Comparison of submucosal and subserosal approaches toward optimized indocyanine green tracer-guided laparoscopic lymphadenectomy for patients with gastric cancer (FUGES-019): a randomized controlled trial

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.

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.

Safety and efficacy of indocyanine green-guided laparoscopic lymphadenectomy for locally advanced gastric cancer: The CLASS-11 clinical trials

We report the short-term results of indocyanine green (ICG)-guided laparoscopic lymphadenectomy for gastric cancer (GC). The primary outcome is 3-year disease-free survival. In this analysis, we present short-term secondary outcomes focused on the number of lymph nodes (LNs) retrieved and the diagnostic value of fluorescent status for metastatic LNs, excluding long-term outcomes. A total of 1,006 patients are included in the per-protocol analysis. The mean number of LNs retrieved in the ICG group is significantly higher than that in the non-ICG group. The negative predictive value is 93.9% for nonfluorescent stations, and the sensitivity of ICG for detecting all metastatic LN stations is 91.6%. ICG technology is safe and feasible for laparoscopic lymphadenectomy in GC and can noticeably increase the number of LNs retrieved. Further follow-up is necessary to warrant whether ICG can improve long-term survival of GC. The Chinese Laparoscopic Gastrointestinal Surgery Study (CLASS)-11 trial has been registered at ClinicalTrials.gov as NCT04593615.

Efficacy and safety of subserosal versus submucosal carbon nanoparticle-guided laparoscopic radical gastrectomy (DANCE-04): A randomized clinical trial

BACKGROUND

To compare the efficacy in lymph node dissection, perioperative safety, and cost of subserosal and submucosal administration of carbon nanoparticles in laparoscopic radical gastrectomy for gastric cancer.

METHODS

This was a randomized clinical trial. Patients with potentially resectable gastric cancer (cT1-4a, cNany, cM0) were randomized into subserosal or submucosal groups. Laparoscopic D2 lymphadenectomy was performed for each patient.

RESULTS

Between September 2023 and August 2024, 49 patients were enrolled in the subserosal group and 50 patients were enrolled in the submucosal group. The number of retrieved lymph nodes in the subserosal group was significantly greater than that in the submucosal group (36.6 ± 1.4 vs 32.2 ± 1.4, P = .02). The number of retrieved metastatic lymph nodes in the subserosal group was also significantly greater than that in the submucosal group (3.1 ± 0.6 vs 1.5 ± 0.5, P = .04). The duration of surgery in the subserosal group was shorter than that in the submucosal group (150.9 ± 3.0 minutes vs 194.7 ± 6.2 minutes, P < .001). The tracing-related cost in the subserosal group was lower than that in the submucosal group (1,824.8 ± 110.9 vs 2,395.5 ± 112.5 [in Chinese currency], P < .001), whereas the tracing-excluded cost was similar between groups. Diagnostic values, including sensitivity, specificity, positive predictive value, and negative predictive value for metastatic stations or lymph nodes, of the subserosal approach were superior to those of the submucosal approach.

CONCLUSION

Subserosal is superior to submucosal administration of carbon nanoparticles in lymph node dissection with comparable perioperative safety and decreased tracing-related cost in laparoscopic radical gastrectomy for gastric cancer.

TRIAL REGISTRATION

ISRCTN11247387 (https://doi.org/10.1186/ISRCTN11247387).

Prognostic Impact of Fluorescent Lymphography on Gastric Cancer After Neoadjuvant Chemotherapy

Importance

Indocyanine green (ICG)-guided lymphadenectomy has been increasingly used to treat gastric cancer. However, its oncologic impact remains unclear.

Objective

To investigate the effect of ICG tracing on long-term outcomes in patients diagnosed with locally advanced gastric cancer undergoing neoadjuvant chemotherapy (NAC) followed by laparoscopic radical gastrectomy.

Design, Settings, and Participants

This retrospective cohort study included patients diagnosed with cT2-4N0/+M0 gastric adenocarcinoma who underwent NAC and laparoscopic radical gastrectomy at 3 teaching hospitals in China between January 2015 and June 2021, with follow-up data examined until June 2024. Overlap weighting (OW) was used to compare outcomes between the ICG and non-ICG groups. Results were tested for robustness using propensity score matching (PSM) and instrumental variable analysis.

