How Fluorescence Endoscopy Camera Systems Are Rewriting the Standards of Tumor Surgery

For many years, surgeons have made extensive use of white-light endoscopy to view tumors and maneuver surgical tools. However, white-light endoscopy has a major limitation; while providing anatomical information, it does not give biochemical information about the tissues being viewed. This can lead to surgeons making mistakes during tumor resection since the tumor may look grossly normal to the surgeon, or healthy tissue may look grossly abnormal. A critical distinction can be made between simply visualizing a tumor and visualizing the tumor clearly enough to know that it has been successfully removed. With the advent of fluorescence-guided surgery utilizing indocyanine green and near infrared imaging, tumor identification, dissection and localization are set to change forever, with fluorescence endoscopy cameras playing a major role in the transformation.

 

The Technology: Making the Invisible Visible

Fluorescence endoscopy cameras offer a combined approach, as they allow to simultaneously perform standard high-resolution white-light imaging and detect near-infrared (NIR) fluorescence signal. The working principle of such devices is rather simple. A fluorescent substance (mostly indocyanine green, ICG) is injected into the patient's bloodstream, where it selectively accumulates in particular tissues. Once excited by the light in the visible spectrum (usually, 760-785 nm), ICG emits infrared light (820-830 nm), which is then captured by a specialized endoscope camera. Thanks to this technology, one can overlay the fluorescence signal on the white-light image in real-time.

The key advantage of using this technology lies in the possibility to see beyond the visible spectrum. As ICG preferentially accumulates in blood vessels, it allows to estimate the regional blood flow and, consequently, the tissue perfusion. However, tumor tissues often demonstrate altered vascular permeability and lymphatic drainage, which can be used to differentiate malignant and healthy tissues. Thus, the fluorescence endoscopy enables cancer surgeons to accomplish the most critical steps of tumor resection with better precision and safety.

The modern fluorescence endoscopy systems, such as the latest 4K endoscopes provide excellent visualization of the surgical site while allowing to switch from standard white-light mode to the fluorescence mode. Moreover, some video endoscopes are capable of simultaneously capturing and displaying both types of imaging. This way, a surgeon can easily alternate between the modes or use the information from both simultaneously to accomplish the task at hand.

 

Clinical Applications: Transforming Surgical Oncology

The clinical value of fluorescence guidance during surgery is best demonstrated in the field of hepatobiliary surgery, where indocyanine green (ICG) fluorescence plays a critical role in the resection of liver tumors. ICG accumulates in hepatocellular carcinoma tissue, allowing for identification of tumor margins by its characteristic fluorescence. This technology enables more accurate anatomical resections and facilitates the preservation of healthy liver tissue, which is of utmost importance for patients with reduced liver function due to hepatic insufficiency.

In gastric cancer surgery, fluorescence-guided sentinel lymph node mapping is used to determine the tumor's lymphatic drainage area. This technique allows for identification of the first lymph nodes subject to tumor infiltration. As a result, surgeons can perform more accurate lymph node dissection to ensure complete tumor removal in early stages of the disease, thereby reducing the extent of surgery and improving patient outcomes.

Furthermore, fluorescence-guided surgery has been adopted in colorectal surgery, where it is used to assess the integrity of anastomosis. The status of the anastomotic region is one of the most important factors affecting post-surgery complications. By evaluating the fluorescent properties of anastomosis, surgeons can determine its approximate condition and make informed decisions regarding the resection margins and the surgery's further course, ultimately reducing the risk of anastomotic leakage by 30-50% in some cases.

The clinical applications of fluorescence-guided liver surgery extend beyond hepatobiliary diseases, as it may also be used in other tumor-related surgeries. For instance, this technique offers sentinel node biopsy and assessment of tissue perfusion after mastectomy in breast cancer surgery. Moreover, it enables sentinel node detection in urological tumor surgery and improves the accuracy of lymphadenectomy in gynecological cancer surgeries. Finally, fluorescence-guided surgery allows for detection of peritoneal cancer metastases in gynecological oncology.

 

From "Visible" to "Actionable": The Clinical Decision-Making Paradigm Shift

The true value of fluorescence endoscopy lies beyond the improved visualization of anatomical structures during surgery, as it has an effect on the decision-making process itself. Traditional forms of cancer surgery involve pre-surgical staging and imaging (CT, MRI, PET) and assessment of localized structures during surgery; all of these are indirect and non-instantaneous methods. Fluorescence imaging allows acquiring information directly during surgery, enabling the surgeon to make better choices in real time.

