Radiation therapy commonly is used after lumpectomy to treat early-stage breast cancer and reduce the risk of the cancer coming back (recurrence). Brachytherapy is a newer form of radiation therapy and an alternative to external beam radiation therapy.
Brachytherapy delivers a higher dose of radiation to a smaller area of the breast over a shorter period of time than traditional (external beam) radiation therapy. A study found that brachytherapy use has been increasing steadily since it was first approved by the U.S. Food and Drug Administration in 2002. The researchers are concerned about this increase in brachytherapy use because there aren't many long-term studies that show that brachytherapy works as well as traditional radiation therapy.
Traditional external beam radiation therapy aims cancer-destroying energy at the whole breast or to the area of the breast where the cancer was. The source of the radiation is outside the breast, which is why it's called "external beam." Many studies have shown the long- and short-term effectiveness of external beam radiation therapy. The drawbacks of traditional radiation therapy include daily trips to the hospital for treatments -- typically 5 days a week for 4 to 6 weeks. Traditional radiation therapy also has a large field and may expose healthy tissue, such as the heart and lungs, to radiation.
To overcome the drawbacks of traditional radiation therapy, doctors have developed different ways to deliver radiation. Brachytherapy places the radiation source inside the breast. Two types of brachytherapy are used right now:
- Multi-catheter internal radiation uses radioactive "seeds" to deliver radiation directly to the area where the cancer was. The seeds are placed in very small tubes called catheters that are stitched into place under the skin. The seeds are left in the catheters for a few hours or a few days. You remain in the hospital during treatment. Once the treatment is completed, the seeds, catheters, and stitches are removed and you go home.
- Balloon internal radiation (brand name: MammoSite) uses a special catheter with a balloon on the end that's placed in the breast where the cancer was. The catheter, which comes out of the skin, and balloon are placed either during lumpectomy or afterward, in a surgeon's office. For each treatment, a machine places a radioactive seed into the center of the balloon for up to 10 minutes. After the seed is removed, you're free to leave the treatment center between treatments. Treatments are usually given twice per day for 5 days. When the final treatment is done, the balloon and catheter are removed.
In this study, researchers looked at the medical records of nearly 7,000 women age 65 or older who were diagnosed with breast cancer between 2001 and 2006. Almost all of the women were diagnosed with early-stage breast cancer, although a few of the women were diagnosed with metastatic breast cancer. All of the women had lumpectomy followed by some type of radiation therapy:
- 95% had traditional external beam radiation
- 5% had brachytherapy
Even though overall only 5% of all the women had brachytherapy, as time went on, more women chose brachytherapy. Looking at the women's radiation choices by year:
- from 2001 to the middle of 2002 (when one type of brachytherapy was approved by the FDA), only 1% of women had brachytherapy
- from the second half of 2002 to the middle of 2004, 3% of women had brachytherapy
- in the second half of 2004 (when Medicare started to pay for brachytherapy), 4% of women had brachytherapy
- in the first half of 2005, 6% had brachytherapy
- in the second half of 2005, 8% had brachytherapy
- in the first half of 2006, 10% had brachytherapy
Several medical and non-medical factors seem to be linked to a woman choosing brachytherapy over external beam radiation therapy, including:
- cancer that hadn't spread to the lymph nodes
- receiving treatment in the western United States compared to the Northeast
Even though brachytherapy is becoming a more popular radiation therapy choice, the researchers pointed out that right now there's limited evidence that brachytherapy is effective over a long period of time. Still, brachytherapy's safety and effectiveness are being studied and the results so far have been reassuring. Besides being a quicker way to deliver radiation therapy, many doctors like brachytherapy because the radiation is delivered in a focused manner, potentially avoiding exposing healthy tissue to radiation.
If you'll be receiving radiation therapy after lumpectomy, you and your doctor may consider brachytherapy as an alternative to traditional external beam radiation therapy. Perhaps the daily trips to the treatment center would be a burden because of distance. Talk to your doctors about their experience with brachytherapy compared to traditional radiation therapy. You also may want to ask about their familiarity with the technical aspects of delivering brachytherapy since placement of the catheters or balloon is a skill that can take some time to master.
The Breastcancer.org Radiation Therapy section has more information on both traditional external beam radiation therapy and brachytherapy.