Simulaciones Monte Carlo para la estimación de dosis en pulmones asociadas a imágenes tomográficas obtenidas en el tomógrafo “Brilliance Big Bore” del hospital oncológico SOLCA – Quito.

Abstract

Here we report the results of dose calculations in lungs, performed with Monte Carlo (MC) simulations, based on the information from a CT scan belonging to an anonymous patient from the oncology Hospital SOLCA-Quito, Quito-Ecuador. The CT scan was taken with a Brilliance Big Bore scanner in the Radiotherapy Department of the hospital. The scan corresponded to a protocol with the following parameters: 120 kVp, 200 mAs, NT = 24 mm. The DICOM files obtained were segmented using the computational tool MATLAB, this was used to build the voxelized phantom for the Monte Carlo simulations. The MC simulations were performed with the open source software GATE. The doses were calculated for a central axial slice of 5 mm, using a single turn of the gantry; the axial slice under study was composed of 70 884 voxels of 1,36×1,36×5,0 mm3. The doses obtained ranged from 6 to 27 mGy with an average 12,25 ± 0,02 mGy for the right lung and 12,45 ± 0,03 mGy for the left one. This approach allows the specific conditions of both the patient and the irradiation protocol to be taken into account.