Safety and efficacy of indocyanine green near-infrared fluorescent imaging-guided lymph nodes dissection during radical gastrectomy for gastric cancer: A systematic review and meta-analysis

Bright and Specific Targeting of Metastatic Lymph Nodes in Orthotopic Mouse Models of Gastric Cancer with a Fluorescent Anti-CEA Antibody

BACKGROUND

Gastric cancer poses a major diagnostic and therapeutic challenge. Improved visualization of tumor margins and lymph node metastases with tumor-specific fluorescent markers could improve outcomes.

METHODS

To establish orthotopic models of gastric cancer, one million cells of the human gastric cancer cell line, MKN45, were suspended in 50 μl of equal parts PBS and Matrigel and injected into the nude mouse stomach with a 29-gauge needle. Tumors were allowed to grow for 8-12 weeks before performing imaging studies. For tumor labeling, M5A (humanized anti-CEA mAb) and IgG as a control, were conjugated with the near-infrared dye IRDye800CW. Mice were randomized to receive 50 μg of M5A-IR800 (n = 14) or 50 μg of IgG-IR800 (n = 14) intravenously and were imaged 72 hours later. Fluorescence imaging was performed using the LI-COR Pearl Imaging System.

RESULTS

Forty-two lymph nodes were collected from 28 mice, of which 59.5% were found to contain metastatic gastric cancer cells on pathologic examination. In mice that received M5A-IR800, there was a statistically significant difference in the mean fluorescence signal for cancer-positive lymph nodes at 0.431 (SE ± 0.224) compared with 0.105 (SE ± 0.009) for cancer-negative nodes (p: 0.002). For IgG-IR800, there was no significant difference in the mean fluorescence signal for cancer-positive nodes (0.057) compared with cancer-negative nodes (0.064), p-value 0.677.

CONCLUSIONS

Humanized anti-CEA (M5A) antibodies conjugated to fluorescent dyes provide bright labeling of lymph nodes containing metastatic gastric cancer. This tumor-specific fluorescent antibody is a promising clinical tool for identifying lymph nodes containing metastatic gastric cancer.

The use of indocyanine green and near-infrared fluorescence in the detection of metastatic lymph nodes during oesophageal and gastric cancer resection: a systematic review and meta-analysis

BACKGROUND

Lymph node status is one of the most important prognosticating factors for patients afflicted by oesophageal cancer (OC) and gastric cancer (GC), and lymphadenectomy during surgery is therefore an essential step to ensure complete oncological resection and accurate disease staging. Intraoperative lymph node visualisation using near-infrared fluorescence (NIRF) and indocyanine green (ICG) tracing has been postulated to improve the overall lymph node yield, and to ensure the appropriate radicality, but its usefulness in the detection of metastatic lymph nodes remains unclear.

METHODS

We conducted a systematic review and meta-analysis of the relevant literature to ascertain the accuracy of ICG-guided lymphadenectomy in the detection of metastatic nodes in OC and GC. The primary outcomes were the sensitivity, specificity and diagnostic odds ratio of ICG-guided lymphadenectomy. Secondary outcomes included measurement of the effect of prior neoadjuvant chemotherapy (NAC), tumour characteristics and method of ICG administration. Summary receiver operator characteristic (SROC) curves were built to illustrate the relationship between the sensitivity of ICG and false positive rate.

RESULTS

From an initial search of 6,302 articles, 15 studies met the criteria for inclusion, incorporating 4,004 patients. The pooled sensitivity for metastatic node detection was 69.1% (95% CI 56.5-79.3%), specificity 47.4% (38.0-56.9%), and DOR 2.02 (1.40-2.92). The SROC curve for diagnostic test accuracy yielded an area under the curve of 0.60. The use of NAC adversely affected the sensitivity of ICG 74.7% [59.2-85.8%] without NAC; 52.8% [43.6-61.9%] with NAC, p = 0.018). No significant difference in efficacy was demonstrated between pathological 'T' stage, or ICG administration method.

