Importance of Fluorescence Imaging for Minimally Invasive Cancer Surgery

Surgery is one of the important modalities of treatment for cancers arising from gastrointestinal tract. With the advent of technology, minimally invasive surgery (MIS) is found to be both feasible and safe. The primary goal of abdominal cancer surgery, whether open or MIS is to achieve adequate radicality at the safe surgery. Also, evidence is emerging that few early-stage malignancies can be treated with organ conservation and limited lymphadenectomy. Limitations in MIS to achieve all this are identification of tumor locations and to differentiate between viable and nonviable tissues. Optical systems that have near infrared (NIR) imaging, have clinical applications like checking perfusion status of different organs (e.g., colonic segment in colectomy, liver segments in hepatectomy, gastric conduit in esophagectomy), to identify vital structures (e.g., bile duct anatomy, thoracic duct, ureters), detect tumor tissue (liver SOLs like secondaries, peritoneal metastases), and to guide lymph node dissection (sentinel lymph node and radical lymphadenectomy). Some of these uses have shown to be clinically important in practice while others are not that clinically relevant. As most of the newer optical systems have integrated NIR technology, it will be widely available. Also, the most commonly used dye is indocyanine green (ICG), which is not very tissue-specific, availability of compounds that can target tissue of interest can widen the practical use of this technology.