Simulación de un fantoma de mama para dosimetría, utilizando Montecarlo

Abstract

The present research was aimed to simulate a breast phantom in order to perform the dosimetry analysis applying the Montecarlo method. It was developed a breast phantom model and the devices of mammography equipment such as, a Mo target with a Mo filter for 26, 28 and 30 keV, the half-conductor layer of Al and the polycarbonate compressor paddle. The breast phantom had a box shape and was located 600 mm far from the source. For dosimetric analysis, the study considered three breast compression thicknesses 40, 45 and 50 mm each one with five compositions of breast tissue 1:99, 25:75, 50:50, 75:25, 99:1 (glandular T. : adipose T.) The materials for the formation of the devices and the phantom were taken from the NITS and ICRU 44 databases present on the GAMOS platform. It was determined that the energy deposited in each volumen as a function of the kilovoltage it was directly proportional, while depending on the thickness of the compressed breast, it had an inversely proportional relationship to the composition of the breast phantom. The Mean Glandular Dose (MGD) per photon decreased to a higher percentage of glandular tissue and thickness of compressed breast. The MGD in standard compositions (50:50), analyzed in 33.55, 38.55 and 43.55 mm thickness increases, it is also within the reference limit. In conclusion, the simulation was useful for the analysis of dosimetry in the breast, and it is recommended to extend the study by simulating and anthropomorphic breast phantom, in addition to contrasting the simulated data with real data collected in imaging centers, establishing reference levels of this radiological technique in the country.