What Happens During a Sentinel Node Biopsy

If breast cancer spreads, it usually spreads first to the lymph nodes under your arms. The sentinel lymph node is the node it reaches first.

During a sentinel lymph node biopsy, a specially trained surgeon injects a radioactive dye in the area of the tumor. This dye travels to the sentinel node. The dye lets your surgeon see the sentinel node so that he or she can remove it. Then, the surgeon sends it to a lab for examination.

If there is no cancer in the sentinel node, then the rest of your underarm nodes don’t need to be taken out.

If there is cancer in the sentinel node, your surgeon may remove more of your underarm lymph nodes. This may be done at the same time or several days later, depending upon how easily the cancer can be seen in the sentinel node at the time of surgery.

Sentinel node biopsy is often followed by breast-conserving surgery or a mastectomy.

This biopsy may be scheduled for the same time as breast-conserving surgery, or it can be done separately.