Take liver metastases as an example. Pre-surgical imaging can show a number of metastatic lesions in the liver, and surgeons remove them all. However, both intra-operative palpation and ultrasound imaging can find additional small metastases that were not seen on pre-surgical imaging. Fluorescence imaging provides a better chance at visualizing all of the small secondary growths, which leads to more tissue being removed during surgery. The importance of this lies in the concept of R0 resection, or the complete removal of cancerous tissue; this is an important indicator of survival and quality of life after cancer.

A similar consideration is made when assessing the margins of surgically removed tissue. In many cases, fluorescence imaging allows determining the oncological safety of margins during surgery, which means that the surgeon can make adjustments immediately if needed. This can eliminate the need for additional surgery when assessing margins using traditional methods such as frozen section analysis.

 

Challenges and Considerations

Despite the advantages of fluorescence-guided surgery, there are several disadvantages. Fluorescence imaging technology presents several challenges, including the need for standardized dosing and timing of indocyanine green (ICG) injections, optimal settings of fluorescence visualization, and surgeon experience and education. Currently, there are discrepancies in ICG regimens between institutions and even within individual facilities depending on the procedure. Ideally, the dose should be adjusted to maximize contrast while minimizing background "noise," and the timing of the injection is critical and depends on the tissue type being imaged. Moreover, the interpretation of fluorescence findings often requires familiarity with the technology and an understanding of its limitations, such as the fact that not all malignant tumors exhibit increased fluorescence, whereas some normal tissues do. At the same time, false-positive findings can sometimes be seen in inflammatory conditions, and false-negative results might occur if tumor tissue is poorly vascularized. Thus, education and training are also important components of this technology.

Furthermore, the cost and availability of the equipment and ICG can be prohibitive, at least initially. Fluorescence endoscopy cameras are expensive pieces of equipment, whereas ICG is currently considered a luxury. However, it is anticipated that the cost of equipment will decrease due to increased competition in the market and the availability of fluorescence endoscopes will soon be more widespread, although it will initially be concentrated in large medical centers.

 

The 2026 Landscape and Beyond

As of 2026, fluorescence endoscopy has transitioned from a novel tool to a standard practice in many areas of surgical oncology. Combined with the advances in 4K and 3D endoscopy visualization, fluorescence forms part of an integrated platform that addresses a broad range of surgical indications. Analysts are forecasting further adoption fueled by an expanding evidence base and opportunities for codevelopment with complementary technologies.

Several promising innovations are disrupting the field at an accelerating pace. On the clinical front, new targeted fluorescent agents capable of binding to specific receptors on tumor cells appear to have significant potential to surpass indocyanine green in terms of tumortissue specificity. Researchers are currently evaluating various ligands targeting folate receptors, EGFR, and PSMA, among others.

Meanwhile, on the technical front, fluorescence image analysis is being revolutionized by the incorporation of machine learning algorithms that can discern relevant information from irrelevant information, identify patterns too subtle for the human eye to detect, and even classify tumors based on their fluorescence patterns. A growing body of evidence is beginning to suggest that employing artificial intelligence to interpret surgical fluorescence imaging can eliminate much of the guesswork typically involved in fluorescence-guided surgery, allowing even minimally experienced surgeons to perform as well as their more experienced peers.

Looking ahead, the combination of fluorescence endoscopy with other cutting-edge technologies, including augmented reality surgical navigation and robotic-assisted surgery, has the potential to create synergies that lead to a fully integrated ecosystem where numerous disparate forms of information get combined into a coherent, unified picture. Such a system could enable the surgeon to simultaneously visualize and interpret multiple forms of data, including robotic-assisted dissection, relevant preoperative imaging, fluorescence imaging, and even intraoperative ultrasound, with enhanced ease and accuracy.

The transition from white-light endoscopy to fluorescence-guided surgery is indeed revolutionary, but not only because of the technological advances. With it comes the paradigm shift in cancer surgery from an anatomical to a biological approach. The surgeon can now see beyond anatomy and visualize function and biochemistry. The challenges of margin assessment and perfusion monitoring are met with new opportunities for objective assessment and intraoperative feedback. Most importantly, the clinical uncertainty about achieving complete resection is replaced by immediate visual confirmation of tumor-free resection.

The fluorescence endoscopy camera systems have enabled that transition and will continue to do so in the future as the field moves toward targeted probes, artificial intelligence, and multimodal systems. In this respect, the present work is only one step in a much larger journey that will lead to enhanced therapeutic efficacy and ultimately more patients cured of cancer.