Brachytherapy (also known as internal radiation) involves placing a small radioactive source (pellet or seed) inside the body near the tumour. It allows higher doses of radiation to be given to specific areas of the body, and may cause fewer side effects than conventional radiation therapy. With brachytherapy, treatment time is usually shorter.
The brachytherapy seeds may be placed inside a body cavity, like the vagina, or inserted into the tissues using hollow needles. They may be left in permanently or removed after some time.