Sentinel Node Biopsy
What is a Sentinel Lymph Node Biopsy?
This is an operation to remove the first lymph glands that are responsible for draining the particular area of the chest or leg, involved by a tumour.
A sentinel lymph node biopsy (SLNB) is carried out under general anaesthetic. Usually you have it at the same time as the wide local excision operation to remove the melanoma.
What are Lymph Nodes?
Lymph glands play an important role in the body’s mechanism for fighting infections and tumours, and together with other vessels, the lymphatic system drains the lymph fluid through the lymph glands.
How are the Sentinel Lymph Nodes identified?
A mildly radioactive liquid is injected into the area where the melanoma was removed, the day before your surgery. The dye or liquid drains away from the area and becomes trapped in the Sentinel Node, which can be seen on a Nuclear Medicine scan. The scan will only show where the lymph node is.
A blue dye is then injected once you are asleep and this will send the sentinel lymph node blue helping the surgeon to find the correct one to remove.
The surgeon can see when the dye reaches the first group of lymph nodes or they can measure the radioactivity with a probe. The surgeon removes 1 or more of these nodes and sends them to the lab to see if they contain melanoma cells.
Advantages of SLNB
This is an accurate way of staging the disease, with a smaller operation, less side effects and a faster recovery.
If the lab finds that none of the lymph nodes contain melanoma cells, you won't need to have any more nodes removed. If the sentinel lymph nodes contain melanoma cells, there is a risk that other lymph nodes may also contain melanoma cells. You will usually need to have a further operation to remove the other lymph nodes in the area. This operation is called a lymphadenectomy.
We know that sentinel node biopsy is a useful way to find the stage of melanoma. It can tell you whether your melanoma has spread into the lymph nodes, but it is not a treatment for the melanoma itself.