Brachytherapy, also called internal radiation therapy, is a procedure in which a radiation source is placed inside the body to treat cancer, according to the Mayo Clinic. Brachytherapy allows the physician to expose the cancerous cells to radiation without exposing healthy cells in other parts of the body. Furthermore, the Mayo Clinic reports that brachytherapy may cause fewer side effects, and allow a shorter treatment time. There are three main types of brachytherapy, named based on the level of radiation and details of implantation.
Low-Dose Rate Implant Brachytherapy
In brachytherapy that involves low-dose rate, or LDR, implants, the radiation sources are implanted for a few hours up to seven days, according to the National Cancer Institute (NCI). The American Cancer Institute notes that the patient may be able to go home during this period or may be required to stay in the hospital, depending on the size of the implant, and where it has been placed. The NCI notes that the doctor may limit visitation during this period, but once the implant is removed, the body is no longer emitting radioactivity, and the patient can immediately be around other people again.
High-Dose Rate Implant Brachytherapy
The American Cancer Institute reports that brachytherapy with high-dose rate, or HDR, implants allows for a treatment time of only a few minutes. For this type of brachytherapy, the very powerful HDR implant is placed in an applicator and put into position near the cancerous cells. Though the actual treatment time is only a few minutes, after which the radiation source is removed, the procedure may be repeated on a few separate occasions. During the time between procedures, the applicator may be left in place.
Permanent Implant Brachytherapy
For the treatment of prostate cancer and occasionally lung cancer, brachytherapy may involve the permanent implantation of a radiation source. Permanent implants are often referred to as "seeds," which are the size of a grain of rice, and side effects from this type of implant are quite rare. These permanent implants are self-limiting, and stop giving off radiation after a certain amount of time, usually a few weeks.
