Establishment of a method for evaluating the performance of radiation-protective eyewear using a radiochromic film

This study aimed to evaluate the directional dependence of GAFCHROMIC LD-V1 (LD-V1) and assess its utility in evaluating the performance of radiation-protective eyewear. To evaluate directional dependence, a piece of LD-V1 was placed on the surface of a semicylindrical acrylic phantom and irradiated with X-rays at angles ranging from 0° to 90° with the perpendicular incidence on the orange polyester surface set to 0° and from 180° to 270° with the perpendicular incidence on the white polyester surface set to 180°. For the eyewear evaluation, six pieces of LD-V1 were placed on a head phantom, and the simulated patient phantom was irradiated for 1 h with and without radiation-protective eyewear at head orientations of 0° and 45° relative to the bed. The sensitivity at 0° was considered 100 %, and the relative sensitivity at 90° and 270° was 44.7 %. The radiation protection rates of the eyewear lenses were 58.7 % and 92.4 % for the right and left eyes, respectively, at 0°, and 80.9 % and 82.2 %, respectively, at 45°. The results demonstrate that LD-V1 is an effective method for evaluating radiation-protective eyewear performance, providing a detailed assessment of the lens radiation protection rate and dose distribution on the face. LD-V1 is suitable for dosimetry on curved surfaces, offering sufficiently accurate measurements as long as the X-ray beam is not parallel to the film surface, where sensitivity significantly drops. These findings suggest that LD-V1 is a valuable tool for practical radiation protection evaluation in clinical settings.