Sentinel Node Biopsy Test and Procedure
Overview
A sentinel lymph node biopsy (SLNB) helps doctors determine if cancer has moved beyond its original site by checking the nearby lymph nodes. Doctors commonly perform this test for breast cancer, melanoma, and certain other cancers. The sentinel nodes are the first lymph nodes that cancer cells are likely to reach if they leave the main tumor.
Key steps in a sentinel node biopsy include:
- A doctor injects a special tracer to highlight the sentinel nodes
- The surgeon removes these highlighted nodes
- Laboratory staff analyze them for the presence of cancer cells
| Purpose | Method | Result Impact |
|---|---|---|
| Check for spread | Tracer finds sentinel nodes | Guides next treatment |
| Guide treatment | Nodes removed surgically | May prevent extra surgery |
If no cancer is found in the sentinel nodes, further lymph node removal is often not required. If cancer is detected, more nodes may need to be checked.
Reasons for Sentinel Node Biopsy
Doctors use sentinel node biopsy to determine if cancer has moved beyond the original tumor. This procedure plays a key role in creating effective treatment plans for people with cancer.
Doctors especially use it for those with breast cancer, melanoma, endometrial cancer, and penile cancer, and it provides valuable information for managing other types of cancer, including cervical cancer, head and neck cancer, non-small cell lung cancer, stomach cancer, thyroid cancer, esophageal cancer, colon cancer, and vulvar cancer.
The main benefit of this biopsy is that it helps identify cancer at an early stage if it has spread to the lymph nodes. Knowing whether the lymph nodes contain cancer helps doctors decide if treatments like chemotherapy, radiation therapy, or surgery are needed.
Doctors use the results to decide if someone needs more treatment or close monitoring. This can help spare patients from unnecessary treatments. It also helps predict how the disease could behave and allows for more precise and targeted cancer treatment.
Possible Complications
Lymphedema sometimes occurs after a sentinel node biopsy. Lymph fluid can build up in the tissue, causing areas like the arm or hand to become puffy. This problem is not common after a sentinel node biopsy, because the surgeon removes only a small number of lymph nodes during the procedure.
- Symptoms: Swelling, pain, discomfort, or tightness.
- Risk Level: Low after sentinel node biopsy.
- Other Effects: Numbness, bruising, and seroma (fluid collection) can also occur.
- Rare Effects: Allergic reactions to the dye used in the procedure.
The chance of significant swelling is small because the remaining lymph nodes can usually handle the extra fluid.
Getting Ready for the Procedure
Patients usually need to avoid eating or drinking for several hours before surgery. This reduces the risks linked to anesthesia. Common preparations include:
- Checking with the care team for clear instructions.
- Having a recent mammogram if needed.
- Reviewing any medicines that may affect the immune system or lymphatic fluid.
What You Can Expect
Before surgery, the care team prepares patients to identify the sentinel lymph nodes, which are the first lymph nodes to which cancer may spread. Doctors often use two methods: injecting a small amount of radioactive fluid or a special blue dye near the tumor area.
- The radioactive substance is usually injected a few hours before surgery. It spreads through the lymphatic system and collects in the sentinel nodes.
- The blue dye is injected just before the operation and colors the sentinel nodes blue so they are easy to spot.
Patients might see a blue tint at the injection site or even in their urine temporarily. Both approaches may be used in the same procedure, depending on the doctor’s choice. The selected method helps the surgical team find the sentinel lymph nodes with accuracy.
| Method | Timing Before Surgery | Notes |
|---|---|---|
| Radioactive Solution | Several hours before | May feel a mild pinch |
| Blue Dye | Just before surgery | Can cause temporary blue skin or urine |
What Happens During Surgery
For most patients, the anesthesiologist gives medicine to make them sleep deeply and prevent pain during surgery. The surgeon cleans the area and makes a small incision over the lymph node region, commonly in the underarm or near the tumor.
- If a radioactive tracer is used, a gamma detector locates areas with the highest radioactivity.
- With blue dye, the sentinel lymph nodes will be stained blue for easy recognition.
The surgeon carefully removes a few sentinel nodes (often called SLN) through this small incision. Laboratory staff later analyze these nodes under a microscope to check for cancer cells.
In many cases, the surgeon performs the sentinel node biopsy at the same time as the main cancer surgery, such as a mastectomy or axillary lymph node dissection (ALND). Sometimes, the team schedules it separately, depending on the treatment plan.
Key Steps ring urgery
- The surgeon makes a small surgical cut near lymph nodes.
- Special tools or dye help locate sentinel nodes.
- The surgeon removes sentinel nodes and sends them for cancer testing.
After Your Surgery
After the procedure, recovery begins in a hospital or clinic recovery room. Medical staff monitor the patient for immediate problems, such as bleeding or reactions.
- Most people can go home the same day unless additional treatments or surgeries are necessary.
- Mild pain, swelling, or bruising near the incision is common for a few days.
- Tiredness or changes in skin color from the blue dye may happen but are usually temporary.
Recovery Time Table
| Symptom/Effect | Expected Duration |
|---|---|
| Pain or bruising | Few days |
| Blue skin/urine | A short time, temporary |
| Incision healing | About two weeks |
Doctors provide guidance on when to resume regular activities. If a more extensive procedure, like an axillary dissection, is performed, the hospital stay and recovery may be longer. Most scars heal over time, and serious side effects rarely occur when trained professionals perform the sentinel lymph node biopsy.
Results
After the surgeon removes the sentinel lymph nodes, a pathologist checks them for cancer cells.
- Negative Biopsy: If no cancer is found, more lymph nodes usually do not need to be taken out.
- Positive Biopsy: If cancer cells are present, the team may need to remove more lymph nodes to check how far the cancer has spread.
Biopsy results guide further treatment. Sometimes, the team checks the nodes during the same surgery. If cancer is detected, the team may remove more nodes immediately. There is also a chance of a false-negative result, where cancer is present but not found in the tested nodes.
