What is brachytherapy?
Brachytherapy is the use of radioactive sources placed inside a patient’s body in order to kill cancer cells. The word comes from a combination of two Greek words, brachy (short distance) and therapy (treatment). A number of different types of cancer may be treated using this method, including prostate cancer, cervical cancer, and endometrial cancer, as well as others throughout the body.
The advantage of brachytherapy is its use of a higher dose of radiation in a more targeted area, and in a shorter period of time, than is possible with a beam of radiation delivered from outside the body. The radioactive source, which is placed next to or inside a tumor, destroys the DNA (genetic material) of cancer cells and prevents them from growing and dividing.
What are the different types of brachytherapy?
- Temporary: Radioactive material is placed inside a catheter (a narrow tube that can be inserted into a body cavity such as the rectum, vagina, uterus, or inside the tumor itself) for a specific amount of time, then taken out.
- High-dose rate (HDR): A high dose of radiation for a short period of time, about 10-20 minutes per session.
- Low-dose rate (LDR): A low dose of radiation delivered over a long period of time, about 20-50 hours.
- Pulsed-dose rate (PDR): Radiation is delivered in a regular pattern (usually once per hour) rather than continuously.
- Permanent or permanent LDR: Also known as seed implantation. Radioactive seeds or pellets smaller than a grain of rice are placed in or near the tumor and left there permanently. After a number of months the seeds will lose their radioactivity but they can be left in the body with no harm to the patient. In addition to seeds, other methods of delivery are ribbons, wires, needles, capsules, balloons, or tubes.