Active Personal Dosimeter in a Nuclear Medicine Center in Yazd City, Iran

Introduction: Active personal dosimeters (APDs) are well accepted as useful and reliable instruments for individual dosimetry measurements. APDs have many advantages compared with passive dosimeters for individual external radiation dose assessments. In routine monitoring, occupational exposure is carried out for verification and demonstration of compliance with the regulatory dose limits. So, it is one of the most important tools in order to achieve or demonstrate the level of radiation protection. Methods: Yazd province has only one private nuclear medicine (NM) center. In this center, two NM technologists exposed to radioactive patients during radiopharmacuticals preparation were monitored. NM technologists have to be close to the patient during radiopharmaceutical injection and patient positioning on the gamma camera table. An electronic personal dosimeter DKG-21 Ecotest made in Ukraine which records the ambient dose equivalent rate and equivalent dose was used to monitor the radiation exposure to the technologists and to record the accumulation dose in mSv throughout a working day. This study was accomplished between the time period of January to June 2011. The dosimeter is designed to measure individual equivalent dose Hp(10). The dose range of gamma radiation was 0.01 mSv to 1 Sv and the energy range 0.05 to 6 MeV which was suitable for NM procedures. The planar and tomography NM images were performed by the 2 technologists in the morning and afternoon shifts. Results: The average monthly occupational dose of each technologist was approximately 0.6 mSv. Their annual doses were 6.6 and 8.8 mSv, respectively. They were lower than the maximum permissible dose of 20 mSv/y. Total number of NM procedures performed in this NM center during June 2010 to June 2011 was 3265. Conclusion: The use of APD for monitoring the NM technologists is a useful tool to check compliance with regulatory dose limits and radiation protection principals.