Understanding Sentinel Lymph Node Biopsy

When treating breast cancer, one of the most important factors to determine is whether the cancer has spread beyond the primary tumor. The lymphatic system is one of the first places it can go. A sentinel lymph node biopsy is a highly advanced and minimally invasive procedure that helps us accurately answer this question.

What is a Sentinel Lymph Node?

The sentinel lymph node (or nodes) is the first lymph node to which cancer cells are most likely to spread from a primary tumor. Think of it as the "guard" or "sentry" of a lymph node basin in the underarm (axilla). By identifying and testing this node, we can get a very accurate picture of whether the cancer has begun to travel.

How Does the Procedure Work?

Before or during surgery, a special blue dye and a safe, low-level radioactive tracer are injected near the tumor. These substances travel through the same lymphatic channels that cancer cells would take. The first lymph node to absorb the dye and tracer is the sentinel node. Dr. Loots then makes a small incision in the underarm to locate and remove this specific node (or sometimes 2-3 nodes).

What are the Benefits?

The removed sentinel node is immediately examined by a pathologist. If it is free of cancer cells, it is highly likely the other lymph nodes are also clear, meaning a full axillary node clearance (removing many more lymph nodes) can be avoided. This is a major benefit for patients, as it leads to:

• A lower risk of side effects like lymphedema (arm swelling).
• Less post-operative pain and numbness.
• Faster recovery and better arm mobility.

This procedure is a crucial part of modern breast cancer surgery, allowing for precise staging with significantly fewer side effects than older methods.