Estimation of Radiation Exposure to Workers During [¹⁸F] FDG PET/CT Procedures at Molecular Imaging Center, Oman

Positron-emission tomography (PET) is the imaging modality of choice in oncology. In addition, there are several indications for using PET in cardiology and neurology. The main radiotracer used is the radiolabeled glucose analog [¹⁸F] fluorodeoxyglucose ([¹⁸F] FDG). The high-energy annihilation radiation from positron emission may lead to significant radiation exposure to medical imaging professionals such as technologists and staff nurses, patients, and direct acquaintances of the patient. In this cross-sectional observational study, the effective dose to workers in the Molecular Imaging Center from patients injected with [¹⁸F] FDG is assessed. Dose rates were estimated by a calibrated, portable gamma-ray survey meter at 0.3, 0.5, 1.0, and 2.0 m from 70 patients who underwent whole body [¹⁸F] FDG PET/CT procedure immediately and 2 hours post-injection. Electronic personal dosimeters were used to determine the radiation doses per PET/CT imaging for the five staff who directly involved in handling of the injected patients. The staff includes two technologists, two staff nurses, and one medical physicist. The mean dose rates from patients after injection and standard deviation (μSv/h) for the four distances were 98.1 ± 20.0, 55.3 ± 20.0, 28.2 ± 10.0, and 10.8 ± 5.0, respectively. After 2 hours, the measurements significantly dropped to 45.7 ± 10.0, 23.6 ± 10.0, 9.9 ± 4.0, and 3.7 ± 1.0 μSv/h. The average effective dose values for a technologist from injected patients throughout the procedure of PET/CT study was 4.17 μSv per study or 5 mSv/y. This is less than the annual limit recommended by the International Commission on Radiological Protection of 20 mSv/y received in the medical imaging profession.