After lumpectomy to remove early-stage breast cancer, radiation therapy commonly is given to reduce the risk of the cancer coming back (recurrence). Lumpectomy and radiation are a good alternative to mastectomy.
A study found that three alternatives to traditional external beam radiation therapy are all equally effective at lowering the risk of recurrence and offer the same benefits as traditional radiation therapy. The results were presented at the 2009 ASCO Breast Cancer Symposium.
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 radiation source for external beam therapy is outside the breast, which is what makes it "external." Drawbacks of traditional radiation therapy include daily trips to the hospital for treatments (typically 5 days a week for 4 to 6 weeks) and unintended exposure of nearby healthy tissue (lungs or heart, example) to radiation.
To overcome the drawbacks of traditional radiation therapy, doctors have developed different ways to deliver radiation. These new techniques are called "accelerated partial breast irradiation." The new techniques deliver more focused and intense radiation therapy over a shorter period of time. Because the radiation is more focused, the new techniques may cause fewer or milder side effects than traditional radiation therapy.
The three accelerated partial breast irradiation techniques evaluated in this study are:
- multi-catheter internal radiation (interstitial needle-catheter brachytherapy)
- balloon internal radiation (MammoSite)
- 3-D conformal external beam radiation (3DCRT)
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 (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. (199 women received this type of radiation.)
Balloon internal radiation places a special catheter with a balloon on the end in the place 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. (80 women received this type of radiation.)
3-D conformal external beam radiation uses 3-dimensional CAT scan or MRI imaging before radiation therapy to plan more precise delivery in three dimensions of more intense radiation. Because each treatment delivers more intense radiation in a more focused way (compared to traditional radiation therapy), treatment may be completed in 1 week. (94 women received this type of radiation.)
Five years after diagnosis, the researchers compared the treatment outcomes of the three types of accelerated partial breast irradiation and found no real differences:
- survival rates (with no recurrence) ranged from 92% (3-D conformal radiation) to 96% (brachytherapy and MammoSite)
- local recurrence (cancer coming back in the same breast) ranged from 1.1% (3-D conformal radiation) to 1.6% (MammoSite)
- distant recurrence (cancer coming back in the body away from the breast) ranged from 1.3% (MammoSite) to 6.6% (3-D conformal radiation)
These differences were small enough to have happened by chance, not because of the different irradiation techniques.
Cosmetic outcomes also were good. The three types of accelerated partial breast irradiation had similar percentages of women who were judged to have good to excellent results, ranging from 89% (3-D conformal radiation) to 99% (brachytherapy).
While these results are promising, more research is needed. More follow-up (longer than 5 years for each technique) is needed before doctors can conclude with confidence that these techniques are comparable to each other and to traditional external beam radiation therapy. While there are more than 10 years of follow-up study on women who received brachytherapy, the follow-up periods for the other two groups are closer to 5 years.
If you've been diagnosed with early-stage breast cancer and lumpectomy followed by radiation therapy will be part of your treatment, ask your doctor about the radiation therapy options that make the most sense for you. Things you'll likely consider include:
- the specifics of the cancer (size, location, lymph node involvement)
- your personal preferences (how important is having a shorter total radiation therapy treatment time)
- the experience level and results of the doctors who will administer your radiation therapy
Together you and your doctor will make the best choice for you and your unique situation.
Visit the Breastcancer.org Radiation Therapy section to learn more about all radiation therapy techniques.