Sentinel Lymph Node Biopsy

What is a Sentinel Lymph Node Biopsy?

Most people hear about Sentinel Lymph Node Biopsy (SLNB) during discussions of treatment options for breast cancer and less often for melanoma of the skin.  This advanced technique detects lymph node spread of cancer with increased diagnostic accuracy and with fewer complications than traditionally seen.

Currently, when diagnosed with breast cancer, patients have the option of either Breast Conserving Treatment (lumpectomy, lymph node removal from the armpit, and radiation treatments to the remaining breast) or Modified Radical Mastectomy (removal of the breast and the adjacent armpit lymph nodes).  These two surgical options are the “standard of care” treatments for breast cancer.   Potential side effects of armpit lymph node removal can include arm swelling (20-25%), cellulitis of the extremity (approximately 10%), and pain.  When SLNB is added to either surgical option, arm swelling and cellulitis rarely occur and patients have much less pain.  This advanced procedure has been offered by general surgeons at Northeast Medical Center since 2000.  SLNB should ultimately become part of the standard of care for breast cancer in the future.

Anatomy

The typical number of lymph nodes in the armpit can vary from 8 to 30 and are connected together as a group.  Lymph nodes filter body fluids like an oil filter cleans oil in a car.  We are born with hundreds of lymph nodes in many locations of our body.  For breast cancer, the armpit (axillary) lymph nodes are most often the first site of cancer spread. 

Treatment Factors

The presence of cancer within these armpit lymph nodes is the basis for planning treatment and in predicting a patient’s expected lifespan (prognosis).  Following many years of national research, the ability to predict which lymph node (the sentinel lymph node) within a group of lymph nodes is the most likely to harbor cancer spread is highly predictable.  The ability to accurately identify whether cancer has spread to a lymph node group is approximately 97% with SLNB.  In contrast, approximately 3% of cases where SLNB is utilized, the cancer spread to the lymph nodes is missed.

The SLNB Procedure

A very small dose of a nuclear medicine agent is injected into the skin overlying the breast cancer.  Pictures are taken to identify which lymph node within the group has taken up the injected agent.  The patient proceeds to the operating room.  Under anesthesia, a blue dye is injected around the breast cancer by the surgeon.  Both of these injected solutions will drain toward the armpit.  The surgeon uses a handheld Geiger counter (radiation detector) to search for a “hot” lymph node that likely will be blue.  This is the Sentinel Lymph Node (SLN).  This SLN is submitted to the pathologist.  If the SLN does not contain cancer by preliminary testing, the remaining lymph nodes are left in the armpit.  These patients then avoid the potential complications of complete lymph node removal.  However, if the SLN is positive (contains cancer), the remaining lymph nodes in the armpit are removed.  The surgeon then proceeds with the definitive breast operation.

Benefits

Increased diagnostic accuracy of the armpit lymph nodes.
No upper extremity swelling or cellulitis.
Less upper extremity pain.

Expected Side Effects

“Blue or green” urine lasting less than a day.

If you need further information or have questions, please contact us.