Exposure

ICG-guided lymphadenectomy during laparoscopic gastrectomy.

Main Outcomes and Measures

The primary end points were 3-year survival outcomes, including overall survival (OS) and recurrence-free survival (RFS).

Results

Data from 459 patients (338 men [73.6%] and 121 women [26.4%]; mean [SD] age, 60.8 [9.9] years), of whom 119 underwent ICG-guided lymphadenectomy, were included. After OW adjustment, the ICG group exhibited a higher number of lymph nodes harvested (47.4 vs 38.3; P < .001) and better 3-year OS (78.6% vs 66.6%; P = .04) and RFS (74.0% vs 57.0%; P = .03) compared with the non-ICG group. Multivariable Cox regression analysis revealed that ICG tracing was an independent prognostic factor for both OS (hazard ratio, 0.59; 95% CI, 0.39-0.90; P = .02) and RFS (hazard ratio, 0.59; 95% CI, 0.40-0.87; P = .01), with the results remaining significant in both doubly robust and instrumental variable-adjusted models. Furthermore, in the OW-adjusted population, the OS benefit of ICG tracing was more pronounced in subgroups with ypN2/3 gastric adenocarcinoma (70.3% vs 36.2%; P = .01) and those achieving major pathological response (97.7% vs 77.6%; P = .04) (both P for interaction = .04). Similar results were obtained after adjusting for PSM.

Conclusion and Relevance

In this study, ICG tracing was associated with enhanced lymphadenectomy and improved survival outcomes in patients with locally advanced gastric cancer after NAC. A prospective randomized clinical trial is needed to verify these findings.

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.

[Evidence for the extent and oncological benefit of lymphadenectomy for esophageal cancer]

The prognosis for esophageal cancer is determined in particular by the depth of infiltration (T stage) and lymph node metastasis (N status). In patients with locally advanced tumors, surgical resection is the current standard. The extent of the lymphadenectomy depends on the localization of the tumor, analogous to the choice of surgical technique. For adequate tumor staging and achievement of pN0 status, seven lymph nodes without tumor metastases are necessary by definition but the current guidelines recommend 20 lymph nodes as a benchmark in an expert consensus. Despite the importance of the lymph node status for the prognosis of the patient and the already standardized use of targeted imaging of sentinel lymph nodes in other oncological disciplines, there is neither a validated method nor sufficient evidence for the benefit of lymph node mapping in esophageal cancer. The discussion about the prognostic advantage of lymphadenectomy is particularly interesting in T1 early stage cancer. Due to the technical advances of interventional endoscopy in recent years, organ preservation using endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR) has not only become possible but also safe to carry out and thus established as the standard with better functional results; however, if one or more risk factors are present, endoscopic ablation is no longer defined as curative and should be supplemented by further treatment, usually non-organ-preserving resection. The step from organ-preserving interventional treatment with a low complication rate to a surgical procedure with significant mortality and morbidity as well as functional limitations seems immense and requires optimization, especially in view of the technical developments of surgery in recent years. This can either aim to identify the risk of lymph node metastases more precisely or to minimize the morbidity/mortality and functional limitations of additive treatment procedures. Approaches to this are currently the subject of research and have already been safely applied in individual pilot projects.

Comparison of a submucosal and subserosal approach in ICG-guided laparoscopic lymphadenectomy in gastric cancer patients: long-term outcomes of a phase 3 randomized clinical trial

BACKGROUND

Previous studies have demonstrated similar short-term efficacy between subserosal (SSA) and submucosal (SMA) approaches for ICG injection in gastric cancer (GC). This study aims to compare the long-term oncological outcomes of these two injection methods for lymph node (LN) tracing in ICG-guided laparoscopic gastrectomy.

MATERIALS AND METHODS

This study was a phase 3, open-label, randomized clinical trial (FUGES-019). A total of 266 patients with resectable gastric adenocarcinoma (cT1-4a, N0/ +, M0) were enrolled. We report predefined long-term secondary outcomes, including three-year actual overall survival (OS), three-year actual disease-free survival (DFS), and recurrence patterns.

