Short-Wave Infrared Fluorescence-Guided Surgery Using Indocyanine Green in a Dog with a Cutaneous Mast Cell Tumor

A 6-year-old spayed, female golden retriever dog was presented with a skin mass on the dorsal region of the right carpus. The cytology result of the region revealed characteristics of mast cell tumors (MCTs). Short wave-infrared fluorescence-guided surgery using Indocyanine green (ICG) was performed to determine the surgical margin of the tumor. ICG was injected intravenously 24 hours before the surgery and the patient was hospitalized and carefully monitored. During the surgery, ICG fluorescence-based surgery was performed to identify the tumor and the surgical margin. The tumor was visible, and the skin mass was resected using NIR device for the guidance of the surgical margin of the tumor. Once the resection was complete, the surgical site was again inspected with SWIR fluorescence imaging to identify residual tumor cells. The resected tumor, using ICG navigation, was classified as low-grade cutaneous MCT and the margin was complete on the histopathological result. We report herein a case of resection of a cutaneous MCT in a dog using SWIR fluorescence imaging ICG which can be potentially used for the identification of tumors and evaluation of the surgical margin for complete resection.