Ages 14-18: Educational Resources
Radiation therapy
Radiation therapy is most often used to treat cancer. It does this with high-energy radiation beams that damage cancer cells and stop them from growing.
Radiation therapy can be done externally (outside the patient’s body) and internally (inside the patient’s body).
External treatment, called teletherapy, uses radiation beams administered from a distance from the body. The radiation beams are created using radioactive sources or linear accelerators, machines that produce beams of ionizing radiation.

Internal radiation therapy, called brachytherapy, involves implants of small radioactive sources inserted in or close to the part of the body affected by cancer.
Did you know? Doctors that specialize in treating cancers are called oncologists.