A Methodology to Evaluate Occupational Internal Exposure to Fluorine-18

摘要

The application of 18F for diagnostic procedures in nuclear medicine through PET (Positron emissionTomography) has grown significantly worldwide in last years with the increasing in the production and use of thisradionuclide in several countries. This technique presents many advantages in terms of image quality of organfunctions. However, besides the benefits of this technique, the external and internal occupational exposure of theworkers may occur in the various steps of production of the radiopharmaceutical fluordeoxiglicose (~(18)FDG) andduring its clinical use in nuclear medicine departments. Workers involved in such activities are usually monitoredroutinely for the control external exposure. However it is important to have available methods for internalmonitoring promptly after a suspicion of accidental incorporation. Therefore, the objective of this work is todevelop procedures for internal monitoring of ~(18)F in the form of ions fluoride and ~(18)FDG. The NaI (Tl)scintillation detector of the IRD-Whole Body Counter was calibrated for in vivo measurements with ananthropomorphic phantom. The HPGe detection system of the IRD-Bioassay Laboratory was calibrated for invitro measurements of urine samples with 1 and 2 liter plastic bottles containing liquid standard sources. Amethodology, based on standard ICRP models, was established for bioassay data interpretation. The methodspresent enough sensitivities to detect ~(18)F in the human body at levels below 1mSv.