Avaliação dosimétrica em profissionais durante o procedimento de Nefrolitotomia Percutânea utilizando simulação Monte Carlo

Abstract

This study aims to evaluate the radiation doses that professionals receive during the percutaneous nephrolithotomy procedure, which consists of removing kidney stones with the help of interventional radiology. The dose study was carried out using computer simulation, in this case the Monte Carlo simulation method was used. Scenarios were constructed using the Monte Carlo N-Particle Transport (MCNP), version 6.2, of a percutaneous nephrolithotomy procedure for the anteroposterior (AP), right anterior oblique, 30° (RAO30) and left anterior oblique, 30° (LAO30) projections. In this work, virtual anthropomorphic phantoms were used, including two patients with different body mass indexes (M10_H10 and M90_H90) to analyze the influence of different body mass index (BMI) on the scattered radiation to the main and assistant physicians, which were represented with the MASH3 virtual phantom. The analysis included the use of individual and collective protective equipment, to study how effective this protective equipment is in reducing the doses received by professionals. The tube voltage used for all scenarios was 70 kV, the field size was 11 × 11 cm, the experimental kerma-area product used was 27 Gy.cm² and the modeled X-ray equipment was the Siemens SIREMOBIL Compact L. The effective doses obtained for the main physician varied within a range of 0.92 µSv to 2.32 µSv with the use of personal and collective protective equipment for the scenarios with the three projections and different patients. Without the use of protective equipment, the effective dose values ranged from 17.8 µSv to 41.4 µSv. There was a reduction of up to 95% in the effective dose to the main physician with the use of radiation protection equipment. The organs that obtained the highest equivalent dose values to the main physician were the eye lens, eyes, skin, bone marrow (red) and stomach. The equivalent doses found for the principal physician's eyes were reduced by up to 95% with the use of individual and collective protective equipment, ranging from 172 µSv to 393 µSv, and the use of the lead screen on the physician's left side reduced the equivalent dose in the eyes by up to 21%. The equivalent doses found for the main phycisian's brain varied from 0.258 to 0.751 µSv with the use of personal and collective protective equipment, that reduced doses by 86.5%. It was observed that oblique projections increased the radiation dose received by professionals. Comparing the effective doses of the LAO30 with the AP projection, it was observed that the AP projection showed a reduction of up to 51% in dose values.