Evaluation of equivalent dose to working staff with oxygen-15-water in positron emission tomographic studies

With its short physical half-life and allowing for higher dosage injections , oxygen-15 labeled water has become increasingly important in many clinica l applications. However, the use of oxygen-15 labeled water could potential ly result in radiation exposures to working staff exceeding regulatory limi ts. In this study, thermoluminescent dosimeters (LiF-100H) were attached at various parts of the body to measure the accumulated equivalent doses of a physician and to evaluate the radiation risk to the sensitive organs which could receive as many as 10 intravenous injections of O-15-water for each subject studied. The results showed that during the injections, the hands o f a physician received the highest dose, which was about 25.8 times that of the routine chest X-ray dose. If protective shieldings were provided durin g injection, about 83% of the dose could be effectively reduced. Even witho ut any protective shielding, the estimated maximum dose to the physician wa s still within the regulatory limit, 50 mSv/year, suggested by ICRP 60. In conclusion, reducing excess radiation exposure to workers, by minimizing th e time spent in close contact with patients, increasing the distance from t he source and providing suitable protective shielding would be the most eff ective approach. (C) 2000 Elsevier Science Ltd. All rights reserved,