Sentinel Lymph Node Biopsy

A sentinel lymph node biopsy is a procedure used to diagnose and stage certain types of cancer. It is used to determine whether cancer cells have spread beyond the primary tumor to the lymph nodes. The removal and analysis of the sentinel lymph node(s) can help guide treatment decisions and help predict the outcome of the disease.

The sentinel lymph node is the first lymph node(s) in the lymphatic drainage pathway from the tumor. It is the first to receive lymphatic drainage from the primary tumor and is therefore the lymph node most likely to harbor cancerous cells should they have spread beyond the primary tumor. The sentinel lymph node is identified through radioisotopic or blue dye techniques. Once identified, the lymph node(s) is surgically removed for further analysis.

The advantages of sentinel lymph node biopsy include improved accuracy of diagnosis, increased accuracy of staging, and more accurate prognostic information. It is also less invasive than a full lymph node dissection and has a lower risk of side effects such as lymphedema or infection.

The most common indications for sentinel lymph node biopsy include melanoma, breast, and oral and oropharyngeal cancers. It is generally accepted that the use of sentinel lymph node biopsy should be considered in any patient with a tumor that has the potential to spread to the lymph nodes.

Process of Sentinel Lymph Node Biopsy

The patient receives an injection of a radioactive substance (technetium-99m sulfur colloid) or a blue dye (methylene blue) into the area surrounding the primary tumor.
The lymph nodes in the drainage from the primary tumor take up the dye or radioactive substance.
The surgeon can then identify the sentinel lymph node(s) by using a handheld gamma probe or other specialized imaging techniques.
The sentinel lymph node(s) can then be surgically removed and sent for pathology evaluation.

Risks of Sentinel Lymph Node Biopsy

As with all surgical procedures, there are some risks associated with a sentinel lymph node biopsy. These include infection, bleeding, scarring, and nerve injury. Risks specific to a sentinel lymph node biopsy include spreading of the cancer cells, failure to detect lymph node metastases, and an increased risk of lymphedema.

Although the risks are small, it is important to discuss all the potential risks and benefits of the procedure with your physician prior to undergoing a sentinel lymph node biopsy. Your doctor can help you decide if the procedure is right for you.