Sentinel lymph node

The injection protocols differ by doctor but the most common is a 500 μCi dose divided among 5 tuberculin syringes with 1/2 inch, 24 gauge needles.

A gentle massage of the injection sites spreads the sulphur colloid, relieving the pain and speeding up the lymph uptake.

The surgeon then removes these lymph nodes and sends them to a pathologist for rapid examination under a microscope to look for the presence of cancer.

With malignant melanoma, many pathologists eschew frozen sections for more accurate "permanent" specimen preparation due to the increased instances of false-negative with melanocytic staining.

First and foremost, it decreases lymph node dissections where unnecessary, thereby reducing the risk of lymphedema, a common complication of this procedure.

Increased attention on the node(s) identified to most likely contain metastasis is also more likely to detect micrometastasis and result in staging and treatment changes.

Tumor biology pertaining to metastatic capacity,[19] mechanisms of dissemination, the EMT-MET-process (epithelial–mesenchymal transition) and cancer immunology[20] are some subjects which can be more distinctly investigated.

[24] The technique of sentinel node radiolocalization was co-founded by James C. Alex, MD, FACS and David N. Krag MD (University of Vermont Medical Center) and they were the first ones to pioneer this method for the use of cutaneous melanoma, breast cancer, head and neck cancer and Merkel cell carcinoma.

The first such trial, led by Umberto Veronesi at the European Institute of Oncology, showed that women with breast tumours of 2 cm or less could safely forgo axillary dissection if their sentinel lymph nodes were found to be cancer-free on biopsy.