Estimation of radiation dose to staff from18F-Fluorodeoxyglucose whole body Positron Emission Tomography/Computed Tomography investigations

Objective: The use of whole body 18F-FDG investigation is now rapidly growing. Unlike in radiology, patients in Nuclear medicine are a source of radiation themselves, since F-18 in 18F-FDG is a Positron emitter. The aim of this study is to measure the amount of radiation dose received by nuclear medicine physicians and staff during injection Methods: As per clinical protocol, the patients are supposed to have minimum period of 4 hours prior to the study. Whole body 18F-FDG PET/CT scans were performed in 35 patients for various indications. The radiation dose from the patients was measured using the portable radiation survey meter, during injection. Results: The maximum radiation exposure during FDG injection was 40 mR/hr to the nuclear medicine physician. The minimum radiation exposure during FDG injection was 6.63 mR/hr to the nuclear medicine physician. This was a pediatric patient and the total activity for this patient was 2.2 mCi. The average radiation exposure during FDG injection was 20.91 mR/hr to the nuclear medicine physician. The maximum radiation exposure after water push was 20 mR/hr to the nuclear medicine physician. The minimum radiation exposure after water push was 3.38 mR/hr. The average radiation exposure after water push was 7.87 mR/hr to the nuclear medicine physician. Conclusion: The exposure rate at surface of Patients is very high of 18F-FDG injected patients. Therefore the person administering the dose to patient should avoid standing very close to the patient. Also the half life of 18F is very less i.e. 109.7 minutes; therefore, exposure rate falls rapidly with the passage of time. So the exposure to staff and Nuclear medicine Physicians are very low