Radioguided surgery for the ultrastaging of the patient with melanoma

Abstract

Purpose: Lymphatic mapping techniques have changed the standard of surgical care for the malignant melanoma population and are being investigated to improve the staging and decrease the morbidity of patients with all types of cancer. This study aimed to describe a combination of techniques and the use of multiple disciplines for accurately staging and treating patients with melanoma.

Materials and methods: Over a 4-year period, 595 patients were studied using a protocol consisting of preoperative lymphoscintigraphy using filtered technetium sulfur colloid to define all regional basins at risk for metastatic disease, and intraoperative lymphatic mapping with a vital blue dye and radiocolloid to identify the node in the basin most at risk for metastases (the sentinel lymph node). Detailed pathological exam (serial sectioning, immunohistochemical staining, reverse transcriptase polymerase chain reaction [RT-PCR] analysis) of the sentinel lymph node was used to stage the melanoma patient.

Results: A combination of blue dye and radiocolloid intraoperative mapping resulted in a 98% success rate for the identification of the sentinel lymph node. Routine pathological examination identified 73.8% of the metastases. The remainder were detected with serial sectioning (7.8%) and immunohistochemical staining (18.4%). RT-PCR analysis based on a tyrosinase probe has upstaged 47% of the histologic sentinel lymph node-negative population.

Conclusion: Lymphatic mapping technology provides accurate staging of the melanoma patient, at lower costs for the health care system and a lower morbidity for the patient.