Sentinel lymph node biopsy for the detection of metastases

Although the concept of the sentinel node has existed for most of the twentieth century, it was only in the last decade that methods were developed which allowed practical application to cancer patients. Sentinel nodes (SN) are a highly variable but limited set of lymph nodes first to receive drainage from any given location. Cancer metastasizes to these nodes before other nodes. Radioactive tracers and blue dyes are used to guide the surgeon to the SNs for resection. Two large clinical trials of SN surgery in breast cancer patients are actively underway in the United States. Until the impact of this very promising technology is confirmed to provide the same staging and prognosis, regional control, and survival as conventional surgery, it is considered an experimental procedure.