Brachytherapy: Targeted Breast Cancer Treatment Comes With Risks
An increasing number of women are treating their breast cancer with brachytherapy, a type of radiation therapy that delivers a smaller, more targeted dose of radiation.
But a new study suggests that the treatment might increase the likelihood that a woman’s breast would need to be removed, and that the therapy may cause more complications after treatment.
Doctors say the findings don’t condemn the treatment but do give doctors and patients something to think about when selecting appropriate treatments for breast cancer.
Researchers from M.D. Anderson Cancer Center in Houston studied the Medicare records of more than 92,000 women age 67 and older whose invasive breast cancer had been treated with a lumpectomy and a subsequent course of radiation. Of those women, almost 86,000 received whole-breast irradiation and nearly 7,000 received brachytherapy.
When it came to survival after breast cancer, there was no difference between the two groups. But women who received brachytherapy were more likely to need a mastectomy within five years of their treatment. Four percent of the women who got brachytherapy got a mastectomy within five years compared with 2 percent of women who received whole-breast irradiation.
Women who received brachytherapy also had more complications, such as breast pain and rib fractures, after treatment.
Dr. Ben Smith, the study’s author and an assistant professor of radiation oncology at M.D. Anderson, acknowledged the difference in mastectomy rates between the two groups was slight, but said the data gave the best information so far on the differences.
What are the advantages of high dose rate (HDR) Brachytherapy?
- Short course of treatment compared to other types of radiation treatment (1 week)
- Preservation of organ structure and function
- Fewer side effects
- Excellent coverage of possible microscopic extension of cancer
- Knowledge of radiation dose distribution before treatment is given
- Accuracy and precision of tumor specific radiation dose delivery
- Minimizes areas of radiation overdose (hot spots) or underdose (cold spots)
- Organ motion (target movement) is not a problem for HDR as it is with external beam
Prostate Specific
- Effective treatment for cancer recurrence (termed “salvage” therapy)
- No radiation source (seeds) migration into other organs
- No radiation exposure to other persons
Breast Specific
- Conserves the breast and yields excellent cosmetic results
- Reduces radiation dose to the heart, lungs, and opposite breast
- Doesn’t cause a delay in other treatments such as chemotherapy
“Our findings mean that some of the tradeoffs between brachytherapy and whole-breast irradiation may be more complex than initially appreciated,” Smith said.
The study, published today in the Journal of the American Medical Association, is the first to compare the effectiveness of brachytherapy with whole-breast irradiation.
In brachytherapy, also called accelerated partial breast irradiation, doctors use a catheter to deliver radiation to a specific area rather than delivering the radiation to the entire breast. It’s a more targeted way to treat the cancer and takes far less time – women can complete brachytherapy in about one week compared with the average of six weeks needed for whole-breast radiation.
Brachytherapy Side Effects
Some women have experienced minor bruising, redness and discomfort. All of these side effects are common in breast surgery and radiation treatment and usually last 2-4 weeks.
Scarring from the tube and button insertion sites or mammosite insertion site decrease and fade over time.
With time and convenience on its side, brachytherapy has become increasingly popular in the past decade. In 2007, about 13 percent of breast cancer patients received it as their only treatment, up from about 4 percent in 2003.
However, so far, no large clinical trials have compared brachytherapy with whole-breast irradiation to test which is more effective.
Many doctors have worried that targeting only a small portion of breast tissue with radiation might miss cancer cells lurking elsewhere in the breast that could develop into cancer later on.
“Whole breast irradiation effectively treats those areas as well,” said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society. “The question has always been whether the use of these newer techniques has that same benefit of treating those silent areas that we know exist in other parts of the breast.”