In 1994, Giuliano and co-workers published their initial work of intraoperative lymphatic mapping with a vital blue dye . A 1% isosulfan blue dye solution (Lymphazurin, Hirsh Industries, Inc., Richmond, VA, U.S.A.) was used to identify the sentinel node in this study of 172 patients (174 lymph node basins). The sentinel node was identified in 66% of patients overall, but the identification rate improved as the investigator became familiar with the nuances of the technique. The 59% rate of sentinel node detection in the first 87 cases increased to 72% in the next 87 cases and the detection rate reached 78% by the last 50 cases in this series. The technique was modeled after the melanoma model, a cutaneous tumor, but had to be adapted to breast cancer, which is a parenchymal tumor. This led to significant changes in the technique. In this study, there were five false-negative cases reported in which the pathology of the sentinel node did not accurately predict the status of the axilla. All false negatives occurred in the first 87 cases. This was a critical problem with the technique because a false-negative result could potentially lead to the undertreatment of a node-positive patient. These five cases were reanalyzed and it was discovered that in three of the five cases, axillary fat was misidentified as the sentinel node. This prompted the use of intraoperative frozen section to confirm the presence of nodal tissue. A fourth patient was found to have occult metastasis when the pathology was reevaluated with immunohistochemical stains using anticytokeratin antibodies. With our current histopathological workup, involvement of the sentinel node would have been identified. Only one of the five patients examined had a ''true'' false-negative sentinel node improving the accuracy rate from 96% to 99%.
The initial modest identification rate of 66% is, in retrospect, interpreted as the ''learning curve.'' Although we do feel that experience is needed before mastering this technique, many of the problems during this learning curve are now avoided due to improvements in the technique itself as well as better patient selection. The volume of dye injected, the site of injection, the timing of the axillary incision, the histopathological workup of the sentinel node and the addition of massage to the injection site all aided in improving the probability of identifying the sentinel node. Using this mature technique in a subsequent study, the sentinel node was identified in 93% of patients and was 100% predictive of the nodal status . Based on the results of this study, we abandoned completion axillary lymph node dissection in 1995 in patients whose sentinel nodes were tumor-free.
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Complete Guide to Preventing Skin Cancer. We all know enough to fear the name, just as we do the words tumor and malignant. But apart from that, most of us know very little at all about cancer, especially skin cancer in itself. If I were to ask you to tell me about skin cancer right now, what would you say? Apart from the fact that its a cancer on the skin, that is.