RESULTS

Of the 266 participants, 259 patients were included in the per-protocol analysis: 129 in the SSA group and 130 in the SMA group. The actual OS in the SSA group (87.6%) was comparable to that in the SMA group (90.8%, P = 0.41), as were the 3-year actual DFS rates (SSA: 82.9% vs. SMA: 88.5%, log-rank P = 0.19). Per-protocol analysis confirmed the equivalence of the SSA compared with the SMA. The most common type of recurrence was multiple site metastasis (11 of 259[4.24%]), with no differences in recurrence types across cancer stages. Further stratified analysis based on pT, pN staging, tumor size, and BMI showed no significant differences between the two groups.

CONCLUSION

The 3-year outcomes of the FUGES-019 trial confirm the equivalence of SSA and SMA in ICG-guided laparoscopic lymphadenectomy for GC, supporting the previous short-term findings. The subserosal approach can be recommended for ICG administration based on clinical considerations.

Effect of carbon nanoparticle suspension injection versus indocyanine green tracer in guiding lymph node dissection during radical gastrectomy (FUTURE-01): a randomized clinical trial

BACKGROUND

Carbon nanoparticle suspension injection (CNSI) and indocyanine green (ICG) have both been applied intraoperatively to facilitate lymphatic mapping and postoperatively to sort lymph nodes (LNs) in gastric cancer patients. However, no study has compared the two tracers in gastric cancer patients.

MATERIALS AND METHODS

This prospective randomized controlled trial was conducted from January 2022 to March 2023. Patients with potentially resectable gastric cancer (cT1-4a N0/+ M0) were randomized to the CNSI or ICG group.

RESULTS

This study enrolled 96 patients. Ninety patients were in the modified intention-to-treat population, including 46 patients [32 males and 14 females; mean (SD) age, 57.4 (9.4) years] in the CNSI group and 44 patients [31 males and 13 females; mean (SD) age, 60.8 (8.8) years] in the ICG group. The mean (SD) number of retrieved LNs was 69.8 (21.9) and 53.6 (17.2) in the CNSI and ICG groups, respectively ( P <0.001). The mean (SD) number of retrieved micro-LNs was 19.9 (13.3) and 11.6 (9.9) in the CNSI and ICG groups, respectively ( P =0.001). The mean (SD) number of metastatic LNs was 8.1 (11.9) and 5.2 (9.2) in the CNSI and ICG groups, respectively ( P =0.19).

CONCLUSIONS

Compared with ICG, CNSI can increase the number of LNs detected, especially micro-LNs. Both tracers have high diagnostic value for detecting metastatic LNs. CNSI-guided lymphography may be a superior method for improving the accuracy of LN dissection.

Current clinical trials on gastric cancer surgery in China

Gastric cancer (GC) is the leading diagnosed malignancy worldwide, especially in China. Radical surgery is the cornerstone of GC treatment. We reviewed previous clinical trials and aimed to provide an update on the factors related to the surgical treatment of GC. The number of registered clinical trials in the field of GC surgery is rapidly increasing. With the development and popularization of endoscopic, laparoscopic, and robotic techniques, GC surgery has gradually entered a new era of precise minimally invasive surgery. Postoperative quality of life has become a major issue in addition to surgical oncological safety. Although great progress has been made in clinical research on GC in China, there are still deficiencies. Many studies enrolled large numbers of patients, but the research data were not of high quality. The characteristics of GC in China include a high incidence, large population, and large proportion of patients with advanced GC, which provides sufficient reason for studying this disease. There is still a need for well-designed, large, randomized clinical trials to improve our knowledge of the surgical treatment of GC.

Fluorescence-guided laparoscopic lymph node biopsy for lymphoma: the FLABILY study

