A new radiation shielding block material for radiation therapy.

In recent years, lead has been recognized as a source of environmental pollution; this includes lead use for radiation shielding in radiotherapy. We looked for a new material that could be a lead substitute. We chose a material composed of tungsten and resin. We compared the attenuation coefficient of the material with those of lead and Lipowitz's metal, and found the material has a higher attenuation coefficient than the other two. The material may be used as a substitute for lead because it is easy to fabricate and friendly to the environment.