internal radiation therapy
(in-TER-nul RAY-dee-AY-shun THAYR-uh-pee)
A type of radiation therapy in which a source of radiation is put inside the body. Brachytherapy is a type internal radiation therapy that involves placing radioactive implants, such as pellets, seeds, ribbons, wires, needles, balloons, or capsules, in the body, directly into or near the tumor. Systemic radiation therapy is a type of internal radiation therapy that uses a source of radiation that is swallowed or injected into the body and travels through the blood, finding and killing tumor cells throughout the body.