Skin melanoma sentinel lymph node biopsy using real-time fluorescence navigation with indocyanine green and indocyanine green with human serum albumin

Funding sources: none. Conflicts of interest: none declared. Madam, To date sentinel lymph node (SLN) biopsy (SLNB) remains a standard procedure in the evaluation of regional lymphatic flow and to assess the stage of cutaneous malignant melanoma (CMM). Currently radioactive colloid (RC) and/or blue dye are predominantly used for this procedure. However, with the advent of near infrared (NIR) technology, the use of NIR‐guided fluorophores has emerged as an alternative method and has garnered much interest in various cancer settings.1–5 In present study, we have utilized this novel method to evaluate real‐time visualization of SLNB in patients with CMM using indocyanine green (ICG) and ICG conjugated to human serum albumin (ICG:HSA) fluorophores and compared it with the RC method. After being approved by the local Ethical Committee, 10 consecutive patients were enrolled for the study between September and December 2010. All provided written consent. Patient details are presented in Table 1. Enrolled patients were then divided into two groups, five of whom received ICG and the other five ICG:HSA. All patients were examined using RC as a standard marker. ICG (Pulsion Medical Systems AG, Munich, Germany) was dissolved in 5 mL sterile water to reach a concentration of 10 mg dL−1. ICG:HSA was prepared by mixing 2·4 mL of the aforesaid ICG solution with 50 mL of 20% HSA (human albumin Grifols 20%; Instituto Grifols SA, Barcelona, Spain) to obtain a concentration of 600 μmol L−1 ICG:HSA; the authors deemed this concentration to be most appropriate on the basis of the study performed by Mieog et al.6 for SLN visualization in breast cancer. One day prior to the surgery, all patients received injections of RC – Tc99m at four intradermal sites surrounding the scar. Similarly but just prior to the commencement of the surgery, 2 mL of ICG or ICG:HSA was injected at four intradermal sites surrounding the scar. Real‐time flow was observed by PDE camera (Photo‐Dynamic‐Eye, Hamamatsu, Japan, distributed by Pulsion Medical Systems AG) when the NIR fluorophore was administered.