Efficacy of aprons equivalent to 0.5 mm of lead in PET procedures using the Monte Carlo

Abstract

In Positron Emission Tomography (PET), health staff is exposed to 511-keV photons, which is a result ofthe positron annihilation process. This energy is about four times greater than the 140 keV commonlyfound in studies based on Single Photon Emission Computed Tomography (SPECT). Besides thisdifferent level of energy, 0.5 mm lead-equivalent aprons have being used either in SPECT or PETprocedures. In this context, this work was designed for evaluating the effectiveness of such aprons inindividual radioprotection of health professionals involved in Positron Emission Tomography. For this,by using MCNP4C-based Monte Carlo simulations, the average energy delivered per particle to theregions corresponding to operational quantities Hp(10) and Hp(0.07) were calculated for two conditionsof individual exposures: wearing and not wearing a 0.05 mm lead-equivalent apron. The results obtainedpointed out that Hp(10) has similar value in both situations. On the other hand, for the regioncorresponding to Hp(0.07), wearing this lead apron will improve this dose in about 26%. On the basis ofthis work, 0.5 mm lead equivalent aprons do not offer adequate protection for medical staff working onPositron Emission Tomography.