Investigation using an advanced extremity gamma instrumentation system of options for shielding the hand during the preparation and injection of radiopharmaceuticals

Abstract

Staff preparing and injecting radiopharmaceuticals in hospitals may receive significant radiation doses to their hands. These doses may be high enough to warrant that they be classified as radiation workers. The influence of local shielding on finger doses has been investigated. Staff preparing radioactive liquids in a radionuclide dispensary and drawing up and injecting radiopharmaceuticals in a nuclear medicine department have been studied. Measurements have been recorded with an electronic extremity dose monitor, an advanced extremity gamma instrumentation system (AEGIS), worn near to the finger tip. The electronic dosimeter allows the pattern of doses received during different procedures to be determined. Doses received for individual manipulations during many routine sessions have been recorded for different staff members. Dose distributions around shielded vials and syringes have also been measured using AEGIS. In the radionuclide dispensary the vials from which radioactive liquids are dispensed are held in tungsten shields, whereas in nuclear medicine simple lead pots are used. Syringe shields are employed for some parts of dispensing and patient injections. Data on dose distributions have been used in interpretation of results from monitoring. Use of syringe shields during dispensing reduced the finger dose by 75-85%. The peaks in dose rate were 60% lower, and periods of exposure to high dose rates were reduced in length by a third because of the restriction in the region of high dose rate. The extremity doses to staff dispensing and injecting radiopharmaceuticals in nuclear medicine were of similar magnitude. Doses received during dispensing varied from 10 to 555 microGy depending upon whether the vial containing the radiopharmaceutical was directly handled or not. Dose received from individual injections varied from 1 to 150 microGy depending on the degree of difficulty experienced during the injection.