What are the types of radiation therapy?

There are two main types of radiation therapy: external beam and internal. According to the National Cancer Institute, external beam radiation therapy comes from a machine that aims radiation at your cancer. The machine is large and may be noisy, but it does not touch you — it can move around you, sending radiation from many directions. It is a local treatment, meaning it treats a specific part of your body.

Internal radiation therapy places a source of radiation inside your body, and the source can be solid or liquid. A solid source is called brachytherapy, in which seeds, ribbons, or capsules are placed in or near the tumor; like external beam radiation, this is a local treatment. A liquid source is a form of systemic therapy, meaning it travels in the blood to tissues throughout your body.

Which type you have depends on many factors, including the type, size, and location of the tumor. Your healthcare team can explain the best option for your cancer.