Technical note: Dosimetric study for the new BEBIG Co HDR source used in brachytherapy in water and different media using Monte Carlo N-Particle eXtended code.

This work aims to study the dosimetrc parameters of the new Co-source model Co0.A86 used in high dose rate brachytherapy and manufactured by BEBIG (Eckert & Ziegler BEBIG GmbH, Germany). The radial dose function, 2D along&away dose rates and the dose rate constant were investigated in a water phantom. Accordingly, we use the recommendations from the AAPM and ESTRO on dose calculation for high-energy (average energy higher than 50 keV) photon-emitting brachytherapy sources cited in the HEBD working group report. Furthermore, we compared the obtained results with the quoted values in the previous studies. The value of air-kerma strength calculated in this work was 3.030 ± 0.002 UBq. Moreover, the radial dose function and 2D along&away dose rates are evaluated in different tissues and compared with the results obtained in the water and we found a notable difference. To reach the goal we have used MCNPX code for simulation.