lymphoscintigraphy

(LIM-foh-sin-TIH-gruh-fee) A method used to identify the sentinel lymph node (the first draining lymph node near a tumor). A radioactive substance that can be taken up by lymph nodes is injected at the site of the tumor, and a doctor follows the movement of this substance on a computer screen. Once the lymph nodes that have taken up the substance are identified, they can be removed and examined to see if they contain tumor cells.