To date, no reports have indicated laparoscopic lymph node biopsies using Indocyanine green (ICG) in cases of lymphoproliferative disease. Preliminary data of patients undergoing fluorescence-guided laparoscopic lymph node biopsy (FGLLB) using ICG was retrospectively analysed from the multicentre registry FLABILY study. Between June 2022 and February 2024, 50 patients underwent FGLLB. The surgical biopsy aimed to re-stage lymphoproliferative disease for 25 patients and to establish a diagnosis in 25 patients. The median duration of the procedure was 65 ± 26.5 min. All the procedures were performed laparoscopically. One surgical conversion occurred due to bleeding. Median length of hospitalization was 1 ± 1.7 days. Two unrelated complications occurred in the immediate postoperative course. ICG was administrated preoperatively by means of an inguinal, perilesional, or intravenous injection according to the anatomical sites of the biopsy. Fluorescence was obtained in 43/50 (86%) of patients. A significant difference was highlighted in the appearance of fluorescence in sub-mesocolic lymph nodes compared to supra-mesocolic and mesenteric lymph nodes (41/49 (83.6%) vs. 13/22 (59%), p = 0,012). In 98% of cases, FGLLB provided the information necessary for the correct diagnosis. Fluorescence with ICG offers a simple and safe method for detecting pathological lymph nodes. FGLLB in suspected intra-abdominal lymphoma can largely benefit from this new opportunity which, to date, has not yet been tested. Further studies with a larger case series are needed to confirm its efficacy.

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.

Survival prognostic analysis of laparoscopic D2 radical resection for locally advanced gastric cancer: A multicenter cohort study

BACKGROUND

With the development of minimally invasive surgical techniques, the use of laparoscopic D2 radical surgery for the treatment of locally advanced gastric cancer (GC) has gradually increased. However, the effect of this procedure on survival and prognosis remains controversial. This study evaluated the survival and prognosis of patients receiving laparoscopic D2 radical resection for the treatment of locally advanced GC to provide more reliable clinical evidence, guide clinical decision-making, optimize treatment strategies, and improve the survival rate and quality of life of patients.

AIM

To investigate the survival prognosis and influencing factors of laparoscopic D2 radical resection for locally advanced GC patients.

METHODS

A retrospective cohort study was performed. Clinicopathological data from 652 patients with locally advanced GC in our hospitals from December 2013 to December 2023 were collected. There were 442 males and 210 females. The mean age was 57 ± 12 years. All patients underwent a laparoscopic D2 radical operation for distal GC. The patients were followed up in the outpatient department and by telephone to determine their tumor recurrence, metastasis, and survival. The follow-up period ended in December 2023. Normally distributed data are expressed as the mean ± SD, and normally distributed data are expressed as M (Q1, Q3) or M (range). Statistical data are expressed as absolute numbers or percentages; the χ 2 test was used for comparisons between groups, and the Mann-Whitney U nonparametric test was used for comparisons of rank data. The life table method was used to calculate the survival rate, the Kaplan-Meier method was used to construct survival curves, the log rank test was used for survival analysis, and the Cox risk regression model was used for univariate and multifactor analysis.

RESULTS

The median overall survival (OS) time for the 652 patients was 81 months, with a 10-year OS rate of 46.1%. Patients with TNM stages II and III had 10-year OS rates of 59.6% and 37.5%, respectively, which were significantly different (P < 0.05). Univariate analysis indicated that factors such as age, maximum tumor diameter, tumor differentiation grade (low to undifferentiated), pathological TNM stage, pathological T stage, pathological N stage (N2, N3), and postoperative chemotherapy significantly influenced the 10-year OS rate for patients with locally advanced GC following laparoscopic D2 radical resection for distal stomach cancer [hazard ratio (HR): 1.45, 1.64, 1.45, 1.64, 1.37, 2.05, 1.30, 1.68, 3.08, and 0.56 with confidence intervals (CIs) of 1.15-1.84, 1.32-2.03, 1.05-1.77, 1.62-2.59, 1.05-1.61, 1.17-2.42, 2.15-4.41, and 0.44-0.70, respectively; P < 0.05]. Multifactor analysis revealed that a tumor diameter greater than 4 cm, low tumor differentiation, and pathological TNM stage III were independent risk factors for the 10-year OS rate in these patients (HR: 1.48, 1.44, 1.81 with a 95%CI: 1.19-1.84). Additionally, postoperative chemotherapy emerged as an independent protective factor for the 10-year OS rate (HR: 0.57, 95%CI: 0.45-0.73; P < 0.05).

CONCLUSION

A maximum tumor diameter exceeding 4 cm, low tumor differentiation, and pathological TNM stage III were identified as independent risk factors for the 10-year OS rate in patients with locally advanced GC following laparoscopic D2 radical resection for distal GC. Conversely, postoperative chemotherapy was found to be an independent protective factor for the 10-year OS rate in these patients.

