The iGreenGO Study: The Clinical Role of Indocyanine Green Imaging Fluorescence in Modifying the Surgeon's Conduct During the Surgical Treatment of Advanced Gastric Cancer-Study Protocol for an International Multicenter Prospective Study

The role of ICG NIRL fluorescence imaging in the surgical treatment of digestive system tumors (Review)

Indocyanine green (ICG) is a relatively non‑toxic fluorescent dye with a history of safe use, which has fueled the development of new applications for ICG. Research on the use of ICG near‑infrared light (NIRL) fluorescence imaging during oncologic surgery has increased, revealing its role in tumor identification and localization, lymph node navigational resection and blood perfusion assessment. The purpose of the present review was to provide a comprehensive overview of advances in the clinical application of ICG NIRL fluorescence imaging during gastrointestinal tumor surgery. The present review discusses the techniques, outcomes, limitations and key considerations necessary for clinical practice, aiming to provide a valuable resource for professionals in the field.

Potential Probes for Targeted Intraoperative Fluorescence Imaging in Gastric Cancer

Gastric cancer (GC) is a malignant tumor of the gastrointestinal tract associated with high mortality rates and accounting for approximately 1 million new cases diagnosed annually. Surgery, particularly radical gastrectomy, remains the primary treatment; however, there are currently no specific approaches to better distinguish malignant from healthy tissue or to differentiate between metastatic and non-metastatic lymph nodes. As a result, surgeons have to remove all lymph nodes indiscriminately, increasing intraoperative risks for patients and prolonging hospital stay. Near-infrared fluorescence imaging with indocyanine green (ICG) can provide real-time visualization of the surgical field using both conventional laparoscopy and robotic mini-invasive precision surgery platforms. However, its application shows some limits, as ICG is a non-targeted contrast agent. Several studies are now investigating the potential efficacy of fluorescent targeted agents that could selectively bind to the tumor tissue, offering a valuable tool for metastatic mapping during robotic gastrectomy. This review aims to summarize the key fluorescent agents that have been developed to recognize GC markers, as well as those targeting the tumor microenvironment (TME) and metabolic features. These agents hold great potential as valuable tools for enhancing precision surgery in robotic gastrectomy procedures improving the clinical recovery of GC patients.

Sentinel Node Navigation Surgery for Early Gastric Cancer: A Narrative Review

Early gastric cancer (EGC) refers to malignant tumor lesions that are limited to the mucosa and submucosa layers, regardless of the presence of lymph node metastasis. Typically, EGC has a low rate of perigastric lymph node metastasis, and long-term survival outcomes are good after radical surgical treatment. The primary objective of surgical treatment for EGC is to achieve functional preservation while ensuring a radical cure. Sentinel node navigation surgery (SNNS) is a surgical technique used in the treatment of EGC. This approach achieves functional preservation by limiting lymph node dissection and performing restrictive gastrectomy guided by intraoperative negative sentinel node (SN) biopsy. Despite the apparent improvement in the detection rate of SN with the emergence of various tracing dyes and laparoscopic fluorescence systems, the oncological safety of SNNS remains a controversial research topic. SNNS, as a true form of stomach preservation surgery that enhances the quality of life, has become a topic of interest in the EGC field. In recent years, scholars from Japan and South Korea have conducted extensive research on the feasibility and safety of SNNS in the treatment of EGC. This article aims to provide reference choices for surgeons treating EGC by reviewing relevant research on SNNS for EGC in recent years.

