Internal radiation therapy, also called brachytherapy or seed implantation, is a type of radiation therapy in which radioactive materials are placed inside the affected area, either temporarily or permanently. This therapy delivers a high dose of radiation directly to the cancerous area. The seeds give off their radiation slowly over several months and within one year, their radiation completely decays. The seeds can remain safely in place for the rest of the patient's life. Internal radiation therapy is most often used to treat head and neck, prostate, cervix, ovary, breast, and perianal and pelvic cancers. Depending on the form of cancer, the radioactive material (called "seeds") may be directly injected, or the material can be put in a sealed plastic container (called an "implant").
A surgeon and radiation oncologist usually work together to perform the implant. While the details of procedure depend on the location of the cancer, the surgeon is responsible for planning the insertion of the radioactive material into the body, or for setting up a temporary guide which is used when seeds are injected. The radiation oncologist prepares, and in some cases, implants the radioactive material. Most patients are discharged three to four hours after the implant procedure, although inpatient stays may be required.
There are a number of reasons to use internal radiation therapy instead of external. For some patients, the procedure causes fewer side effects than external options. It is often used to provide a "booster dose" to minimize risk of reoccurrence after treatment, or to provide a steady dose of radiation to the affected area. It can also be a more convenient alternative to external radiation therapy, in that only one visit is required.
HDR brachytherapy is a form of internal radiotherapy where a catheter (a small plastic tube or balloon) is temporarily implanted in the tumor area. Highly radioactive material is then placed inside the body for a short period of time. Multiple sessions may take place, at the end of which the catheter is removed. HDR brachytherapy is most commonly used with cancers located near the outside of the body.
Specific information on HDR brachytherapy procedures is available for:
