Finger doses received during 18FDG injections calculated with Monte Carlo simulations

The main objective of this work is to evaluate the absorbed doses in the fingers of PET physicians derived from the administration of ¹⁸FDG, using the Geant3 Monte Carlo code. A comparison is made with data obtained with thermoluminiscent dosimeters. The administration of a PET radiopharmaceutical such as ¹⁸FDG presents a radiation hazard to the hands and fingers. One motivation for this study is the increased use of PET imaging in nuclear medicine that was not followed by a parallel development in the respective dose measurements and optimisation. Considering a workload of 10 patients per week, each medical doctor receives finger doses 3 times lower than the weekly skin dose limit with the fingers in the active volume and 10 times lower if they are in the rear end of the syringe. In the calculations it is assumed that a typical administered activity is 0.185 GBq with a finger-syringe contact time of 10 s. Monte Carlo calculations were performed for different kinds of syringes and different injected volumes. We have also calculated finger doses as a function of the wall thickness for three kinds of wall materials. Results show a slight dose reduction when the polypropylene syringe is replaced by a pyrex one and could be used to derive guidelines for the handling of syringes containing the most used PET radiopharmaceuticals.