In late 2011, Memorial Sloan-Kettering began offering women a new procedure to more precisely pinpoint and remove small breast cancers that can be detected on a mammogram but not felt in the breast. The method, called radioactive seed localization (RSL), begins with a breast radiologist injecting one or two tiny, sealed radioactive sources called seeds into the patient’s breast to mark the exact location of the cancer.
In the operating room, surgeons use a handheld radiation-detection device developed specifically for this procedure to zero in on the seed and precisely locate the cancer, which is removed along with the seed during the operation. No radioactivity is left in the body after the surgery.
Now, a multidisciplinary team of medical physicists, radiologists, pathologists, and surgeons, led by medical health physicist and radiation safety manager Lawrence T. Dauer, has detailed their initial year’s experience using RSL. Their report, published in the October issue of the journal Health Physics, shows that the procedure is safe and effective, and offers benefits to both patients and medical staff.
Memorial Sloan-Kettering was the first hospital in the tri-state area to offer RSL, which is now standard practice for the majority of our patients with small breast cancers, and our experts have the most experience in the region with this technique.
Drawbacks of the Traditional Method
Traditionally, patients with small breast cancers have had the position of their tumor marked for surgery with breast needle localization (also called wire localization), in which a radiologist inserts a needle with a fine wire into the breast a few hours before a biopsy or lumpectomy. Because the wire remains partially outside the breast, it can be inadvertently moved before or during the surgery, which may limit the surgeon’s ability to locate the cancer and remove it completely.
In addition, the wire can be uncomfortable for patients, and because it must be placed in the breast the same day as surgery, wire localization is not only difficult to schedule in a busy hospital, it requires the patient to spend several extra hours at the hospital on the day of surgery.
Advantages of the New Procedure
Over the course of one year, radioactive seed localization was performed on more than 1,000 women who had small breast tumors surgically removed at Memorial Sloan-Kettering. The research team found that the new procedure has significant benefits over breast needle localization, including fewer scheduling conflicts and a better overall patient experience. While surgeons have had years of experience using breast needle localization, in only one year the new technique produced similar operating times and the same likelihood that the cancer is removed completely.
“Our findings validate our initial enthusiasm for the procedure and show that it is safe, with significant advantages for both our hospital staff and our patients,” says Dr. Dauer. “The total length of time a patient needs to be in the hospital is drastically reduced, and our efficiency in the operating room is improved.”
Monica Morrow, Chief of the Breast Surgical Service and a coauthor of the report, adds, “For women with small breast cancers that can’t be seen or felt, a surgeon needs a reliable map to completely remove all cancerous tissue. Radioactive seed localization is the most patient-friendly mapping system we have available.”
The use of RSL at Memorial Sloan-Kettering was initiated by Elizabeth A. Morris, Chief of the Breast Imaging Service, and Jean St. Germain, an attending physicist and radiation safety officer, who were also involved in the research.