CONCLUSION

Our findings suggest that the oncological benefits of NIRF and ICG in the context of lymphadenectomy in OC and GC are limited, and that surgeons risk omitting a significant proportion of metastatic nodes if this technique is solely relied upon.

Evaluating Variations in Indocyanine Green Administration and Its Impact on Nodal Yield in Oesophagogastric Cancer Surgery

BACKGROUND

Indocyanine green (ICG), a near-infrared fluorescent dye, has the potential to improve oncological outcomes by increasing lymph node yield in oesophagogastric (OG) cancer. There is no consensus regarding the dose, timing, and method of injection. This study was designed to evaluate the variation in ICG administration and its potential impact on nodal yield in OG cancer surgery for the purpose of translation in Western patients.

METHODS

A systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The primary outcome of this review was nodal yield, and the secondary outcome was the diagnostic accuracy of ICG in detecting metastatic lymph nodes. A meta-analysis of diagnostic accuracy data was performed by using a random-effects model.

RESULTS

A total of 38 studies (12,138 patients) were included in the analysis. Nodal yield was significantly increased in the ICG groups by 7.6 nodes (95% confidence interval [CI] 5.9-9.4; P = 0.0001) compared with control. Trends towards greater nodal yield were observed when ICG was administered at doses less than 2.75 mg, on the day before surgery, and via subserosal injection, although these did not reach statistical significance. Of the 17 studies with diagnostic accuracy data, the pooled sensitivity and specificity of ICG were 0.81 (95% CI 0.67-0.90) and 0.41 (95% CI 0.29-0.53), I2 90.5%.

CONCLUSIONS

Indocyanine green-assisted lymphadenectomy significantly increased lymph node yield, which may translate into improved survival in patients with OG cancer. The ICG dose, timing, and method of injection warrant standardisation to maximise its potential benefits in Western patients.

Comparative study of ICG and non-ICG-guided laparoscopic gastrectomy for gastric cancer: a propensity score-matched analysis at a single center

ABSTRACT

Objectives

To investigate the effectiveness of indocyanine green (ICG) lymphography in improving lymph nodes (LNs) harvesting during laparoscopic radical distal gastrectomy for gastric cancer.

Design

Non-randomized trial, prospective study compared ICG and non-ICG group using 1:1 propensity score matching (PSM) method.

Setting

Preoperative clinical characteristics, operative outcomes, and follow-up results.

Participants

242 patients who underwent laparoscopic distal gastrectomy with D2 lymphadenectomy for gastric cancer between 2019 and 2023. After exclusion and PSM, 160 patients (Pts) were included, paired in two groups: ICG (80 Pts) and non-ICG (80 Pts).

Interventions

Patients in the ICG group underwent ICG injection submucosal via endoscopy 1 day before surgery.

Main outcome measures

Comparison of the number of retrieved LNs and complications between the ICG and non-ICG group.

Results

There were no significant differences in age, sex, height, tumor size, pathological Tumor-stage, histological differentiation, and complications between the two groups. There was a shorter operative time in the ICG group compared with the non-ICG group (median: 118 mins (IQR, 105-135) vs 146 mins (IQR, 120-180), respectively). Regarding the effectiveness of LN dissection: the ICG group had a higher median of retrieved LNs than the non-ICG group (36 LNs (IQR, 29-46) vs 27 LNs (IQR, 21-31); p<0.001). The mean number of metastatic LNs in the ICG group was significantly higher than in the non-ICG group, with 2.6±5.4 LNs compared with 0.9±3.1 LNs, respectively (p=0.018). The proportion of patients with more than 25 and 30 retrieved LNs was higher in the ICG group compared with the non-ICG group, with rates of 86% and 71% versus 64% and 31%, respectively (p<0.001).

Conclusions

Using ICG fluorescence-guided LNs dissection has increased both the number of total LNs and metastatic LNs dissection without increasing complications in laparoscopic distal gastrectomy for gastric cancer.

