Authors (including presenting author) :
Li KW
Affiliation :
Department of Clinical Oncology, Tuen Mun Hospital
Introduction :
Lead apron has long been used for protection against scattered radiation during interventional procedures. It contains core materials with radiation attenuation capabilities embedded in the outer fabric. In the past, the core material was powdered lead in a flexible polymer matrix. Since lead is heavy and toxic, lightweight lead-free lead aprons have appeared in recent decades in order to mitigate the work-related musculoskeletal problems and disposal issues. However, can these aprons offer the same level of protection as the traditional pure lead aprons?
Objectives :
To test the shielding effectiveness of the lead-free lead aprons that are commonly used in New Territories West Cluster (NTWC).
Methodology :
Two types of lead-free lead aprons produced by two different manufacturers, Prestige 0.5mm (Bar-Ray Products) and Kiarmor bi-layer lead-free 0.5mm (Infab Corporation), were tested using an in-house broad beam measurement geometry which was similar to the inverse broad beam geometry used in IEC 61331-1:2014 and DIN 6857-1. The apron being tested was placed at 0.8 m from the focal spot of a DX-D600 digital radiography system (Agfa HealthCare). The x-ray beam was collimated such that the field size on the apron was 30 cm x 30 cm. A solid-state detector was placed on the table at 0.2 m behind the apron. The total filtration of the x-ray tube was 3.5 mmAl. The beam qualities were measured in terms of half-value layer (HVL) at each kVp. The transmission percentage of the apron was calculated from 50 to 130 kVp.
Result & Outcome :
Kiarmor allows at most 8% transmission (92% attenuation) of radiation at 130 kVp, while Prestige allows at most 10% transmission (90% attenuation) of radiation at 130 kVp. The difference is due to the difference in the core materials used between them. Kiarmor contains a mixture of Antimony and Bismuth, while Prestige contains a mixture of Antimony and Plastisol. Bismuth helps absorbing the photons created by the fluorescence of Antimony, thereby reducing the absorbed dose to the apron wearer. The testing results can be used as a guide to choose the proper radiation protection garment in our work scenarios to achieve the ALARA radiation safety principle.