Fluorescence imaging-guided surgery: current status and future directions

Surgery is one of the most important paradigms for tumor therapy, while fluorescence imaging (FI) offers real-time intraoperative guidance, greatly boosting treatment prognosis. The imaging fidelity heavily relies on not only imaging facilities but also probes for imaging-guided surgery (IGS). So far, a great number of IGS probes with emission in visible (400-700 nm) and near-infrared (NIR 700-1700 nm) windows have been developed for pinpointing disease margins intraoperatively. Herein, the state-of-the-art fluorescent probes for IGS are timely updated, with a special focus on the fluorescent probes under clinical examination. For a better demonstration of the superiority of NIR FI over visible FI, both imaging modalities are critically compared regarding signal-to-background ratio, penetration depth, resolution, tissue autofluorescence, photostability, and biocompatibility. Various types of fluorescence IGS have been summarized to demonstrate its importance in the medical field. Furthermore, the most recent progress of fluorescent probes in NIR-I and NIR-II windows is summarized. Finally, an outlook on multimodal imaging, FI beyond NIR-II, efficient tumor targeting, automated IGS, the use of AI and machine learning for designing fluorescent probes, and the fluorescence-guided da Vinci surgical system is given. We hope this review will stimulate interest among researchers in different areas and expedite the translation of fluorescent probes from bench to bedside.

Assessment of Laparoscopic Indocyanine Green Tracer-guided Lymphadenectomy After Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer: A Randomized Controlled Trial

OBJECTIVE

To assess the effectiveness of indocyanine green (ICG)-guided lymph node (LN) dissection during laparoscopic radical gastrectomy after neoadjuvant chemotherapy (NAC) in patients with locally advanced gastric cancer (LAGC).

BACKGROUND

Studies on ICG imaging use in patients with LAGC on NAC are rare.

METHODS

Patients with gastric adenocarcinoma (clinical T2-4NanyM0) who received NAC were randomly assigned to receive ICG-guided laparoscopic radical gastrectomy or laparoscopic radical gastrectomy alone. Here, we reported the secondary endpoints including the quality of lymphadenectomy (total retrieved LNs and LN noncompliance) and surgical outcomes.

RESULTS

Overall, 240 patients were randomized. Of whom, 236 patients were included in the primary analysis (118 in the ICG group and 118 in the non-ICG group). In the ICG group, the mean number of LNs retrieved was significantly higher than in the non-ICG group within the D2 dissection (48.2 vs 38.3, P < 0.001). The ICG fluorescence guidance significantly decreased the LN noncompliance rates (33.9% vs 55.1%, P = 0.001). In 165 patients without baseline measurable LNs, ICG significantly increased the number of retrieved LNs and decreased the LN noncompliance rate ( P < 0.05). For 71 patients with baseline measurable LNs, the quality of lymphadenectomy significantly improved in those who had a complete response ( P < 0.05) but not in those who did not ( P > 0.05). Surgical outcomes were comparable between the groups ( P > 0.05).

CONCLUSIONS

ICG can effectively improve the quality of lymphadenectomy in patients with LAGC who underwent laparoscopic radical gastrectomy after NAC.

Factors Affecting the Efficiency of Near-Infrared Indocyanine Green (NIR/ICG) in Lymphatic Mapping for Colorectal Cancer: A Systematic Review

As laparoscopy gained global popularity in oncologic surgery, the challenge of detecting lymph nodes spurred researchers to explore innovative techniques and approach the situation from a fresh perspective. While many proposed methods have faded into obscurity, the utilization of indocyanine green (ICG) in the surgical treatment of oncologic patients has continued to advance. The immense potential of this dye is widely acknowledged, yet its full extent and limitations in lymphatic mapping for colorectal cancer remain to be precisely determined. This article aims to assess the magnitude of its potential and explore the constraints based on insights from clinical studies published by pioneering researchers. A systematic review of the existing literature, comprising articles in English, was conducted using the Scopus, PubMed, and Springer Link databases. The search employed keywords such as "colorectal cancer" AND/OR "indocyanine green," "fluorescence" AND/OR "lymphatic mapping" AND/OR "lymph nodes." Initially identifying 129 articles, the application of selection criteria narrowed down the pool to 10 articles, which served as the primary sources of data for our review. Despite the absence of a standardized protocol for the application of ICG in colorectal cancer, particularly in the context of lymphatic mapping, the detection rates have exhibited considerable variation across studies. Nevertheless, all authors unanimously regarded this technique as beneficial and promising. Additionally, it is advocated as an adjunctive tool to enhance the accuracy of cancer staging. Near-infrared (NIR)-enhanced surgery holds the promise of transforming the landscape of oncologic surgery, emerging as a valuable tool for surgeons. However, the absence of a standardized technique and the subjective nature of result assessment impose limitations on the potential of this method. Consequently, it can be inferred that the establishment of a universally accepted protocol, encompassing parameters such as dose, concentration, technique, and site of administration of ICG, along with the optimal time needed for fluorescence visualization, would enhance the outcomes. Emphasizing the accurate selection of patients is crucial to prevent the occurrence of false-negative results.

