What is one of the primary functions of a wedge filter in radiation therapy?

A wedge filter in radiation therapy is primarily used to modify the intensity distribution of the radiation beam delivered to the treatment area. By incorporating a wedge filter into the beam, the filter is designed to gradually attenuate the intensity of the radiation from one side of the field to the other. This creates a sloped dose distribution that can help achieve more uniform dose coverage, particularly in areas where there is a geometric irregularity or when treating tumors that have differing depths.

This ability to reduce beam intensity enhances target coverage while minimizing dose to surrounding healthy tissues. It allows for more precise dose optimization, particularly in treatments for irregularly shaped tumors or areas where the anatomy varies significantly. The use of wedge filters is particularly valuable in the context of certain treatment techniques, such as tangential breast irradiation or with other situations where a uniform dose distribution is desired despite anatomical challenges.

The other options describe functions that wedge filters do not fulfill. They do not increase beam intensity, alter beam angles, or focus the X-ray beam, which are characteristics of other components or techniques used in radiation therapy. Therefore, the option regarding the reduction of beam intensity accurately reflects the primary role of a wedge filter in radiation treatment planning and delivery.