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

Purpose: 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.

Method: 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 Tc, In, and I 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.

Result: 3-mm dose equivalent rates without protection were obtained at 6.13±0.13 µSv/min/GBq for Tc, 23.08±0.19 µSv/min/GBq for In, and 11.07±0.11 µSv/min/GBq for I. 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 Tc, 60.6% for In, and 68.1% for I.

Conclusion: 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 Tc, In, and I radiation sources.