Estimation of Eye Lens Dose during the Handling of Radiopharmaceuticals and Using X-ray Protective Goggles for Dose Reduction in Nuclear Medicine

Abstract

The purposes of this study were to estimate the eye lens dose during the handling of radiopharmaceuticals and to validate the requirement of X-ray protective goggles in nuclear medicine. Simulated eye lens radiation exposure (3-mm dose equivalent rate) was measured using a radiophotoluminescent glass dosimeter (RPLD) positioned at distances of 30 and 60 cm from 99mTc, 111In, and 123I radiation sources. Reduction rates were evaluated for the following means of radiation protection: X-ray protective goggles (0.07-, 0.50-, and 0.75-mm lead equivalent), a syringe shield, and a lead glass plate. 3-mm dose equivalent rates without protection were obtained at 6.13±0.13 µSv/min/GBq for 99mTc, 23.08±0.19 µSv/min/GBq for 111In, and 11.07±0.11 µSv/min/GBq for 123I. Reduction rates for each source were over 90% for the syringe shield and the lead glass plate. The 0.75-mm lead equivalent X-ray protective goggles decreased the 3-mm dose equivalent rate by 68.8% for 99mTc, 60.6% for 111In, and 68.1% for 123I. Although the estimated eye lens equivalent dose during the handling of radiopharmaceuticals did not exceed the threshold dose, our results suggest that 0.75-mm lead equivalent X-ray protective goggles are needed to reduce the exposure of the lens while handling 99mTc, 111In, and 123I radiation sources.