High dose rate (HDR) brachytherapy is a widely utilized treatment modality in modern clinical brachytherapy. In clinical practice, accurate dosimetric parameters for ¹⁹²Ir HDR brachytherapy sources are essential. Due to the variation in source designs, each model requires specific dosimetric parameters. Although there is extensive international research on the dosimetric parameters of ¹⁹²Ir sources, simulation studies focusing on the dosimetric parameters of HDR ¹⁹²Ir brachytherapy sources produced by the Atomic Hi-Tech (HTA) Co., Ltd are relatively scarce in China.

This study aims to calculate the dosimetric parameters of a domestically produced HDR ¹⁹²Ir source by constructing a detailed structural model of the source using Monte Carlo simulation software, based on the dosimetric calculation methods recommended in the TG-43U1 report by the American Association of Physicists in Medicine (AAPM).

Based on the dosimetric calculation methods recommended in the TG-43U1 report by the American Association of Physicists in Medicine (AAPM), Monte Carlo software was used to simulate the ¹⁹²Ir brachytherapy source, and a detailed structural model of the domestically produced high dose rate ¹⁹²Ir brachytherapy source was established within the Monte Carlo software to accurately conduct the simulation. Then, the dosimetric parameters calculated in the simulation such as the dose rate constant, air kerma strength per unit activity, radial dose function, and anisotropy function were calculated in the simulation and compared with that reported in the literature.

Simulation results show that the simulated dose rate constant is found to be 1.105 cGy·h^-1·U^-1, with a difference of less than 1.2% compared to values reported in the literature. Additionally, the air kerma strength per unit activity is calculated to be 9.788×10^-8 U·Bq^-1, with a discrepancy of 0.23% compared to the literature values. Furthermore, the dosimetric parameters for the radial dose function and anisotropy function obtained in this study show a high degree of consistency with corresponding data from existing literature.

The domestically produced ¹⁹²Ir source model established using the Monte Carlo software demonstrates good consistent dosimetric parameters with the literature-reported dosimetric parameters, indicating that this model can be used for clinical practice applications of domestically produced ¹⁹²Ir sources and has certain guiding significance.