USE OF NEAR-INFRARED FLUORESCENCE WITH INDOCYANINE GREEN IN SMALL ANIMAL SURGICAL ONCOLOGY AND IN CADAVERIC ANATOMICAL STUDY

Near-Infrared Fluorescence (NIRF) imaging is an emerging technology that enables real-time visualization of tissue perfusion and lymphatic structures through the use of fluorescent dyes such as indocyanine green (ICG). Although well-established in human surgery, its clinical application in veterinary surgical oncology is still developing. In recent years, however, interest in this technique has grown rapidly, highlighting its potential to improve surgical precision and intraoperative decision-making in small animal surgical oncology. This PhD project investigates the use of NIRF-ICG imaging to address key challenges in surgical oncology in dogs and cats. The research is structured into three main lines of investigation: 1. the use of NIRF-ICG for sentinel lymph node (SLN) identification and removal 2. the application of real-time tumor fluorescence-guided surgery (TFGS) for intraoperative decision-making regarding surgical margins 3. the use of NIRF-ICG lymphography in cadavers to support anatomical studies. In the first research line, NIRF-ICG demonstrated comparable performance to the other guided technique in detecting SLNs, lymphoscintigraphy. These findings support the incorporation of NIRF-ICG into routine clinical practice as a reliable and effective tool for lymphatic mapping in small animal oncology. Moreover, the guidance of NIRF-ICG and lymphoscintigraphy may help address the diagnostic challenge of enlarged regional lymph nodes, providing insights into lymphatic drainage alterations in such cases. The second aim explored the clinical application of TFGS using NIRF-ICG in dogs with soft tissue sarcomas (STS) and mast cell tumors (MCT). The study confirmed the feasibility of the technique in both tumor types, with significantly higher performance observed in STS. These results highlight the potential of intraoperative, real-time fluorescence quantification to guide surgical decisions and enhance tumor resection outcomes in clinical practice. Lastly, the project demonstrated the feasibility of NIRF-ICG lymphography in feline cadavers within an anatomical surgical study. The technique was successfully applied to selected superficial regions of the head and hind limbs of the cat. The use of consistent anatomical landmarks appears promising in improving mapping reliability. In conclusion, the integration of NIRF-ICG imaging into small animal surgical oncology represents a significant step forward for advancing surgical oncology and intraoperative guidance. Beyond its current applications, the technique offers valuable research opportunities across multiple areas of small animal surgical oncology and may support the development of image-guided and minimally invasive approaches, bridging the gap between veterinary and human surgical oncology.