Locating the sentinel nodes
The first step in a sentinel node biopsy is to locate the sentinel node. There are two options for locating the sentinel node:
- Radioactive solution. In this option, a weak radioactive solution is injected near the tumor. This solution is taken up by your lymphatic system and travels to the sentinel nodes. This injection is usually done several hours or the day before the surgical procedure to remove the sentinel nodes.
- Blue dye. Your doctor may inject a harmless blue dye into the area near the tumor. The dye is taken up by your lymphatic system and delivered to the sentinel nodes, staining them bright blue. The blue dye is typically injected just before the surgical procedure to remove the sentinel nodes.
Whether you receive the radioactive solution or the blue dye to locate the sentinel nodes is usually determined by your surgeon's preference. Some surgeons use both techniques in the same procedure.
During sentinel node biopsy
Usually, surgeons perform sentinel node biopsy during general anesthesia, so you're not aware during the procedure.
The surgeon begins by making a small incision in the area over the lymph nodes. If you've received the injection of radioactive solution prior to the procedure, the surgeon uses a small hand-held instrument called a gamma detector to determine where the radioactivity has accumulated and identify the sentinel nodes. If the blue dye is used, it stains the sentinel nodes bright blue, allowing the surgeon to see them. The surgeon then removes the sentinel nodes. In most cases, there are two or three sentinel nodes, and all are removed.
The sentinel nodes are sent to a pathologist to examine under a microscope for signs of cancer.
In some cases, sentinel node biopsy is done at the same time as surgery to remove the cancer. In other cases, sentinel node biopsy can be done before or after surgery to remove the cancer.
After sentinel node biopsy
After sentinel node biopsy, you're moved to a recovery room where the health care team monitors you for complications from the procedure and anesthesia. If you don't undergo additional surgery, you'll be able to go home the same day. How soon you can return to your regular activities will depend on your situation. Talk to your doctor about your specific case.
If you have sentinel node biopsy as part of a procedure to remove the cancer, your hospital stay will be determined by the extent of your operation.
Nov. 15, 2011
- Harlow SP, et al. Sentinel lymph node biopsy in breast cancer: Techniques. http://www.uptodate.com/home/index.html. Accessed Oct. 3, 2011.
- Robison K, et al. Update on sentinel lymph node evaluation in gynecologic malignancies. Current Opinion in Obstetrics and Gynecology. 2011;23:8.
- Sentinel lymph node biopsy. National Cancer Institute. http://www.cancer.gov/cancertopics/factsheet/detection/sentinel-node-biopsy. Accessed Oct. 3, 2011.