Sentinel lymph node biopsy
A sentinel lymph node biopsy (SLNB) is a procedure that helps to identify if cancer is in your lymphatic system (the system in your body that produces and stores cells that fight infection and disease).
Lymph nodes (or glands) are part of your body's immune system, called the lymphatic system. Lymph nodes are found throughout your body, particularly in your armpits, neck and groin. Their main function is to help fight infection and filter lymphatic fluid. The sentinel lymph node is the first local lymph node that cancer cells are most likely to spread to from a cancer.
The process of finding out if cancer has spread is called staging.
In an SLNB, your surgeon will find your sentinel node and remove it. It will then be examined in a laboratory for cancer cells (sometimes your surgeon will remove more than one node).
If cancer cells are found in your sentinel node, you may need to have further surgery. This aims to remove all the lymph nodes in that area of your body (lymphadenectomy). You may need other treatment, such as radiotherapy or chemotherapy. If no cancer cells are found, it means the cancer probably hasn't spread so you shouldn’t need to have any of your other lymph nodes removed.
What are the alternatives?
To stage the cancer (find out if it's spread) and plan appropriate treatment, it can sometimes be useful if your surgeon checks your lymph nodes closest to your tumour for cancer cells.
Depending on the size and location of the cancer you have, your surgeon may suggest you have some or all of your nearby lymph nodes removed. This is done at the same time as you have the primary tumour removed. For example, in some types of breast cancer, your surgeon will remove the lymph nodes in your armpit at the same time as your breast tumour.
Preparing for sentinel lymph node biopsy
Your surgeon will explain how to prepare for your procedure. For example, if you smoke, you will be asked to stop as smoking increases your risk of getting a chest and wound infection. This can slow your recovery.
SLNB is usually done as a day-case procedure. This means you have the procedure and go home the same day. If you're having a tumour removed at the same time, you may need to stay in hospital for longer. The exact amount of time will depend on the type of cancer and operation you have – ask your surgeon for information.
SLNB may be done under general or local anaesthesia. General anaesthesia means you will be asleep during the procedure. Local anaesthesia completely blocks the pain from the biopsy area and you will stay awake during the procedure. You may be offered a sedative with a local anaesthetic. This relieves anxiety and helps you to relax. Your surgeon and anaesthetist will discuss which type of anaesthesia is most suitable for you.
If you're having a general anaesthetic, you will be asked to follow fasting instructions. This means not eating or drinking, typically for about six hours beforehand. However, it's important to follow your anaesthetist's advice.
Your surgeon will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen. You can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead. You may be asked to do this by signing a consent form.