What does sentinel node dissection involve?
In the operating room, the surgeon injects a radioactive liquid, a blue dye, or both into the area around the tumor. The doctor then watches to see where the dye travels and seems to concentrate. A special instrument is used to track the radioactive liquid. You may think you’re getting another scan during sentinel node dissection, but the doctor is just checking to see where the dye is building up.
This process shows the pathway by which the lymph travels when it drains away from the part of the breast that "housed" the tumor. It indicates which lymph node is the "sentinel node" for a particular tumor. After the sentinel node and one or two nodes closest to it are removed, your surgeon will look at them and feel them in the operating room, to see if they seem to be affected by cancer. This is just a rough exam and doesn't provide definitive information. Next, the nodes are sent to the pathology lab for analysis under a microscope.