Assessment of the Effect of Nano-Composite Shield on Radiation Risk Prevention to Breast During Computed Tomography

Abstract

Background: Application of nanomaterial has recently been introduced as a novel method to make a radiation shield to protect biological damage. Objectives: The purpose of this study was to evaluate the effectiveness regarding the use of nano-shield on the protection of the breast in chest computed tomography (CT) scan. Materials and Methods: Bismuth oxide nanoparticles were prepared and synthesized in the Chemistry Laboratory of the University of Tabriz. Special tests were used to evaluate the properties of nanoparticles. Then, nano-bismuth oxide shields were designed with the silicon matrix at 10% and 15% ratios in 0.5- and 1-mm thicknesses, respectively. The dosimetry process was performed by thermoluminescent dosimeters (TLD) dosimeters in the skin and fourth layers of the breast in the chest CT scan. Also, signals and noises of the images were obtained to assess the effects of shield on image quality. Nanoparticles size was equal to 24 nm and they were spherical in shape. The distribution of nanoparticles in the silicone matrix was approved by scanning electron microscope energy dispersive spectroscopy (SEM-EDS). Results: Nano-bismuth shields reduced the dose value by 9% and 15% in the skin layer related to 10% and 15% bismuth nanoparticles ratio (0.5 mm thickness), respectively. Also, by increasing shield thickness to 1 mm, the dose of skin layer was reduced by 18% and 24% related to 10% and 15% of bismuth nanoparticles ratio, respectively. Analysis of CT image showed a 10% increase in the noise related to the 10% bismuth shield. Conclusion: The nano-bismuth composite shield with different ratios and thicknesses show significant dose reduction in the breast. This could play a role in breast cancer prevention during chest CT scan.