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Sentinel Node Biopsy

Excision of draining lymph nodes to test for the microscopic spread of cancer. This is usually combined with an operation for breast cancer or melanoma but on occasion is done as a separate procedure.

What is a sentinel node biopsy?

A sentinel node biopsy is part of treatment and staging for a number of cancers.  It is commonly used in breast cancer and melanoma. Sentinel nodes are the lymph nodes that are the first draining nodes of an area.  There are a variable amount of sentinel nodes, usually 1 – 3. Any that are identified as sentinel nodes are removed during the operation.

Why should I have a sentinel node biopsy?

A sentinel node biopsy is part of your cancer staging and treatment. The aim is to identify any microscopic spread of cancer to the lymph nodes, which cannot be detected on clinical examination or imaging. If there is cancer within the lymph nodes your ongoing management is different so it is important to know.

How is the surgery performed?

The day prior to the operation you will have a special tracer/radioisotope injected into the site of cancer which then travels in the lymphatic vessels and is taken up by the sentinel nodes.  These nodes are then able to be located with a gamma probe in theatre. If you are having a sentinel lymph node biopsy for melanoma you will also have blue dye injected into the area once you are asleep.  Some people with breast cancer will need blue dye too. You will have a general anaesthetic. The incision will depend on the primary site of cancer and this will be discussed with you before your operation. Any lymph nodes identified as sentinel nodes by blue dye or radioisotope are removed.  If there are any nodes which feel abnormal these are removed also.  The amount of nodes removed is different in each patient. Your wound will be closed with dissolvable sutures and a waterproof dressing will be placed.

What are the risks of sentinel node biopsy?

Bleeding. Infection.  Seroma formation.  Need for further operation if the lymph nodes are found to contain cancer.  Injury to the intercostal-brachial nerve resulting in numbness/tingling along the inner arm. Injury to the long thoracic or thoracodorsal nerve. Allergy to blue dye 1:600. Lymphoedema 3 – 6%.

Before the operation

The day prior to the operation you will go to Waikato for an injection of radioisotope. You will be admitted on the day of your operation. You cannot eat or drink for 6 hours prior to your procedure.

After the operation

The length of stay will depend on what other surgery you have in conjunction with the sentinel node biopsy. If you go home the same day you will need someone to drive you home. You should take regular simple pain relief. Leave your dressing on for 1 week, then it can be changed. You will be seen in the rooms for follow up and review of results after 3 weeks.