Monte Carlo simulation of eye lens dose and shielding effectiveness for radiation workers in nuclear medicine

The aim of this work was to estimate the eye lens dose equivalent at a depth of 3 mm and to evaluate the effectiveness of shielding for radiation workers in nuclear medicine using Monte Carlo simulation with the Monte Carlo N-Particle transport code, version 5. Published air kerma rate constants were used to validate the simulation code for commonly used radionuclides in nuclear medicine, including ¹⁸F , ⁹⁹ᵐTc , and ¹³¹I . Eye lens dose rates with commercially available syringe shields and vial shields were simulated using the Monte Carlo N-Particle code with the Posture, Individual, and Medical Application Laboratory phantom. Shielded and unshielded eye lens dose rates based on commercially available source data were simulated for common radionuclides at various distances. The maximum number of procedures was also estimated based on the eye lens dose limit recommended by the International Commission on Radiological Protection publication 118. The simulated dose rates may be used to evaluate radiation safety considerations for workers in nuclear medicine. Appropriate shielding and eye lens monitoring are particularly recommended for positron-emitting ¹⁸F and high-activity ¹³¹I procedures.