Measurement of radiation levels and staff safety in the PET/BT centre

In this study, the aim was to determine the radiotion doses received by staff in Celal Bayar University Hospital PET-CT (Positron Emission Tomography/Computed Tomography) using TLD (thermoluminescent dosimeter-TLD100) and ED (electronic dosimeter). Doses of all bodies, eyes,thyroids and hands (hand is the most exposed to radiation) of each staff was measured using TLD100. The routine works of the staff are classified as preparing FDG (setting patient dose and carrying patient dose), injection of F-18 FDG (Fluorodeoxyglucose) and monitoring patient. Elapsed time in each process was registered. For each of these process, calibrated TLDs is placed to all body, eye, thyroid and fingers of the staff. Dosimeters were annealed for 1 hour at 400 ºC and 2 hours at 100ºC before use. TL glow curves of the dosimeters were registered from 50 to 350 º C with a heating rate of 2ºC/s in Harshaw TLD 3500 reader, and the radiation doses were calculated. In addition, TLD dosimeters were placed to distances of 0.25. 0.5, 1.00 m from patients in order to assess the scattered radiation doses resulted from CT (Computed Tomography) room. In this case, the monthly and annual radiation doses received by the personnel were determined. Results obtained from the current study were showed that the highest radiation doses were received by the hands of the personnel who were exposed the radiation for longest time. The doses received by the right and left hands of the personnel applying injection were assessed to be 1.7 mGy and 2.36 mGy, respectively. Similarly, the dose received by the right and left hands of technician were measured as 8.8 mGy and 6.04 mGy, respectively. The lowest radiation doses were determined as 0.29mGy for all body, 0.32 mGy for thyroid during injection and 0.36 mGy for thyroid while in the laboratory.