Dosimetric study for characterization of a postal system of quality control in brachytherapy

High dose rate Brachytherapy is an essential part of the treatment of several types of cancer. The use of high dose rate ¹⁹²Ir sources requires appropriate calibration in order to ensure the desired level of accuracy of the dose delivered. A GEANT4 program was developed to calculate dosimetric quantities in an acrylic phantom. Thus it was possible to define a methodology for calculating the dose around a brachytherapy source using a thermoluminescent dosimetry formalism in terms of water absorbed dose. An acrylic phantom was proposed and characterized with magnitudes protocol TG-43 calculated by Monte Carlo method. The phantom was irradiated in Varian's brachytherapy equipment Gammamed Plus, the dose and the kerma calculated reference agreed at 0,30%. (author)