Ask the Expert: MammoSite

Q. What is MammoSite?
A. MammoSite is a form of radiation therapy that makes treatment of breast cancer less invasive and decreases treatment time.  It is used for early stage breast cancer patients after their tumor has been removed to prevent it from returning.  Treatment is completed within a 5 day period whereas conventional radiation treatment lasts 6-7 weeks.

Q. How does it work?
A. Once the cancerous tumor has been removed a small, flexible tube or catheter is placed in the breast lumpectomy cavity (the space left when a tumor is removed) with a small incision.  A soft balloon that is attached to the catheter is inflated in the lumpectomy cavity with a saline solution.  Through the catheter a radiation seed is inserted into the balloon.  This treatment typically continues for 2 doses per day for 5 days.  During treatment the balloon remains inside the breast and the catheter remains outside, but is cushioned with gauze.  There is no radiation source in the body between each treatment.  There is no exposure to the patient’s family during the treatment.  Once treatment is over the balloon and catheter are removed and the patient can return to normal activities. 

Q. What are the benefits?
A. MammoSite therapy is beneficial for many reasons.  It places radiation treatment at the direct site of the tumor where the recurrence risk is the greatest.  The radiation exposure and effects are therefore limited.  In addition, higher daily doses can be delivered, allowing treatment to be completed in just 5 days.  MammoSite is well tolerated, and only mild side effects are expected.  The most frequent side effects that may occur are mild redness, bruising, and breast pain. The incision is small so the catheter insertion site heals relatively quickly.  Treatment is given on an outpatient basis.

Q. Is MammoSite effective?
A. MammoSite can be a very effective treatment option for early-stage breast cancer patients.  Thousands of women in the United States have been treated with MammoSite.  A clinical trial reported that the majority of treated patients would recommend MammoSite to a friend or family, as well as choose MammoSite if they had to do it over again.  Current research has shown that this treatment for breast cancer results in low rates of breast cancer recurrence.  A current trial is being performed to substantiate these very promising findings compared to conventional radiation therapy.

Q. Where is the treatment available?
A. The American Society of Breast Surgeons and the American Brachytherapy Society recommend this treatment for breast cancers that are 3 cm or smaller, and have no spread of cancer to the lymph nodes.  If you are a candidate for MammoSite therapy it is available at The Cancer Center at Ball Memorial Hospital.

Steve Tilmans MD, is a board certified radiation oncologist and a member of Ball Memorial Hospital’s clinical staff.