Assessment of extremity exposure to technologists working manually with 99m Tc-labelled radiopharmaceuticals and with an automatic injection system for 18 F-FDG.

The hands of nuclear medicine (NM) personnel involved in radiopharmaceutical preparation and administration can receive significant radiation doses. The dose distribution across the hand is nonuniform and the Hp(0.07) doses obtained by an individual passive ring dosimeter do not always present a real situation. The aim of this study was to assess the extremity exposure of NM workers working with 99m Tc-labelled radiopharmaceuticals and with an automatic IRIDE (COMECER, Italy) 18 F-FDG injection system. Hp(0.07) doses were measured using calibrated thermoluminescent dosimeters-100 (TLD-100) and were read by a RIALTO TLD (NE Technology) reader. It was found that the most exposed parts of the hand during work with 18 F and 99m Tc radionuclides are the fingertips of the thumb, index finger and middle finger. The maximum fingertip doses were 1.3-2.4 times higher compared with the doses from the typical monitoring position (base of the middle finger of the dominant hand). When working with 99m Tc, the average hand doses were relatively high, i.e. 0.17 ± 0.04 and 0.37 ± 0.13 mSv Gbq -1 for the left and the right hand, respectively, during preparation, and 58 ± 20 and 53 ± 13 µ Sv GBq -1 for the left and the right hand, respectively, during administration of 99m Tc labelled radiopharmaceuticals. Meanwhile, the lowest doses were found for hands during administration of 18 F-FDG (average hand dose 28 ± 13 µ Sv GBq -1 for the left hand and 28 ± 7 µ Sv GBq -1 for the right hand), which shows the advantages of automated injection/infusion systems, thus implementation of automatic infusion/injection in hospitals could be an expedient way to optimize Hp(0.07) doses to NM workers.