Background: Sentinel lymph node (SLN) biopsy is the standard care for early detection and staging of lymph node metastasis in melanomas. Radiocolloids (RC) and blue dyes are used for SLN detection. Recently, near infrared (NIR) fluorescence tracing using indocyanine green has been developed as an alternative method for SLN detection. The relatively high tissue penetration depth of several millimeters and the ability to detect low concentrations of tracer both suggest that NIR may have significant advantages over RC and the blue dye methods. The objective of this study was to prospectively compare the performance of all three SLN detection techniques using them sequentially to evaluate the same group of patients.
Methods: One hundred twenty-one primary cutaneous melanoma patients with an indication for SLN biopsy were assigned to the procedure following NIR, blue dye, and RC detection techniques.
Results: No adverse event was reported. SLN was not detected in only 4.1% of cases. In 90.9%, an SLN was identified with NIR, but without any auxiliary technique in only 70.2% of cases. RC detected the SLN in 92.6% of cases. Patent blue was found in the sentinel node in 76.9%. The combination of all three techniques detected an SLN in 95.9% of cases. Metastases were present in 26.7%. The false-negative rate was 8.8%, with a negative predictive value of 91.2%.
Conclusions: RC was the only technique with high SLN detection. Both the blue dye and NIR methods added sensitivity to the detection rate but should not be a substitute for RC.