Estimación de dosis en el útero en pacientes que han recibido tratamiento con I-131 utilizando el método Monte Carlo bajo el código de programación Geant4

Abstract

The aim of this research project was to develop a simulation of an anthropomorphic phantom to estimate the absorbed dose in the uterus using the Monte Carlo method in a differentiated thyroid cancer treatment. For this purpose, a geometry of the human body of a woman was developed, specifying the urogenital system and the breasts. Considering the bladder as the source organ and the uterus as the target organ, initial simulation parameters were defined for the radiopharmaceutical I-131 with activities of 100, 150, 175 and 200 millicuries at different time intervals and histograms and depth dose profiles were extracted. GAMOS software, a GEANT4-based toolkit widely used in medical physics applications, was used for the simulation. By means of 1x1x1 millimetre detector arrays located in the target organ of the phantom, the dose that reached the uterus was determined. As a result, it was obtained that the dose absorbed by the uterus is 6425x- 19 Grays at 6 months after administering an activity of 200 milli cures. It was then concluded that the Monte Carlo method is the most effective method for estimating the absorbed dose and that women can become pregnant 6 months after administering the activity in a thyroidectomy. It is recommended to perform this study for women receiving with I-131 treatment with higher doses than this research, such as for cases of 3000 millicuries leukaemia or other types of cancer, in order to know the dosimetric history of the patients and to know future adverse effects (deterministic).