What is the typical diameter of a teletherapy source?

The typical diameter of a teletherapy source, specifically for common high-energy radiation sources like cobalt-60 or cesium-137, is generally around 2 cm. This dimension is relevant because it helps define the geometry and characteristics of the radiation beam produced. Most teletherapy sources are designed to deliver a uniform radiation dose over a specific area, and the diameter impacts how the radiation spreads and the dosimetric properties.

When administering high-energy radiation treatments, the source's size is critical in ensuring that the treatment area receives the correct dose while minimizing exposure to surrounding healthy tissue. A source that is too small may not effectively cover the tumor volume, while a source that is too large could increase unnecessary dose to healthy structures.

In the context of dosimetry and qualified treatment planning, understanding the physical properties of the teletherapy source, including its size, allows practitioners to better calculate dose distributions, establish treatment protocols, and optimize radiation delivery methods.