Brachytherapy, also known as seed implant or radioactive seed implant, is a form of internal radiation therapy. Radioactive material contained in tiny seeds, smaller than a grain of rice,is placed directly into or near the tumor. This enables the doctor to give a higher, concentrated dose of radiation in a shorter time than is possible with external treatment while sparing the surrounding healthy tissue.

 
Brachytherapy is often used for cancers of the head and neck, breast, uterus, thyroid, cervix, and prostate. A combination of internal and external radiation therapy may be used.

Brachytherapy is usually performed on an outpatient procedure. The procedure is completed in approximately one hour. The seeds remain in the body and give off radiation for about one year.