At Humber River Regional Hospital, many axillary dissections are performed annually on breast cancer patients to assess the spread of cancer cells. The hospital has purchased two new gamma cameras to be used for sentinel node biopsies, bringing patient care for breast cancer another step into the 21st century. “Just as lumpectomy did away with the need for mastectomy, sentinel node biopsy will do away with conventional axillary node dissections,” says Humber River Regional Hospital Surgeon, Dr. Laura Whiteacre.
A 97 per cent rate of accuracy and less invasive procedure are just some of the benefits being touted for women undergoing the procedure to assess the spread of cancer cells. It is quick and painless and unlike the conventional procedure will spare women the anxiety and discomfort of postoperative arm swelling, usually associated with it. This and other potentially debilitating complications, such as nerve damage, are markedly reduced with this new procedure.
The new navigator gamma guidance system functions like a metal detector, identifying the immediate location of the cancerous cells. The secret to this procedure lies in locating the “gatekeeper”, or sentinel node, which collects fluid from the tumor in the breast. The cancer cells must get past the sentinel node to have access to the other lymph nodes. If cancer is found in the sentinel node, it is likely to be in others as well.
Sentinel node biopsy is performed on patients a number of hours before they go into the operating room. A small amount of blue dye and a radioactive substance are injected in and around the tumour. The radiation used is not harmful and is less than the amount used in a standard chest x-ray.
The hand held camera functions like a geiger counter, detecting radioactivity, and finds the sentinel node by locating the area with the highest radioactive count. The node will also be stained blue, aiding in its identification. It is removed through a small incision, leaving the remaining lymph nodes intact. Whereas traditional biopsies remove multiple lymph nodes from the arm pit, offering patients only a 50 per cent chance of locating the cancerous cells. “Now that Humber River has departed from using this traditional procedure, many cancer-free patients will stave off unnecessary surgery,” says Dr. Whitecare. Only women with cancer in their sentinel node will need to have the rest of their lymph nodes removed. The procedure also identifies those patients who would otherwise be under treated.
This combined with lumpectomy allows for the least amount of pain and deformity for women and can easily be performed on an outpatient basis.
In 2002, an estimated 20,500 women will be diagnosed with breast cancer and 5,400 will die of the disease, according to the Canadian Cancer Society. This makes it the most frequently diagnosed and the second deadliest cancer for women.