Nuclear Medicine: Mapping Scans

Mapping refers to the tracking of a tracer (a radioactive chemical injected into the body) to see where it collects in a particular organ or area of interest. Breast cancer and skin cancer spreads away from primary tumor site through the lymphatic system (lymph nodes). Mapping is done primarily of the sentinel lymph node, the hypothetical first lymph node or group of nodes reached by cancer cells moving away from a primary tumor. Parathyroid tumor marking is another mapping procedure.

Sentinel lymph node mapping is important for prognosis and treatment of breast and skin cancer.  The sentinel lymph node(s) are closely analyzed under a microscope for any presence of tumor cells.  This technique decreases the need to remove all of the lymph nodes draining a particular extremity.