Radiation safety in the central radiopharmacy

Abstract

The currently increasing number of new radiopharmaceuticals and the increase in individual patient-dose activity, particularly for single photon emission computer tomography imaging, coupled with the switch toward unit doses probably contribute to an increase in the radiation burden to radiopharmacy personnel. To meet this increased need of the nuclear medicine community, a medium-sized radiopharmacy may order seven to eight 3-Ci molybdenum-99/technetium-99M generators per week and may perform 10 to 15 elutions per day. The maximum radiation exposure to radiopharmacy personnel occurs during the generator elutions, compounding (kit preparation), and unit-dose dispensing. Additional sources of radiation exposure can occur during receipt of radioactive packages, transport of prepared doses, and the process of storage and disposal of radioactive waste. Recent reports have shown extremity radiation doses to the fingers and hands at 14 to 21 rem/year. Radiation exposure can be monitored by film badges, thermoluminescent detectors, or one of the analog or digital self-reading dosimeters. Each monitoring device has advantages and the choice depends upon the personnel involved (eg, visitors) and the particular needs of the radiopharmacy. Extremity dose reductions during radiopharmacy procedures can be achieved by a number of techniques, some as simple as the use of 8- to 9-inch forceps during transfers of radioactive vials and syringes and the use of a dose-drawing syringe shield during unit-dose dispensing procedures. In preparation of unsealed doses or capsules of radioactive iodine, there is a potential for a high internal dose because of inhalation of the volitile solution. Frequent monitoring in the form of bioassays and the use of strict threshold levels will ensure early detection of exposure to radioactive iodine and quick corrective action. In pharmacies and nuclear medicine departments handling fluorine-18 for use with Anger gamma cameras, the high levels of both beta and gamma radiation present an additional set of radiation safety problems.