University of Pennsylvania Cancer Center
Last Modified: May 16, 1999
A technique called "sentinel node mapping" can accurately diagnose the minority of patients whose melanoma has spread, while saving the majority from radical lymph node dissection surgery, according to results of a five-year, multi-center study.
In sentinel node mapping, injections of radioisotope makers and blue dye are used to pinpoint the lymph node or nodes that are the first to collect metastasizing cancer cells. One or two sentinel nodes are removed and examined for evidence of cancer. If no cancer is found, no more nodes are removed; if cancer is found, all nodes within that tumor's lymph basin are removed. In traditional practice, all lymph nodes in the area of a solid tumor are removed, a more radical procedure which can cause impaired motion and nerve damage. Sentinel node mapping has become increasingly popular in breast cancer staging, and is seen as a solution to diagnosing the spread of melanoma, which can occur anywhere on the skin and so can involve different lymph node sites in the neck, armpit or groin.
This study, led by Dr. Donald Morton, compares the experience of using sentinel node mapping for melanoma by physicians at the John Wayne Cancer Institute (JWCI), where the technique was developed, with physicians at 16 other centers who received training in the procedure from JWCI. Results show that if used correctly after adequate training, sentinel node mapping can pinpoint the approximately 80 percent of patients who do not need radical node dissection for melanoma; for those whose melanoma has spread, it can provide an accurate diagnosis of extent of disease and potential for survival.