RESUMO
Objective The aim of this study was to investigate the radiation dose caused by 18 F-fluorodeoxyglucose (FDG) in PET/CT examination and to optimize the concerned radiation protection. Methods Thirty patients from our conventional PET/CT examination were simple randomly selected, and they all underwent whole body PET/CT imaging. The radioactive dose of injected 18F-FDG was recorded. The internal radiation dose was calculated and the external radiation dose from patients was measured with the 451P-DE-SI ion chamber survey meter. The staff's dose was recorded with thermoluminescent detector (TLD). All dosimetry data were processed and analyzed statistically with Excel 2003. Results The injected radioactive dose of 18F-FDG was (432.9±51.8) MBq, and effective dose equivalent received per patient was (8.23±0.99) roSy. The correlation coefficient (r) of the dose equivalent rate and distance was-0.994 by power function curve fitting, and that of dose equivalent rate and time was - 0.988 by exponential curve fitting. The staff's dose was lower than the annual dose limit. Conclusions The patient's internal radiation dose caused by 18F-FDG in PET/CT examination is low, nonetheless, the clinician should always consider optimizing and minimizing the necessary radiation received by the patients. The patients having been injected with 18F-FDG should stay in one place to decrease their radiation to the public. From the medical point of view in optimizing radiation exposure, there may still be a potential to lower the injected 18F-FDG activity.