[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.

Lymph node mapping with ICG near-infrared fluorescence imaging: technique and results

PURPOSE

Lymphadenectomy represents a fundamental step during gastrointestinal cancer resection, as the removal of an adequate number of lymph nodes is crucial to define the stage of the disease and prognosis. Lymphadenectomy during gastric and colorectal resection and adrenalectomy for cancer are technically demanding and can be associated with risk of bleeding. To date, lymphadenectomy is often performed without any visual aid. Indocyanine green fluorescence for lymph node mapping can provide better intraoperative visualization. The purpose of this review is to report the current evidence on this topic.

MATERIALS AND METHODS

A systematic research of the electronic databases Medline, Embase and Google Scholar was conducted from the inception to December 2022.

RESULTS

This review summarizes the current evidence of techniques and results of fluorescence guided lymphatic mapping during gastrointestinal and adrenal surgery.

CONCLUSION

According to this review, ICG guided lymphadenectomy for gastrointestinal tumours and adrenocortical carcinoma is feasible and safe. In gastrointestinal tumours it allows higher number of harvested lymph nodes.

Subserosal Indocyanine Green Plus Submucosal Carbon Nanoparticle Navigated Laparoscopic Gastrectomy (DANCE-01): a Cohort Study

BACKGROUND

Indocyanine green (ICG) and carbon nanoparticle (CN) have been widely used for radical gastrectomy. However, synchronous application of ICG and CN in gastrectomy has not been tried yet. For the first time, we herein reported a novel strategy using dual tracers in laparoscopic radical gastrectomy.

METHODS

This is a single-center, single-armed, prospective study. For each qualified patient, submucosal CN was injected the day before surgery, and subserosal ICG was injected immediately before surgery. Standard D2 laparoscopic gastrectomy and lymph node examination were subsequently performed. Demographics, lymph nodes (LNs) and postoperative outcome were collected for analysis. To analyze the safety and efficacy of this novel strategy, two contemporary historic control groups using single tracer were established.

RESULTS

A total of 60 patients underwent dual tracer laparoscopic gastrectomy and were divided into distal (n = 41) and total (n = 19) groups. An average of 53.3 and 62.2 LNs was harvested from two groups, respectively. The average operation duration was 213.3 and 250.0 min, and intra-operative blood loss was 100.2 ml and 94.7 ml. None received combined organ resection. Margin negativity and R0 resection were achieved in all patients. Three (7.3%) complications occurred in distal group. None required second operation or deceased. Postoperative hospitalization was 9.7 and 9.6 days, respectively. Compared to single tracer, more LNs (p < 0.01), shorter operation time (p < 0.01), less blood lost (p < 0.01) and accelerated postoperative recovery (p < 0.01) were observed in dual tracer group.

CONCLUSIONS

We propose a novel, feasible and safe tracing strategy for laparoscopic gastrectomy.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2100051309).

Application of near-infrared fluorescence imaging in theranostics of gastrointestinal tumors

Gastrointestinal cancers have become an important cause of cancer-related death in humans. Improving the early diagnosis rate of gastrointestinal tumors and improving the effect of surgical treatment can significantly improve the survival rate of patients. The conventional diagnostic method is high-definition white-light endoscopy, which often leads to missed diagnosis. For surgical treatment, intraoperative tumor localization and post-operative anastomotic state evaluation play important roles in the effect of surgical treatment. As a new imaging method, near-infrared fluorescence imaging (NIRFI) has its unique advantages in the diagnosis and auxiliary surgical treatment of gastrointestinal tumors due to its high sensitivity and the ability to image deep tissues. In this review, we focus on the latest advances of NIRFI technology applied in early diagnosis of gastrointestinal tumors, identification of tumor margins, identification of lymph nodes, and assessment of anastomotic leakage. In addition, we summarize the advances of NIRFI systems such as macro imaging and micro imaging systems, and also clearly describe the application process of NIRFI from system to clinical application, and look into the prospect of NIRFI applied in the theranostics of gastrointestinal tumors.

