Evaluation of Annual Occupational Doses of Technologists in Diagnostic Nuclear Medicine

Objective: This study aimed to determine the radiation dose contribution of radiopharmaceuticals labeled with 99mTc, 18F and 68Ga to the technologists' annual occupational doses over 6 years. Methods: The scintigraphic examinations were subdivided into 6 groups: (i) positron emission tomography/computed tomography (fluorine-18 fluorodeoxyglucose and Gallium-68 prostate-specific membrane antigen/Dotatate), (ii) positron emission tomography/Magnetic Resonance, (iii) singlephoton emission computerized tomography/computerized tomography, (iv) single-photon emission computerized tomography, (v) thyroid scintigraphy and uptake, and (vi) dual-energy x-ray absorptiometry. A total of 19 technologists worked in the period between 2016 and 2021, and the corresponding personnel dosimeter records were evaluated retrospectively. The annual number of scintigraphic examinations and annual occupational doses to which the technologists were exposed as well as the absorbed doses per procedure were yielded in microsievert ([mu]Sv) for the working technologists. Results: Annual occupational dose values and dose per exam were found to be 4.6 [+ or -] 2 mSv and 4.67 [+ or -] 1.75 [micro]Sv in positron emission tomography/ computed tomography, 1.434 [+ or -] 0.249 mSv and 3.64 [+ or -] 0.76 [micro]Sv in positron emission tomography/Manetic Resonance MR scans, 2.008 [+ or -] 0.3 mSv and 0.98 [+ or -] 0.07 [micro]Sv in single-photon emission computerized tomography/computerized tomography scans, 1.478 [+ or -] 0.386 mSv and 0.63 [+ or -] 0.24 [micro]Sv in single-photon emission computerized tomography scans, 1.710 [+ or -] 0.154 mSv and 0.59 [+ or -] 0.06 [micro]Sv in thyroid scintigraphy and uptake measurements, and 0.334 [+ or -] 0.221 mSv and 0.052 [+ or -] 0.027 [micro]Sv in dual energy x-ray absorptiometry scans. Conclusion: The dose contribution of positron emission tomography/computed tomography is the highest among the nuclear procedures conducted for diagnostic purposes. Our analysis highlighted that the workload of imaging technologists should be limited to 10 patients per day in positron emission tomography/computed tomography involving the routine tasks of activity preparation, injection, patient positioning, and patient discharge. Keywords: Technologist doses, radiation doses, PET/CT staff doses