Last Updated: 2003-01-31 13:45:39 -0400 (Reuters Health)
NEW YORK (Reuters Health) - In nearly 20% of melanoma patients with multiple sentinel lymph nodes (SLN) evident on radioisotope and blue dye mapping, the node with the highest isotope count does not contain metastases, results of a new study indicate.
Based on this finding, "all blue-stained nodes as well as nodes that contain at least 10% of the isotope count of the hottest node should be harvested to detect nodal metastases," lead author Dr. Ira A. Jacobs, from the University of Illinois at Chicago, told Reuters Health.
"We decided to study this topic because there was no good literature on which nodes should be removed" during SLN biopsy in patients with melanoma, Dr. Jacobs noted.
The study involved 132 patients with melanoma who underwent SLN biopsy. In all cases, the lymph nodes were mapped with a vital blue dye and with a radioisotope. The researchers' findings are published in the January issue of the Archives of Surgery.
More than one SLN was identified in 83 patients, the authors note. Of these patients, 21 had SLNs that contained metastases. In 17 of these patients, the SLN with the highest isotope count contained metastases, while in four patients it did not.
"Neither the presence of blue dye nor isotope ratios of any particular threshold level consistently identified the positive SLN in all patients," the researchers report.
Despite this, Dr. Jacobs believes that the findings may offer some reassurance to clinicians. "The results suggest that it is okay to leave behind nodes with high isotope counts so long as the count does not exceed 10% of the hottest node's count," he added.
Arch Surg 2003;138:63-66.