What is Sentinel Node Biopsy? Purpose, Levels/Procedure & Results

A sentinel node biopsy is a surgical procedure that removes and tests the first lymph node where cancer cells are most likely to spread from a tumor. Think of it as checking the "gatekeeper" lymph node that filters fluid from the area around your cancer.

This minimally invasive procedure helps doctors determine if cancer has begun to spread beyond the original tumor site. Your medical team uses this information to plan the most effective treatment approach for your specific situation.

What is sentinel node biopsy?

The sentinel node is the first lymph node that receives drainage from a tumor site. During this procedure, your surgeon identifies and removes this specific node to examine it for cancer cells under a microscope.

Your lymphatic system works like a network of highways carrying fluid throughout your body. When cancer cells break away from a tumor, they typically travel through these pathways to the nearest lymph node first. By testing this "sentinel" node, doctors can often determine if cancer has started spreading without removing many lymph nodes.

This targeted approach means less surgery for you while still providing crucial information about your cancer's behavior. The procedure is commonly used for breast cancer, melanoma, and some other types of cancer.

Why is sentinel node biopsy done?

Doctors recommend sentinel node biopsy to determine if cancer has spread to your lymph nodes. This information directly impacts your treatment plan and helps predict your outlook.

The procedure serves several important purposes in your cancer care. First, it helps stage your cancer, which means determining how advanced it is. Second, it guides treatment decisions about whether you need additional surgery, chemotherapy, or radiation therapy.

Before sentinel node biopsy became available, doctors often removed many lymph nodes to check for cancer spread. This approach, called lymph node dissection, can cause permanent side effects like arm swelling. Sentinel node biopsy allows doctors to gather the same important information while potentially avoiding these complications.

What is the procedure for sentinel node biopsy?

The sentinel node biopsy procedure involves injecting a special tracer substance near your tumor, then following its path to identify the sentinel node. Your surgeon removes this node through a small incision for laboratory testing.

Here's what happens during your procedure, step by step:

1. You'll receive anesthesia to keep you comfortable during the surgery
2. Your surgeon injects a radioactive tracer and/or blue dye near your tumor site
3. The tracer travels through your lymphatic system to the sentinel node
4. Your surgeon uses a special probe to locate the radioactive signal
5. A small incision is made to access and remove the sentinel node
6. The node is sent to the pathology lab for immediate or detailed analysis

The entire procedure typically takes 30 to 60 minutes, depending on the location and complexity of your case. Most people can go home the same day, though some may need a brief hospital stay.

How to prepare for your sentinel node biopsy?

Your preparation begins with a pre-surgery consultation where your medical team explains the procedure and answers your questions. You'll receive specific instructions about eating, drinking, and medications before surgery.

Your healthcare team will provide you with detailed preparation guidelines that may include:

• Stopping certain medications that can increase bleeding risk
• Fasting for 8-12 hours before surgery if you're having general anesthesia
• Arranging transportation home after the procedure
• Wearing comfortable, loose-fitting clothes on surgery day
• Removing jewelry, contact lenses, and nail polish

Let your medical team know about all medications you take, including vitamins and supplements. They'll also want to know about any allergies you have, especially to iodine or contrast dyes.

How to read your sentinel node biopsy results?

Your pathology report will clearly state whether cancer cells were found in your sentinel node. A negative result means no cancer cells were detected, while a positive result indicates cancer has spread to the lymph node.

Understanding your results helps you participate in treatment decisions. If your sentinel node is negative, there's typically no need to remove additional lymph nodes. This means your cancer hasn't started spreading through your lymphatic system, which is encouraging news.

If your sentinel node is positive, your doctor will discuss next steps with you. This might include removing additional lymph nodes, adjusting your treatment plan, or adding therapies to target cancer cells that may have spread. Remember that even positive results don't change your ability to receive effective treatment.

What are the risk factors for needing sentinel node biopsy?

Your doctor recommends sentinel node biopsy based on your specific cancer type, size, and location. Certain characteristics of your tumor make lymph node spread more likely, warranting this procedure.

Several factors influence whether you'll need this procedure:

• Tumor size larger than 1-2 centimeters
• High-grade or aggressive cancer cells
• Certain cancer types like breast cancer or melanoma
• Tumor location in areas with rich lymphatic drainage
• Signs of possible lymph node involvement on imaging scans

Your medical team considers these factors alongside your overall health and treatment goals. They'll explain why they're recommending the procedure and how it fits into your comprehensive care plan.

What are the possible complications of sentinel node biopsy?

Sentinel node biopsy is generally safe, but like any surgical procedure, it carries some risks. Most complications are minor and temporary, resolving within a few weeks of surgery.

Common complications you might experience include:

• Temporary bruising or swelling at the incision site
• Mild pain or discomfort that improves with rest and medication
• Temporary blue or green discoloration of skin and urine from the dye
• Numbness or tingling in the area that usually resolves over time
• Small risk of infection at the incision site

Rare but more serious complications can include allergic reactions to the tracer substances, persistent numbness, or lymphedema (fluid buildup causing swelling). Your surgical team monitors you carefully and provides instructions for recognizing signs that need medical attention.

When should I see a doctor after sentinel node biopsy?

Contact your healthcare team immediately if you develop signs of infection, severe pain, or unusual swelling after your procedure. Most people recover smoothly, but knowing warning signs helps ensure prompt treatment if needed.

Call your doctor right away if you experience:

• Fever higher than 101°F (38.3°C)
• Increasing redness, warmth, or pus at the incision site
• Severe pain that doesn't improve with prescribed medications
• Sudden onset of significant swelling in your arm or leg
• Persistent nausea or vomiting

You should also reach out with any concerns or questions about your recovery. Your medical team wants to support you through this process and address any worries you might have.