Evaluating accuracy for identification of sentinel lymph nodes in dogs with cutaneous Mast Cell Tumors; a comparison between preoperative CT lymphography, intraoperative indocyanine green NIRF, and the standard cytology of the locoregional lymph node

Enrollment Status: Currently Enrolling

• Inclusion Criteria: Any dog with a single or multiple cutaneous MCTs (> 1 cm in diameter) diagnosed via cytology or histopathology and undergoing primary tumor(s) surgical excision.
• Treatment: Intraoperative SLN mapping will be performed using a NIRF and MB injection in order to identify the SLNs for removal. These lymph nodes will then be submitted for histopathology and cytology to evaluate for the presence of metastatic disease. The primary tumor will then be surgically removed and submitted for histopathology.
• Cost: There are two arms or groups to this study. Methylene blue will only be used for select cases. If methylene blue is used, the study will cover the cost of CT lymphography, cytology of the locoregional or sentinel lymph nodes, as well as the cost of one indocyanine green injection for intraoperative lymph node mapping, and the NIRF imaging package. This is approximately a value of $1200. If methylene blue is not used, the study will cover the cost of CT lymphography for preoperative lymph node mapping; and cytology of the locoregional or sentinel lymph nodes. This is approximately a value of $800. Histopathology of the lymph nodes and primary tumor will not be covered by the grant.
• Contact: Contact Dr. Judith Bertran at judith@ufl.edu, or complete the Study Interest Form to see if your dog qualifies.
• PI: Judith Bertran

Background: Your dog has been diagnosed with a skin Mast Cell Tumor (MCT), which is the most common skin cancer in the dog. MCTs have the potential to spread throughout the body, or metastasize. When this occurs, they will typically first spread to the primary lymph node that drains lymph from the tumor, also known as the sentinel lymph node (SLN). Removal of the SLN along with the primary tumor can help us to stage your dog’s cancer and may lead to improved survival times if the tumor has spread to the SLN. However, it is difficult to predict which lymph node in the body is the SLN without performing procedures to map the flow of lymphatics from the tumor. The purpose of this study is to evaluate a new method of lymph node mapping (near-infrared fluorescence imaging, NIRF, combined with methylene blue, MB) and determine its accuracy in identifying SLNs in dogs with MCTs. This new method of lymph node mapping maybe easier, faster, and more affordable than the existing options. Determining the utility of combined NIRF and MB injection for SLN mapping may therefore encourage widespread use, which could improve SLN detection and overall outcomes in dogs with MCTs.