Staff dose at different body regions and at different stages of 18F-FDG PET/CT procedures

Abstract

Purpose Personnel monitoring results provide information on routine radiation exposure, assist in work planning and allow control of the workplace. The FDG PET/CT applications have been continuously increasing for diagnostic procedures. Although such an increase is a positive trend for the benefit of patients, the associated risk of radiation exposure of staff needs to be properly evaluated. The aims of this study were to estimate the effective dose for the staff at different body regions and at different stages of the PET/CT procedure. Method To estimate the effective dose from external exposure, all 6 members of the staff (2 nurses, 2 medical physicists, 2 technologists) had TLD badges worn at the upper pocket of their overall and digital dosimeters worn at the side pocket. High sensitivity thermolumiscent dosimeters were used. The measurements that were made include 5 different body regions: eye, thyroid, gonads, fingers and body at all stages of the PET/CT procedure: dose segmentation, injection of the radiopharmaceutical, handling the patient and positioning the patient. Results Results show that the mean effective dose received by each member of the staff was approximately 12.32 μSv and the mean daily dose/MBq was about 0.03 μSv. All statistical tests show no significant differences between the results for eye, thyroid and body. The staff dose received in at gonads is found to be statistical significant lower when compared to the body dose. About 57% of the staff dose resulted from patient interaction. The maximum doses to fingers were during the segmentation of radiopharmaceutical and the maximum whole body dose was during the injection of the FDG. Conclusion The personnel dose results are significantly lower than the recommended annual dose by International Commission for Radiological Protection. However a greater effort should be made to reduce the doses further in line with the ALARA principle.