A Novel Injection Protocol Using Voluven®-Assisted Indocyanine Green with Improved Near-Infrared Fluorescence Guidance in Breast Cancer Sentinel Lymph Node Mapping—A Translational Study

Background: Near-infrared (NIR) fluorescence-guided surgery with indocyanine green (ICG) has been demonstrated to provide high sensitivity in sentinel lymph node biopsy (SLNB) for breast cancer but has several limitations, such as unstable pharmacokinetics, limited fluorescence brightness, and undesired diffusion to neighboring tissues. This paper investigates the use of Voluven® as the solvent for ICG fluorescence-guided SLNB (ICG-SLNB). Methods: The photophysical properties of ICG in water and Voluven® were evaluated in laboratory experiments and in a mouse model. Nine patients with early breast cancer underwent subareolar injection of diluted ICG (0.25 mg/ml) for ICG-SLNB. Six of the nine patients received ICG dissolved in Voluven® (ICG:Voluven®), while three were administered ICG dissolved in water (ICG:water); a repetitive injection-observation protocol was followed for all patients. The mapping image quality was evaluated. Results: Laboratory experiments and in vivo mouse study showed improved fluorescence and better targeting using Voluven® as the solvent. ICG-SLNB with a repetitive injection-observation protocol was successfully performed in all nine patients. ICG:Voluven® administration had an overall better signal-to-background ratio (SBR) in sequential sentinel lymph nodes. The rates of transportation within the lymphatics were also improved using ICG:Voluven® compared with ICG:water. Conclusions: From basic research to animal models to in-human trial, our study proposes a repetitive injection-observation technique with ICG:Voluven®, which is characterized by better transportation and more stable mapping quality for ICG-SLNB in breast cancer patients.