<b>Internal radiation therapy</b> allows a higher total dose of radiation in a shorter time than is possible with external treatment and places the radiation source as close as possible to the cancer cells. The radioactive material, sealed in a thin wire, catheter, or tube (implant), is placed directly into the affected tissue. This method of treatment concentrates the radiation on the cancer cells and lessens radiation damage to some of the normal tissue near the cancer.  Implants may be removed after a short time, or left in place permanently. The type of implant and the method of placing it depend upon the size and location of the tumor.
