In general, the combination of dye and radioactive label provides for the greatest identification of the sentinel lymph node. Prior to surgery, the injection of dye and radioactive label is performed. 3 Presently, SLNB has become the standard over the axillary lymph node dissection (ALND) in the staging of the axilla for clinically node negative disease because of its accuracy and limited morbidity and invasiveness. 9 In the molecular level, the mechanism that determines sentinel lymph node status involves antigen presenting cells and their ability to uptake macromolecular tracers. then applied sentinel lymph node mapping with injected radiotracer using the gamma probe in the treatment of breast cancer in 1993. 6 By the 1970s, it was noticed that some nodes received drainage before others and were termed, the вЂњsentinel node.вЂќ 7 Lymphatic mapping with the purpose of discovering the sentinel node was first described in 1992 for cutaneous melanoma with the use of blue dye by the late Donald Morton. Historically, the concept of a mapping lymphatic drainage began in the 1950s. 4, 5 The sentinel node biopsy (SLNB) has transformed the surgical management of early breast cancer and although it is now the standard of care we continue to explore the utility of the procedure in more controversial areas such as post neoadjuvant therapy, explore information about the host response to cancer, and test new refined reagents to better identify lymph nodes with metastatic cancer as well. 3 Its relatively low false negative rate of 5 to 10% and high sensitivity rate of 90 to 95% in the detection of cancer to the lymph node basin has made this minimally invasive operation a standard.

1, 2 By definition, the sentinel lymph node is frequently the first node in the lymphatic basin that receives drainage from an anatomic region and is immunologically responsible for that region. Other tests, such as a culture, genetic tests, or immunological tests, may be done on the lymph node sample.The status of the axillary lymph nodes is one of the strongest prognostic factors in women with early stage breast cancer, and the sentinel lymph node biopsy (SLNB) has become the standard of care in the assessment of metastatic spread to the lymph node basin. If a sentinel node is positive for cancer cells, more surgery may be needed to remove more lymph nodes. The lymph node can be taken out, cut into very thin slices, and looked at under a microscope at the time of surgery. Your doctor can see the dye or tracer with a special device.

The map can show where the cancer is likely to spread and which lymph node is most likely to have cancer cells. The dye or tracer makes a map pattern of lymphatic fluid. The dye or tracer moves to the first lymph node (sentinel node) that drains close to the cancer site. Your doctor injects a blue dye or special tracer substance or both into the area around the original cancer site.

For example, the sentinel node (SN) for breast cancer is normally one of the lymph nodes under the arm. The sentinel lymph node is the first node in a group of nodes in the body where cancer cells may move to after they have left the original cancer site and started to spread. But if cancer is found in the sentinel lymph node at the time of surgery, more surgery may be needed to remove additional lymph nodes. A sentinel node biopsy may be done instead of a more extensive surgery called lymph node dissection.

A sentinel node biopsy is used to see if a known cancer has spread from the original cancer site. A sentinel lymph node biopsy is a surgery that takes out lymph node tissue to look for cancer.

Sentinel node biopsy