Sentinel Lymph Node Biopsy
Katherine McCuaig, MD, is a physician that practices at Banner Baywood Medical Center in Mesa.
Question: My friend was just diagnosed with breast cancer and says she needs a sentinel lymph node biopsy with her breast surgery. What is that?
Answer: Whether or not breast cancer has spread to nearby lymph nodes is one of the most important factors determining patient survival and the likelihood of a patient requiring chemotherapy. In the past, all the lymph nodes in the armpit (axilla) were removed, leading to an increased risk of arm swelling (lymphedema) and susceptibility to infection.
Only a minority of 30 percent of patients have breast cancer involving their nodes, so a less invasive procedure -- sentinel lymph node dissection -- is used to identify those individuals. Researchers noted that most lymph vessels in the breast first drain to only a few nodes in the armpit before draining into the remaining nodes. If cancer has spread to the lymph nodes, it usually spreads to these "sentinel nodes" first.
During the procedure, radioactive tracer and/or blue dye is injected into the skin around the nipple. In the operating room, a surgeon uses a pencil-like device with a gamma counter to identify the "hot" sentinel nodes. These nodes are removed and sent to pathology. If they are cancer-free, the remaining nodes are left in the axilla. If cancer is detected, the remaining nodes are removed.
This technique helps us spare those individuals who do not need it from a complete axillary node dissection, reducing their risk of future lymphedema.