Case series on the use of the indocyanine green fluorescence real-time imaging technique for lymph node sorting in patients undergoing radical esophagectomy

Background

There is a clear correlation between accurate postoperative lymph node staging and the survival prognosis of patients. This study aimed to explore the application and value of indocyanine green (ICG) fluorescence real-time imaging technology in lymph node sorting during radical esophagectomy for esophageal cancer.

Methods

From August 2022 to June 2023, the specimens of 66 patients who underwent esophageal cancer resection with lymph node dissection were examined. Among them, 12 cases of ex vivo esophageal specimens underwent secondary lymph node sorting using ICG fluorescence real-time imaging technology after conventional lymph node sorting, while the remaining 54 cases underwent conventional lymph node sorting.

Results

A total of 329 lymph nodes were detected in the 12 patients with an average of 29.75±9.19 nodes per patient. Lymph node metastasis was detected in five patients, of whom, three were diagnosed as N1 (N refers to regional lymph nodes, N1: involves 1 to 2 regional lymph node metastases), and two were diagnosed as N2 (N refers to regional lymph nodes, N2: involves 3-6 regional lymph node metastases). Following the ICG injection of 12 patient specimens, lymph nodes were re-detected in 6 patients of them (above we stated 12 patients), yielding a detection rate of 50%. In total, 17 lymph nodes were detected. There was a statistically significant difference in the total number of lymph nodes detected before and after the injection of ICG (P=0.02). Among the other 54 patients, an average of 34.06±15.66 lymph nodes were detected. There was no statistically significant difference in the total number of lymph nodes detected between the two groups (P=0.21).

Conclusions

The use of ICG fluorescence real-time imaging technology facilitate lymph node identification in resected specimens and will become a powerful technique for precise staging in esophageal cancer treatment.

Indocyanine green and near-infrared fluorescence-guided surgery for gastric cancer: a narrative review

In recent years, indocyanine green (ICG) and near-infrared (NIR) fluorescence-guided surgery has become a versatile and well-researched tool for gastric cancer treatment. Our narrative review aims to explore the applications, benefits, and challenges that are associated with this technique. Initially used to detect sentinel lymph nodes in early gastric cancer, its scope has broadened to include several clinical applications. Its most notable advantages are the ability to guide standard lymphadenectomy, intraoperatively localize tumors and define tumor margins. Despite these advantages, there are still ongoing discussions regarding its accuracy, lack of standardized administration, and oncologic safety in sentinel node navigation surgery. The limited tumor specificity of ICG has been especially put into question, hindering its ability to accurately differentiate between malignant and healthy tissue. With ongoing innovations and its integration into newer endoscopic and robotic systems, ICG-NIR fluorescence imaging shows promise in becoming a standard tool in the surgical treatment of gastric cancer.

Developments in the Use of Indocyanine Green (ICG) Fluorescence in Colorectal Surgery

Indocyanine Green (ICG) has significantly advanced minimally invasive surgery. It is widely recognized for its ability to visualize blood vessel patency in real-time across various surgical specialties. While its primary use in colorectal surgery is to evaluate anastomoses for leaks, numerous other applications have been documented in the literature. In this review, we aim to explore both established and emerging applications of ICG fluorescence in colorectal surgery, with the goal of improving patient outcomes. This includes preoperative tumor marking and the detection of metastatic disease. Some applications, such as lymphatic mapping, require further research to determine their impact on clinical practices. Conversely, others, like the intraoperative localizations of ureters, necessitate additional procedures and are not yet widely accepted by the surgical community. However, the development of alternative compounds could offer better solutions. Future research should focus on areas like quantitative ICG and protocol standardization in prospective multicenter studies.

Current applications of indocyanine green (ICG) in abdominal, gynecologic and urologic surgery: a meta-review and quality analysis with use of the AMSTAR 2 instrument

BACKGROUND

Indocyanine green (ICG) is an injectable fluorochrome that has recently gained popularity as a means of assisting intraoperative visualization during laparoscopic and robotic surgery. Many systematic reviews and meta-analyses have been published. We conducted a meta-review to synthesize the findings of these studies.

