Brachytherapy, also called internal radiation to distinguish it from external beam radiation, is an alternative form of radiation therapy to treat malignancies. It delivers X-ray beams directly to the site of a tumor, placing radioactive material inside the body. This allows for a higher total dose of radiation over a shorter time frame than traditional radiation therapy. It also protects normal tissue from unnecessary exposure to radioactive material.
Reasons for Brachytherapy
Generally speaking, brachytherapy is most useful for cancers that are localized. Most commonly, brachytherapy is used to treat:
- Eye, head or neck cancer
- Lung cancer
- Gynecological cancer
- Brain cancer
- Esophageal, bile duct, or rectal cancer
- Breast cancer
- Anal or rectal cancer
- Skin cancer
This procedure is often performed in conjunction with other cancer treatments such as surgery or external radiation to ensure the complete removal of the cancerous tissue and a reduced risk of recurrence.
Benefits of Brachytherapy
There are many benefits to brachytherapy, depending on the priorities of the individual patient and the convictions of the individual doctor. In addition to protecting normal tissue by targeting malignant tissue more precisely, brachytherapy may offer one or more of the following advantages:
- Avoiding surgery
- Avoiding lengthy hospital stays
- Shortening recovery time
- Limiting risk of infection
- Causing fewer side effects
Because of the less invasive nature of the treatment and the decreased risk of side effects, more patients are willing to undergo brachytherapy than other forms of therapy.
The Brachytherapy Procedure
During a brachytherapy treatment, radioactive material is introduced into the body as near to the cancer as is practical. There are two means of inserting the radiation device into the body.
Into a Natural Body Cavity
During intracavity brachytherapy, a device containing radioactive material is inserted into a natural opening in the body, such as the windpipe, rectum, or vagina. The device may be inserted by a professional's trained and gloved hand or by a specially designed computerized machine.
Inside Body Tissue
This type of brachytherapy is known as interstitial radiation. During this procedure, wires, balloons, or tiny seeds may be inserted through catheters, needles, or other special applicators in order to disseminate radiation within body tissue. This technique is frequently used to treat breast or prostate cancer.
Whichever type of brachytherapy procedure is employed, imaging equipment, such as a CT scanner or ultrasound machine, may be used to guide instruments and ensure precise placement.
Types of Brachytherapy
There are two basic types of brachytherapy: high-dose-rate (HDR) and low-dose-rate (LDR).
High-dose-rate brachytherapy is administered on an outpatient basis, requiring just a few minutes to complete, and may be given several times a day over the course of a few weeks. HDR does not result in any pain and the patient, once the radioactive material is removed, does not give off any radiation. This means that a patient undergoing HDR does not present any danger to others and may carry on normal activities during treatment.
Low-Dose Rate Brachytherapy
Low-dose-rate brachytherapy is administered as continuous treatment over the course of several hours or days, delivering radiation in pulses. LDR sometimes requires an overnight stay in the hospital. Patients undergoing LDR, however, emit small amounts of radiation during treatment. Because there is a small chance that this radiation may harm others, children and pregnant women should not visit the patient during the treatment period, and other visitors should only have brief contact. Once the treatment is completed and the radioactive material is removed from the patient's body, visitors are no longer restricted.
In some cases, particularly with prostate cancer brachytherapy, the radioactive material remains in the patient's body permanently. Although at first the patient's body will emit low doses of radiation, the risk to others is considered minimal and visiting may not be restricted except, perhaps, for a short period of time, with children and pregnant women. The risk is considered to diminish over time, so restrictions will, at some point in the near future, be discontinued.