Before the procedure
The first step in a sentinel node biopsy is to locate the sentinel nodes. Options include:
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 might inject a harmless blue dye into the area near the tumor. Your lymphatic system delivers the dye to the sentinel nodes, staining them bright blue.
You might notice a change in your skin color at the injection site. This color usually disappears in time, but it can be permanent. You might also notice that your urine is blue for a brief time.
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 or both to locate the sentinel nodes is usually determined by your surgeon's preference. Some surgeons use both techniques in the same procedure.
During the procedure
You're likely to be under general anesthesia during the procedure.
The surgeon begins by making a small incision in the area over the lymph nodes.
If you've received radioactive solution before the procedure, the surgeon uses a small 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 one to five 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. Or, sentinel node biopsy can be done before or after surgery to remove the cancer.
After the procedure
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 have 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.
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.