Sentinel Lymph Node Mapping is a procedure that detects early metastases (spread) to the lymph nodes of the axilla (armpit). The sentinel lymph node is thought to represent the “first” lymph node to receive drainage from the primary site of the breast cancer.

A small amount of radioactive tracer material is injected into the breast tissue prior to surgery and an X-ray picture is taken to visualize the lymph node system. The surgeon also uses a small probe to find the lymph node in the operating room. If the sentinel lymph node is free of cancer, the other lymph nodes in the axilla may not need to be removed. This minimizes the risks and side effects of a full lymph node dissection.

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