Indocyanine green fluorescence imaging-guided versus conventional laparoscopic lymphadenectomy for gastric cancer: long-term outcomes of a phase 3 randomised clinical trial

Indocyanine green (ICG) fluorescence imaging-guided lymphadenectomy has been demonstrated to be effective in increasing the number of lymph nodes (LNs) retrieved in laparoscopic gastrectomy for gastric cancer (GC). Previously, we reported the primary outcomes and short-term secondary outcomes of a phase 3, open-label, randomized clinical trial (NCT03050879) investigating the use of ICG for image-guided lymphadenectomy in patients with potentially resectable GC. Patients were randomly (1:1 ratio) assigned to either the ICG or non-ICG group. The primary outcome was the number of LNs retrieved and has been reported. Here, we report the primary outcome and long-term secondary outcomes including three-year overall survival (OS), three-year disease-free survival (DFS), and recurrence patterns. The per-protocol analysis set population is used for all analyses (258 patients, ICG [n = 129] vs. non-ICG group [n = 129]). The mean total LNs retrieved in the ICG group significantly exceeds that in the non-ICG group (50.5 ± 15.9 vs 42.0 ± 10.3, P < 0.001). Both OS and DFS in the ICG group are significantly better than that in the non-ICG group (log-rank P = 0.015; log-rank P = 0.012, respectively). There is a difference in the overall recurrence rates between the ICG and non-ICG groups (17.8% vs 31.0%). Compared with conventional lymphadenectomy, ICG guided laparoscopic lymphadenectomy is safe and effective in prolonging survival among patients with resectable GC.

Global trends in indocyanine green fluorescence navigation in the field of gastric cancer: bibliometrics and knowledge atlas analysis

Background

Indocyanine green (ICG) fluorescence navigation can enhance the visualization of gastric cancer (GC) lesions, increase the lymph node detection rate, and reduce the incidence of anastomotic leakage in the treatment of GC. It thus holds considerable potential for application in GC clinical surgery and has attracted widespread research interest. The purpose of this study was to visualize the current topics and emerging trends in research regarding ICG in GC.

Methods

We searched the Web of Science Core Collection (WoSCC) for articles relevant to the use of ICG in GC. The resulting information was then analyzed from a bibliometric and knowledge graph analysis perspective using CiteSpace, Scimago Graphica, and R Studio so that the key trends and hot spots in research within this field could be identified and visualized.

Results

Ultimately, 1,385 papers from 58 countries or regions published from 1991 to 2022 were included in this study. The largest number of publications were from China, followed by Japan and the United States. High-yield institutions were concentrated in Asian countries, especially China. The top publication contributors were Shanghai Jiao Tong University. Li Y and Bang YJ ranked first among the top 10 most productive authors and top 10 most cocited authors, respectively. World Journal of Gastroenterology was the most productive academic journal on ICG in GC, while Cancer Research was the most commonly cocited journal. The keyword "indocyanine green" was among the top 5 keywords, and will likely remain a popular topic in future research. Furthermore, the emerging themes including surgery, biopsy, lymphadenectomy, dissection, and gastrectomy have attracted increasing attention.

Conclusions

Current research hotspots in this area focus on the clinical implementation of ICG in precision surgery for GC. Given the imaging tracer characteristics of ICG and its utility in GC surgery, the optimization and application of ICG-guided precision surgery techniques for GC will be a research hot spot going forward.

Indocyanine green dye and its application in gastrointestinal surgery: The future is bright green

Indocyanine green (ICG) is a water-soluble fluorescent dye that is minimally toxic and widely used in gastrointestinal surgery. ICG facilitates anatomical identification of structures (e.g., ureters), assessment of lymph nodes, biliary mapping, organ perfusion and anastomosis assessment, and aids in determining the adequacy of oncological margins. In addition, ICG can be conjugated to artificially created antibodies for tumour markers, such as carcinoembryonic antigen for colorectal, breast, lung, and gastric cancer, prostate-specific antigen for prostate cancer, and cancer antigen 125 for ovarian cancer. Although ICG has shown promising results, the optimization of patient factors, dye factors, equipment, and the method of assessing fluorescence intensity could further enhance its utility. This review summarizes the clinical application of ICG in gastrointestinal surgery and discusses the emergence of novel dyes such as ZW-800 and VM678 that have demonstrated appropriate pharmacokinetic properties and improved target-to-background ratios in animal studies. With the emergence of robotic technology and the increasing reporting of ICG utility, a comprehensive review of clinical application of ICG in gastrointestinal surgery is timely and this review serves that aim.