Dr. Karthik Chandra VallaM
(MBBS, M.S, M.Ch, D.N.B Surgical Oncology)
SLNB (sentinel lymph node biopsy) is a surgery that is mainly done to determine the stage of specific cancers, like breast cancer and melanoma. The main goal of this procedure is to locate and take a sample from the sentinel lymph node(s), which are the first lymph nodes that cancer cells are expected to spread to from the original tumor site. Let me give you a brief explanation of how this procedure is carried out:
What are lymph nodes?
Lymph nodes are small, circular structures integral to the body's lymphatic system, which plays a vital role in immunity. This system comprises a complex network of vessels and organs containing lymph, a clear fluid transporting white blood cells for combating infections, as well as fluids and waste materials from the body's cells and tissues. Additionally, in individuals with cancer, lymph can serve as a conduit for cancer cells that have detached from the primary tumor.
What is a sentinel lymph node?
A sentinel lymph node is the first lymph node where cancer cells are most likely to spread from a primary tumor. Sometimes, there may be more than one sentinel lymph node.
When is a sentinel node biopsy performed?
Doctors mostly use sentinel node biopsy to stage breast cancer and melanoma. Staging helps them determine if cancer is spreading and how serious it is.
Sentinel node biopsy is routinely used for people with:
- Breast cancer
- Endometrial cancer
- Penile cancer
Researchers and healthcare providers are exploring the potential use of sentinel node biopsy for staging other types of cancer, such as:
- Cervical cancer
- Colon cancer
- Esophageal cancer
- Head and neck cancer
- Non-small-cell lung cancer
- Stomach cancer
- Thyroid cancer
- Vulvar cancer
What is a sentinel lymph node biopsy?
Sentinel lymph node biopsy (SLNB) is a procedure used to locate, remove, and examine the sentinel lymph node to determine if cancer cells are present. It is typically performed on individuals who have been diagnosed with cancer.
A negative SLNB outcome indicates that the cancer hasn't spread to nearby lymph nodes or other organs yet.
If the SLNB result is positive, it means that cancer has been found in the sentinel lymph node. This suggests that it also spreads to nearby lymph nodes and potentially other organs. This valuable information allows doctors to determine the stage of the cancer and create a suitable treatment strategy.
What happens during an SLNB?
The surgeon starts by finding the sentinel lymph node either by injecting a radioactive substance, a blue dye, or both near the tumor. They then use a special device to locate the lymph nodes that contain the radioactive substance or look for lymph nodes stained with the blue dye. Once located, the surgeon makes a small cut in the skin and removes the sentinel lymph node.
A pathologist examines the sentinel node to check for any cancer cells. If cancer is found, the surgeon may remove more lymph nodes during the same biopsy or in a later surgery. The sentinel lymph node biopsy can be done as an outpatient procedure or may require a short hospital stay.
Usually, the SLNB is done at the same time as removing the main tumor. However, in some cases, it can also be done before or after the tumor removal, depending on how much the lymphatic vessels have been affected.
What are the benefits of SLNB?
Sentinel lymph node biopsy (SLNB) helps doctors determine the cancer stage and assess the risk of tumor cells spreading to other body parts. If the sentinel node shows no signs of cancer, avoiding more invasive lymph node surgery may be possible. This can reduce the risks and complications associated with removing multiple lymph nodes.
Sentinel node biopsy is usually a safe procedure, but like any surgery, there is a chance of complications, such as:
- Pain or bruising at the biopsy site.
- Allergic reaction to the dye used for the procedure.
- Fluid buildup and swelling in lymph vessels, which is called lymphedema.
Limitations of Sentinel Node Biopsy:
- Keep in mind that false negative results can occur, which means that even if the sentinel node biopsy comes back negative, there is still a chance that cancer cells might be present in other lymph nodes.
- It's important to note that this procedure may not be suitable for every type and stage of cancer.
- There are potential risks of complications related to the surgery itself, anesthesia, and the injection of tracer or dye.
In summary, sentinel node biopsy is an important tool in managing specific cancers, offering essential information for staging and treatment planning while reducing the need for extensive surgery and associated risks.