Monte Carlo calculation of dosimetry parameters for a brachytherapy source

This study presents the results of calculations of dosimetry parameters for a $^{169}$Yb model brachytherapy source. The calculations were performed by a program code that was written by the authors using the GEANT4.9 software package for Monte Carlo simulation. According to the AAPM TG-43 formalism (the American Association of Physicists in Medicine, Task Group No. 43), the following parameters were deter- mined: the dose-rate constant, radial dose functions, and anisotropy function. To verify the program code, the calculation of the dosimetry parameters of the widespread BEBIG Co0.A86 and BEBIG Ir2.A85-2 sources was carried out. An acceptable fit with the data of other authors was obtained. The data we obtained using the developed and verified program code could be used in dosimetry planning systems.