METHODS

PubMed and Embase were searched to identify systematic reviews and meta-analyses coping with the uses of ICG in abdominal operations, including Metabolic Bariatric Surgery, Cholecystectomy, Colorectal, Esophageal, Gastric, Hepato-Pancreato-Biliary, Obstetrics and Gynecology (OG), Pediatric Surgery, Surgical Oncology, Urology, (abdominal) Vascular Surgery, Adrenal and Splenic Surgery, and Interdisciplinary tasks, until September 2023. We submitted the retrieved meta-analyses to qualitative analysis based on the AMSTAR 2 instrument.

RESULTS

We identified 116 studies, 41 systematic reviews (SRs) and 75 meta-analyses (MAs), spanning 2013-2023. The most thoroughly investigated (sub)specialties were Colorectal (6 SRs, 25 MAs), OG (9 SRs, 15 MAs), and HPB (4 SRs, 12 MAs). Interestingly, there was high heterogeneity regarding the administered ICG doses, routes, and timing. The use of ICG offered a clear benefit regarding anastomotic leak prevention, particularly after colorectal and esophageal surgery. There was no clear benefit regarding sentinel node detection after OG. According to the AMSTAR 2 tool, most meta-analyses ranked as "critically low" (34.7%) or "low" (58.7%) quality. There were only five meta-analyses (6.7%) that qualified as "moderate" quality, whereas there were no "high" quality reviews.

CONCLUSIONS

Regardless of the abundance of pertinent literature and reviews, surgeons should be cautious when interpreting their results on ICG use in abdominal surgery. Future reviews should focus on ensuring methodological vigor; establishing clear protocols of ICG dose, route of administration, and timing; and improving reporting quality. Other sources of data (e.g., registries) and novel methods of data analysis (e.g., machine learning) might also contribute to an enhanced role of ICG as a decision-making tool in surgery.

Impact of tumor stage and neoadjuvant chemotherapy in fluorescence-guided lymphadenectomy during laparoscopic gastrectomy for gastric cancer: A propensity score-matched study in a western center

BACKGROUND

The use of indocyanine green fluorescence has been shown to be a safe and effective method for improving lymph node retrieval in patients with gastric cancer. However, previous studies have focused on early-stage tumors and/or the Asian population and excluded patients who received neoadjuvant treatment.

METHODS

In this study, 142 patients with gastric adenocarcinoma underwent laparoscopic gastrectomy at a Spanish hospital between January 2017 and December 2022. Of these, 42 patients received preoperative indocyanine green injection to guide lymphadenectomy. Their outcomes were compared to a retrospective cohort of 42 patients after 1:1 propensity score matching.

RESULTS

The feasibility of indocyanine green lymphatic mapping was 95.5%. No complications associated with indocyanine green injection were observed. The indocyanine green group had a significantly higher number of retrieved lymph nodes than the non-indocyanine green group (32.67 vs 25.14; P = .013). This statistically significant difference was maintained across subgroups of neoadjuvant treatment, non-obese patients, pT0 to 2 stage, and pN0 stage. In 47.6% of patients from the indocyanine green group, lymphadenectomy was extended outside the standard D2 dissection area based on indocyanine green uptake, but none of the retrieved lymph nodes were metastatic. There were no differences in postoperative complications and length of hospital stay between the 2 groups.

CONCLUSION

Indocyanine green-guided lymphadenectomy is safe and feasible and increases the number of retrieved lymph nodes compared to conventional lymphatic dissection, as well as in patients receiving neoadjuvant chemotherapy. The use of indocyanine green should be routine if available for guiding lymph node dissection in gastric cancer, regardless of tumor stage or previous neoadjuvant treatment. However, further studies are needed to determine the impact of this technique on disease-free and overall survival.

