Time to maximum indocyanine green fluorescence of gastric sentinel lymph nodes and feasibility of combined indocyanine green/sodium fluorescein gastric lymphography

Current status and future trends of real-time imaging in gastric cancer surgery: A literature review

Technological advances are crucial for the optimization of gastric cancer surgery, and the success of any gastric cancer surgery is based on the correct and precise anatomical determination of the primary tumour and tissue structures. Real-time imaging-guided surgery is showing increasing potential and utility, mainly because it helps to aid intraoperative decision-making. However, intraoperative imaging faces many challenges in the field of gastric cancer. This article summarizes and discusses the following clinical applications of real-time optical imaging and fluorescence-guided surgery for gastric cancer: (1) the potential of quantitative fluorescence imaging in assessing tissue perfusion, (2) vascular navigation and determination of tumour margins, (3) the advantages and limitations of lymph node drainage assessment, and (4) identification of peritoneal metastases. In addition, preclinical study of tumour-targeted fluorescence imaging are discussed.

Mapping Lymph Node during Indocyanine Green Fluorescence-Imaging Guided Gastric Oncologic Surgery: Current Applications and Future Directions

Huge strides have been made in the navigation of gastric cancer surgery thanks to the improvement of intraoperative techniques. For now, the use of indocyanine green (ICG) enhanced fluorescence imaging has received promising results in detecting sentinel lymph nodes (SLNs) and tracing lymphatic drainages, which make it applicable for limited and precise lymphadenectomy. Nevertheless, issues of the lack of specificity and unpredictable false-negative lymph nodes were encountered in gastric oncologic surgery practice using ICG-enhanced fluorescence imaging (ICG-FI), which restrict its application. Here, we reviewed the current application of ICG-FI and assessed potential approaches to improving ICG-FI.

Efficacy of indocyanine green fluorescence imaging-guided lymphadenectomy in radical gastrectomy for gastric cancer: A systematic review and meta-analysis

Background

Indocyanine green (ICG) imaging-guided lymphadenectomy has been introduced in gastric cancer (GC) surgery and its clinical value remains controversial. The aim of this study is to evaluate the efficacy of ICG fluorescence imaging-guided lymphadenectomy in radical gastrectomy for GC.

Methods

Studies comparing lymphadenectomy in radical gastrectomy between use and non-use of ICG fluorescence imaging up to July 2022 were systematically searched from PubMed, Web of Science, Embase and Cochrane Library. A pooled analysis was performed for the available data regarding the baseline features, the number of retrieved lymph nodes (LNs), the number of metastatic LNs and surgical outcomes as well as oncological outcomes. RevMan 5.3 software was used to perform the statistical analysis. Quality evaluation and publication bias were also conducted.

Results

17 studies with a total of 2274 patients (1186 in the ICG group and 1088 in the control group) undergoing radical gastrectomy and lymphadenectomy were included. In the pooled analysis, the baseline features were basically comparable. However, the number of retrieved LNs in the ICG group was significantly more than that in the control group (MD = 7.41, 95% CI = 5.44 to 9.37, P < 0.00001). No significant difference was found between the ICG and control groups in terms of metastatic LNs (MD = -0.05, 95% CI = -0.25 to 0.16, P = 0.65). In addition, the use of ICG could reduce intraoperative blood loss (MD = -17.96, 95% CI = -27.89 to -8.04, P = 0.0004) without increasing operative time (P = 0.14) and overall complications (P = 0.10). In terms of oncological outcomes, the use of ICG could reduce the overall recurrence rate (OR = 0.50; 95% CI 0.28-0.89; P = 0.02) but could not increase the 2-year overall survival rate (OR = 1.25; 95% CI 0.72-2.18; P = 0.43).

Conclusions

ICG imaging-guided lymphadenectomy is valuable for complete LNs dissection in radical gastrectomy for GC. However, more high-quality randomized controlled trials are needed to confirm this benefit.

Exosomal hsa_circ_0017252 attenuates the development of gastric cancer via inhibiting macrophage M2 polarization

Gastric cancer (GC) is an aggressive malignant tumor of the digestive system, with high morbidity rates. We previously demonstrated that miR-17-5p can modify tumorigenesis in GC. In addition, other studies have shown that circRNAs can regulate GC progression by sponging various miRNAs. However, the association between circRNAs and miR-17-5p in GC has not yet been explored. Hence, this study aimed to explore the possible interactions between various circRNAs and miR-17-5p using a dual-luciferase assay. CCK-8 was used to determine cell viability, and a Transwell assay was used to measure cell invasion and migration. Gene expression was assessed using quantitative reverse transcription PCR (RT-qPCR), and exosomes were identified using transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Annexin V/PI staining was also used to detect cell apoptosis. These investigations collectively revealed that miR-17-5p is a target of the circRNA hsa_circ_0017252 and hsa_circ_0017252 is significantly downregulated in GC tissues. In addition, the overexpression of hsa_circ_0017252 inhibited GC cell migration by sponging of miR-17-5p, and GC cell-secreted exosomal hsa_circ_0017252 effectively inhibited macrophage M2-like polarization, which in turn suppressed GC cell invasion. Notably, exosomes containing hsa_circ_0017252 also suppressed GC tumor growth in vivo. Thus, our data suggest that the overexpression of hsa_circ_0017252 suppresses GC malignancy by sponging miR-17-5p. In addition, exosomal hsa_circ_0017252 excreted from GC cells attenuated GC progression by suppressing macrophage M2-like polarization. These findings improve our basic understanding of GC and open a novel avenue for developing more effective GC treatments.

The Use of Indocyanine Green (ICG) and Near-Infrared (NIR) Fluorescence-Guided Imaging in Gastric Cancer Surgery: A Narrative Review

Near-infrared fluorescence imaging with indocyanine green is an emerging technology gaining clinical relevance in the field of oncosurgery. In recent decades, it has also been applied in gastric cancer surgery, spreading among surgeons thanks to the diffusion of minimally invasive approaches and the related development of new optic tools. Its most relevant uses in gastric cancer surgery are sentinel node navigation surgery, lymph node mapping during lymphadenectomy, assessment of vascular anatomy, and assessment of anastomotic perfusion. There is still debate regarding the most effective application, but with relatively no collateral effects and without compromising the operative time, indocyanine green fluorescence imaging carved out a role for itself in gastric resections. This review aims to summarize the current indications and evidence for the use of this tool, including the relevant practical details such as dosages and times of administration.