Avaliação da dose fetal em procedimento de medicina nuclear utilizando simulação Monte Carlo

Abstract

The use of radionuclides in Nuclear Medicine is essential for diagnostic and therapeutic procedures, with 99mTc being the most commonly used. Although its use is well understood in terms of radiation protection and also in extremely rare situations such as procedures performed on pregnant women, greater attention must be given. To assess how pregnant women are exposed to these procedures, a study was conducted using computational simulations employing the MCNPX2.7.0 code. A simulation model, based on voxels of a pregnant woman at 24 weeks gestation and the definition of the 99mTc photon source to transport internally emitted radiation within a voxel-based anthropomorphic simulator, were utilized. The highest S values (mGy/MBq.s) were found in cases where the spleen and uterus were source organs. The spleen contributed to a higher dose in the pregnant woman with an S value of 1,0 E-05 mGy/MBq.s, and the uterus contributed to a higher dose in the fetus with value of 1,3 E-06 mGy/MBq.s.