[Fluorescence navigation and angiography with indocyanine green in stomach cancer surgery]

OBJECTIVE

To evaluate the effectiveness of intraoperative angiography and fluorescence navigation with indocyanine green in reducing the risks of intra- and postoperative complications, as well as resection quality in patients with gastric cancer.

MATERIAL AND METHODS

The main group consisted of patients who underwent intraoperative angiography and fluorescence navigation with indocyanine green (n=43). The control group included patients without these procedures (n=154). Both groups did not differ in gender (p=0.937) and age (p=0.437). The lower third of the stomach was the most common tumor location in the main group (62.7% of cases), the middle and lower thirds of the stomach - in the control group (37% and 38.9% of patients, respectively). There was no between-group difference in «cT» grading (p>0.05). However, there were more «cN+» patients in the main group (14 (32.6%) versus 28 (18.4%) ones of «N0» category, p=0.042). Therefore, 41.9% and 13.6% of patients underwent neoadjuvant chemotherapy in both groups, respectively (<0.001).

RESULTS

Intraoperative angiography and fluorescence navigation with indocyanine green does not increase mortality (p=0.631), incidence of major (CD 3-5) (p=0.436) and minor (CD 1-2) postoperative complications (p=0.177), surgery time (p=0.288), mean intraoperative blood loss (p=0.144) and length of hospital-stay (p=0.631). Fluorescence navigation with indocyanine green does not affect the number of detected «positive» resection margins (R1) (p=0.883) but significantly increases the number of excised lymph nodes (p<0.001).

CONCLUSION

Intraoperative angiography and fluorescence navigation with indocyanine green are safe for intraoperative visualization of tumor and lymph nodes, as well as assessment of arterial blood supply. This technique is effective in traditional and minimally invasive surgeries for gastric cancer. Fluorescence navigation with indocyanine green significantly increases the number of excised lymph nodes.

Fluorescence use in minimally invasive metabolic and bariatric surgery - a systematic review of the literature

PURPOSE

This review aims to explore and summarise current knowledge of indocyanine green (ICG) fluorescence application in metabolic and bariatric surgery (MBS) and assess its potential in improving patient safety.

METHODS

The review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Evidence from PubMed, ScienceDirect and Ovid MEDLINE databases was independently screened in October 2022. The primary information and outcomes were the type of fluorescence application with potential patient benefit and the complication rate. The secondary outcomes consisted of the kind of dye, the application protocol, and the equipment used.

RESULTS

Thirteen publications were included, with six prospective observational studies, five case reports and two retrospective cohort studies and involved a total of 424 patients. The publications were categorized into four groups based on the method of fluorescence application. Sixty-six percent of the cases used fluorescence for LSG, 32.3% used it for RYGB, 1.2% for revisional surgery, 0.2% during removal of an adjustable gastric band, and 0.2% for LSG combined with Rossetti fundoplication. ICG was used on its own in the majority of studies, although in one case, it was used in combination with methylene blue. ICG administration protocols varied significantly. Complications occurred in three patients (0.71%): leaks were diagnosed in two cases, and one patient required a blood transfusion.

CONCLUSION

The most popular type of use is intraoperative assessment of the blood supply. ICG application may reduce the risk of complications, with potential benefits in detecting ischemia and leaks, searching for bleeding in areas inaccessible to endoscopy, and non-invasive hepatopathy evaluation.

Preclinical evaluation of sentinel node localization in the stomach via mannose-labelled magnetic nanoparticles and indocyanine green

BACKGROUND

Gastrectomy with extended (D2) lymphadenectomy is considered standard of care for gastric cancer to provide the best possible outcomes and pathologic staging. However, D2 gastrectomy is a technically demanding operation and reported to be associated with increased complications and mortality. Application of sentinel lymph node (SLN) concept in gastric cancer has the potential to reduce patient morbidity; however, SLN techniques are not established for gastrectomy, in part due to lack of practical tracers. An effective and convenient tracer with enhanced SLN accumulation is critically needed.

