A prospective multi-institutional trial examining the feasibility, accuracy and learning curve of fluorescence imaging for sentinel node localization in melanoma

Abstract

Background

Sentinel node biopsy is a standard component of staging for patients with melanoma. Lymphoscintigraphy with technetium99 (^99mTc) is highly reliable but not patient centered, requiring a separate visit to radiology and often a painful injection. We assessed intra-operative real-time fluorescence lymphangiography as an alternative to ^99mTc for sentinel node localization in patients with extremity melanoma.

Methods

A multi-center single arm prospective trial was conducted for patients with extremity melanoma. All subjects had lymphoscintigraphy with ^99mTc prior to surgery and a dermal injection of indocyanine green in the operating room. The surgeon was blinded to the lymphoscintigraphy results and used real-time fluorescence imaging to localize the sentinel nodes. Success rate and operative times were recorded.

Results

Four surgeons enrolled 35 subjects with melanoma of the upper or lower extremity, excluding hands and feet, who met criteria for sentinel node biopsy based on NCCN guidelines. Each surgeon enrolled at least 8 subjects. The overall success rate for the first sentinel node was 83 % (29/35). The success rate varied between the axilla and groin, and between first, second and third sentinel nodes. The average time to identify the first sentinel node was 14 min, with no consistent improvement over time. There were no complications related to the ICG.

Conclusions

The success rate of sentinel node localization with indocyanine green and fluorescence imaging is high, but not high enough to use this method alone. ICG can safely replace blue dye. The learning curve for this technique is likely more than 8 patients.

Synopsis

ICG and fluorescence imaging may aid in sentinel node localization but should not replace lymphoscintigraphy with ^99mTc. ICG with fluorescence imaging can safely replace blue dye. The learning curve for this technique is at least 8 patients.