Brachytherapy is a type of radiation treatment where the source of radiation is implanted into the patient as close to the cancer as possible. The radiation is delivered to the tumor site with radioactive isotopes contained within wires, seeds, or rods. Brachytherapy allows for a higher total dose of radiation over a shorter period of time than does external beam therapy. The radiation dose is concentrated on the cancer cells, resulting in less damage to the normal cells near the cancerous growth.
Brachytherapy implant placement may be permanent or temporary. Permanent brachytherapy, also called low dose rate brachytherapy, uses implants called pellets or seeds. These implants are very small, about the size of a grain of rice. The implants are inserted directly into a tumor through thin, hollow needles. The implants are left in place after the radiation has been used up, as their small size causes little or no discomfort.
In temporary brachytherapy, implants such as hollow needles, catheters (hollow tubes), or balloons filled with fluid, are inserted into or near the cancer for a period of time, then removed. Either high-dose or low-dose brachytherapy may be used.