METHODS

Mannose-labelled magnetic tracer 'FerroTrace' and fluorescent dye indocyanine green (ICG) were injected laparoscopically into the stomach submucosa of 8 healthy swine under general anaesthesia. Intraoperative fluorescence imaging was used to highlight draining lymphatic pathways containing ICG, while preoperative T2-weighted MRI and ex vivo magnetometer probe measurements were used to identify nodes containing FerroTrace. Lymphadenectomy was performed either robotically (n = 2) or via laparotomy (n = 6).

RESULTS

Mixing ICG and FerroTrace ensured concurrence of fluorescent and magnetic signals in SLNs. An initial trial with robotic dissection removed all magnetic LNs (n = 4). In the subsequent laparotomy study that targeted all ICG-LNs based on intraoperative fluorescence imaging, dissection removed an average of 4.7 ± 1.2 fluorescent, and 2.0 ± 1.3 magnetic LNs per animal. Both MRI and magnetometer detected 100% of SLNs (n = 7). FerroTrace demonstrated high specificity to SLNs, which contained 76 ± 30% of total lymphotropic iron, and 88 ± 20 % of the overall magnetometer signal.

CONCLUSIONS

Through utilisation of this dual tracer approach, SLNs were identified via preoperative MRI, visualised intraoperatively with fluorescence imaging, and confirmed with a magnetometer. This combination pairs the sensitivity of ICG with SLN-specific FerroTrace and can be used for reliable SLN detection in gastric cancer, with potential applications in neoadjuvant therapy.

Assessment of the efficacy and safety of carbon nanoparticles-guided lymph node dissection in gastric cancer surgery: a systematic review and meta-analysis

BACKGROUND

To investigate the efficacy and safety of lymph nodes (LNs) dissection guided by carbon nanoparticles (CNs) in gastric cancer (GC) surgery.

MATERIALS AND METHODS

We searched electronic databases such as PubMed, Web of Science, Embase, Cochrane Library, and Scopus for relevant articles up to September 2022 and collected all studies comparing the CNs group with blank controls group on the efficacy and safety of LN dissection in gastrectomy. A pooled analysis of the collected data was performed, including the number of retrieved LNs, the staining rate of LNs, the number of metastatic LNs dissection, various intraoperative outcomes, and postoperative complications.

RESULTS

A total of 9 studies including 1770 participants (502 in the CNs group and 1268 in the control group) were included. As compared to the blank control group, the CNs group detected 10.46 more LNs in each patient (WMD = 10.46, 95% CI: 6.63 ~ 14.28, p < 0.00001, I² = 91%), and also significantly more metastatic LNs (WMD = 2.63, 95% CI: 1.43 ~ 3.83, p < 0.0001, I² = 41%). However, there was no significant difference in the rate of metastatic LNs between the CNs and control groups (OR = 1.37, 95% CI: 0.94 ~ 2.00, P = 0.1, I² = 89%). In addition, there was no increase in operative time, intraoperative blood loss, and postoperative complications associated with CNs-guided gastrectomy.

CONCLUSION

CNs-guided gastrectomy is safe and effective, and can increase the efficiency of LN dissection without increasing the risk of surgery.

Advances in surgical techniques for gastric cancer: Indocyanine green and near-infrared fluorescence imaging. Is it ready for prime time?

Surgery is still the primary curative treatment for gastric cancer, which includes resection of the tumor with adequate margins and extended lymphadenectomy. In order to improve the operative results and the quality of life of patients, several endeavors have been made toward precision medicine through image-guided surgery, allowing access to real-time intraoperative anatomy and accurate tumor staging. The goal of the surgeon is to achieve a more precise, individualized, and less invasive surgery without compromising oncological efficiency and safety. In this perspective, we have demonstrated the role of indocyanine green (ICG) and near-infrared (NIR) fluorescence imaging method in gastric cancer surgery. This technique may be used to improve localization of the tumor, detection of sentinel lymph nodes (SLN), real-time lymphatic mapping, and blood flow assessment (anastomosis perfusion).

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.