BUENOS AIRES--The surgical care of the melanoma patient is in flux because of new data showing that complete nodal staging can be obtained with the technique of lymphatic mapping and sentinel lymph node biopsy, said speakers at a plenary session at the Sixth World Congress on Cancers of the Skin.
Douglas Reintgen, MD, of the Moffitt Cancer Center, Tampa, Fla, explained that the concept is based on the belief that lymphatic drainage is not a random event, but that the precise node that drains an area of skin can be identified.
The sentinel lymph node is defined as the first node in the lymphatic basin into which the primary melanoma drains, and reports from four centers (John Wayne Cancer Institute, Moffitt Cancer Center, M.D. Anderson Cancer Center, and the Sydney Melanoma Unit) have shown that the histology of the sentinel lymph node reflects the histology of the remainder of the nodal basin.
With the lymphatic mapping technique, only patients with solid evidence of nodal metastatic disease, those with a positive sentinel lymph node, are subjected to the expense and morbidity of a complete node dissection.
This strategy of selective lymphadenec-tomy would seem to satisfy both the proponents and critics of the previous nodal staging procedure--elective lymph node dissection. All patients would undergo complete pathologic staging of their lymphatic basins, and most would be spared a complete lymph node dissection.
The first step with this technique involves lymphatic mapping via preop-erative lymphoscintigraphy--the injection of a radiocolloid around the primary melanoma site--with imaging of the afferent lymphatics and the regional nodal basin (see figure).
Intraoperative lymphatic mapping to harvest the sentinel lymph node for biopsy is then performed using either a vital blue dye or a radiocolloid.