigmoid. There is no difference between model based algorithms in bone structures.