Sentinel Node Injection /
This is a procedure used to help identify the sentinel lymph node(s), which is the first lymph node to which cancer cells are likely to spread from the primary tumor. The procedure involves injecting a radioactive isotope (technetium sulfur colloid) into the breast, generally around the central aspect of the breast. The material moves through the lymphatic channels and accumulates in one or several lymph nodes. During surgery, a handheld gamma ray counter scans the area of the underarm to locate the sentinel node(s).