Sentinel lymph node surgery is a procedure that identifies the first, or sentinel, node or nodes that receive lymphatic fluid from a cancerous tumor. Tumors may drain to different node chains in the breast, according to the position of the tumor. This procedure identifies the nodes most likely to show whether or not the cancer has metastasized from the original tumor. This information is needed by the oncologist to determine the need for chemotherapy. This identification allows the surgeon and the pathologist to have a reliable guide for more accurate node evaluation.
The area surrounding the tumor and/or the areola is injected with a dye and/or radiographic substance several hours before surgery. Before the incision is made on the breast, a hand-held gamma-detection probe identifies for the surgeon the greatest area of radiographic uptake. This guides the surgeon to the lymphatic chain that drains the tumor, allowing removal of the node(s) stained by the dye or identified by the hand-held probe. The single node (or nodes) is removed and during surgery is sent to pathology for immediate evaluation. The pathologist can often report to the surgeon during surgery. If cancer cells are present, a standard auxillary lymph node dissection is most often done at this time requiring a drain and increasing recovery time. If the pathologist does not evaluate the nodes during surgery, additional surgery may be required later if the nodes are positive.
Not all patients are candidates for this procedure. Pregnant women, women with known positive nodes, certain size tumors, women with DCIS (ductal carcinoma in situ, a non-invasive breast cancer) or women with more than one tumor in the breast may be ineligible. Your surgeon will inform you if you are a candidate and discuss the procedure with you.