Sentinel Node Biopsy

What is a sentinel lymph node biopsy?

• This procedure is where the sentinel lymph node is located, removed and tested to detect if cancer cells are present.
• Lymph nodes are part of the body’s immune system which fight infection and filter cancer cells from the body.
• The theory is that cancer can spread from one part of the body to another through lymph nodes and the sentinel is the hypothetical first lymph node draining a cancer.
• Breast cancer cells are most likely to spread to lymph nodes in the armpit or axilla next to the affected breast.
• A positive SLNB indicates the presence of cancer which may have spread to other nodes and possibly, other organs.
• It is important information for a doctor to help determine work out the extent of the disease in the body and to formulate an appropriate treatment plan.
• A SLNB is usually done in the same surgery to remove the primary tumour.

What happens during a sentinel lymph node biopsy?

• Patients require two procedures to isolate the sentinel lymph nodes.
• The first is a nuclear medicine scan usually performed on the day of the operation.
• While under general anaesthetic, a radioactive substance and/or a blue dye is injected into the patient, near the tumour, to identify the position of the sentinel lymph node.
• A device known as a gamma probe is then used to detect radioactivity or search for lymph nodes that are stained with blue dye.
• Once located the surgeon makes a small incision and removes the node.
• A pathologist checks for the presence of cancer and, if found, the surgeon may remove additional lymph nodes either during the same biopsy procedure or in a follow up operation.
• The benefit of SLNB is that only a few lymph nodes are removed thereby avoiding or reducing complications that can arise with a more extensive lymph nodes surgery (complete axillary lymph node dissection).