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PET/MRI technology has expanded the boundaries of investigation in nuclear medicine, supported by the high sensitivity of solid-state PET detectors. Nonetheless, the coil positioning might lead to an increased exposure period of the worker to the injected patient. This procedure does not occur on PET/CT and, therefore, exposure period is reduced on such scanner. The aim of our study was to evaluate the dosimetry of two occupationally exposed individuals (OEI) working at the Center of Nuclear Medicine of Hospital das Clínicas of the University of Sao Paulo. We used thermoluminescent (TLD) dosimeters in pulse, whole-body and crystalline for PET/MRI and PET/CT procedures during five months of clinical and research routine. We also monitored the time for positioning/removing the patient on both scanners. For this study, OEI1 performed 76 PET/MRI studies and 102 PET/CT studies while OEI2 performed 26 and 56 PET/MRI and PET/CT studies, respectively. We found no evidence of differences for the whole-body dose values between both scanners (p = 0.22). The average time of patient management (positioning/removing the patient) was 14.38, and 3.81 minutes for PET/MRI and PET/CT, respectively. When the normalization by the number of PET/CT studies was applied, we found no statistical difference for effective and equivalent dose values. Our study encourages future investigations on nursing staff, which is a critical population that is exposed to ionizing radiation, mainly on dynamic studies, due to the synchronized injection with the protocol starting.

O objetivo deste trabalho foi realizar uma revisão narrativa do cenário mundial dos radiofármacos para diagnóstico e estadiamento de câncer de próstata (CaP). A revisão foi realizada utilizando o seletor de busca PUBMED a partir dos termos: (Prostate cancer and PET), 18F-FDG, N-3-[18F]fluoropropylputrescine [1], 11C- Acetate [2], 18F- Acetate, 11C-Colina [3], 18F-Fluorometilcolina, 68Ga-PSMA-HBED-CC, 18F-FDCFBC, 18F-FACBC, 18F-DCFPyL, Al18F-PSMA-11 e 18F-PSMA-1007. A pesquisa foi realizada considerando o período de 1989 a 2019. Os radiofármacos 11C-Colina e 18F-FCH foram durante vários anos os biomarcadores de imagem molecular padrão para CaP. Contudo, o 68Ga-PSMA-11, devido a melhor acurácia e facilidade de obtenção, viabilizou que clínicas de medicina nuclear, distantes de unidades produtoras de radiofármacos, realizassem exames no PET/CT ou PET/RM, tornando-se o radiofármaco mais utilizado atualmente em diagnóstico e estadiamento de CaP. Radiofármacos fluorados para próstata também foram desenvolvidos na tentativa de substituir o 68Ga-PSMA-11 e reduzir a dependência das clínicas com os geradores de 68Ge/68Ga. Nesse sentido, os radiofármacos fluorados mais destacados na literatura nos últimos cinco anos foram: 18F-FACBC, 18F-DCPyL, Al18F-PSMA-11 e 18F-PSMA-1007. Através dessa revisão, verificamos uma lacuna na literatura acerca da comparação entres esses radiofármacos devido às dificuldades de obtê-los para fins de pesquisa e, principalmente, às patentes do 18F-DCPyL e 18F-PSMA-1007. A literatura encoraja estudos de maior impacto na comparação da eficácia dos radiofármacos. A tendência é o crescimento de radiofármacos a base de 18F, como o 18F-PSMA-1007 e 18F-DCPyL devido, principalmente, a excreção renal tardia que eles proporcionam.

The number of units producing radiopharmaceuticals with a half-life of fewer than two hours has increased with the growth of PET technology in Brazil. In the production of such radiopharmaceuticals such as 18F-FDG or 11C-PIB, gaseous waste is formed. The International Atomic Energy Agency (IAEA) proposes a methodology that can be used to evaluate the dispersion of these gaseous effluents. This work has retrospectively evaluated the emission of radioactive gaseous effluents generated in the production of 18F-FDG, in order, to delimit yield values of radioactive waste in the gaseous form and to verify the effectiveness and the design of the safety elements of the exhaust system evaluated before the standards of the National Nuclear Energy Commission (CNEN) and IAEA recommendations. Thirty-six productions of 18F-FDG were found.