Evaluation of Equivalent Dose to Technologist's Hands during the Preparation of Radiopharmaceuticals

Abstract

In Thailand, the diagnostic and therapeutic uses of radiopharmaceutical preparations in nuclear-medicine centers are increasing every year. Workers preparing or administering radiopharmaceuticals are at risk of receiving high equivalent radiation doses to their hands. To date, no research has determined radiation doses among these groups of workers. This study aimed to measure radiation equivalent doses to workers' hands while preparing radiopharmaceuticals, using a thermoluminescence dosimeter (TLD), and to compare doses with those not involved in these tasks. Twelve nuclear medicine centers participated, with 19 and 13 persons in the test and control groups, respectively. TLD rings were worn on both thumbs for 2 periods of 2 consecutive weeks. The results showed that 18 persons in the test group (95%) received radiation equivalent doses of between 5.6 and 263.7 mSv/y. The average dose was 68.0+63.0 mSv/y. These results were within the 500 mSv/y dose limit recommended by ICRP 60. Variations in the dose received ranged from 1 to 52.7% of the dose limit, and resulted from different workloads among centers and radionuclide sources available at the center, e.g. a radionuclide generator or unit doses. In the control group, no radiation doses were detected in 11 persons (85%). A comparison of the two groups found that the preparation group received higher equivalent doses to the hands than the control group. The differences in doses received between the two groups were statistically significant (P =0.0004). This study, although undertaken within a short period of time, represents their working conditions and activities. The results can be used to inform the planning of protective measures compliant with the "as low as reasonably achievable" (ALARA) principle, and increasing the awareness and understanding of the importance of radiation safety standards in nuclear medicine in Thailand and elsewhere.