New clinical application of indocyanine green in fluorescence-guided laparoscopic lymph-node biopsy in case of lymphoma. Preliminary results on a case series

BACKGROUND

Indocyanine Green (ICG) fluorescence-guided surgery is widely used for intraoperative visualization of lymphatic structures. To date, there are no reports indicating this dye being used in lymph node biopsies for suspected or relapsed lymphoma.

METHODS

Between October 2021 and June 2022, 12 patients underwent a fluorescence-guided laparoscopic lymph node biopsy (FGLLB) using ICG. The following was retrospectively evaluated: the dosage of ICG, the injection site, the number of patients where fluorescence was obtained after ICG administration, and additionally, the parameters indicating the outcome of the surgical procedure.

RESULTS

The median duration of the surgery was 90 min. A laparotomy conversion was required in one case due to bleeding. Fluorescence was obtained in 10/12 (83.3%) patients by means of subcutaneous/perilesional injection in six of the patients, and intravenously in the other four. Hospitalization had a mean duration of three days. There were no major postoperative complications. FGLLB was used in seven patients to follow lymphoproliferative disease progression, and in five patients to establish a diagnosis. In all cases, FGLLB provided the information necessary for the correct diagnosis.

CONCLUSIONS

Fluorescence with ICG offers a simple and safe method for detecting pathological lymph nodes. FGLLB in suspected intra-abdominal lymphoma can largely benefit from this new opportunity which has not yet been tested to date. Further studies with large case series are needed to confirm its efficacy.

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.

Endoscopic fluorescent lymphography for gastric cancer

Lymphography by radioisotope or dye is a well-known technique for visualizing the lymphatic drainage pattern in a neoplastic lesion and it is in use in gastric cancer. Indocyanine green (ICG) more recently has been validated in fluorescent lymphography studies and is under evaluation as a novel tracer agent in gastric cancer. The amount and dilution of ICG injected as well as the site and the time of the injection are not standardized. In our unit, endoscopic submucosal injections of ICG are made as 0.5 mg in 0.5 mL at four peritumoral sites the day before surgery (for a total of 2.0 mg in 2.0 mL). Detection instruments for ICG fluorescence are evolving. Near-infrared systems integrated into laparoscopic or robotic instruments (near-infrared fluorescence imaging) have shown the most promising results. ICG fluorescence recognizes the node that receives lymphatic flow directly from a primary tumor. This is defined as the sentinel lymph node, and it has a high predictive negative value at the cT1 stage, able to reduce the extent of gastrectomy and lymph node dissection. ICG also enhances the number of lymph nodes detected during extended lymphadenectomy for advanced gastric cancer. Nevertheless, the practical effects of ICG use in a single patient are not yet clear. Standardization of the technique and further studies are needed before fluorescent lymphography can be used extensively worldwide. Until then, current guidelines recommend an extensive lymphadenectomy as the standard approach for gastric cancer with suspected metastasis.

Global scientific trends in laparoscopy and gastric cancer in the 21st century: A bibliometric and visual mapping analysis

Aims

To use visual mapping and bibliometrics to analyze and summarize the valuable information on laparoscopic surgery for gastric cancer (GC) obtained in the last 20 years, so as to determine the research hotspots and trends in this field.

Methods

We screened all literature on laparoscopic surgery for GC in the Web of Science published from 2000 to 2022 and analyzed the research hotspots and trends in this field using VOSviewer.

Results

A total of 2796 reports from 61 countries and regions were selected. Japanese researchers published the most papers (n=946), followed by those from China (n=747) and South Korea (n=557). Papers from Japan also had the most citations (n=21,836). Surgical Endoscopy and Other Interventional Techniques published the most reports on laparoscopic surgery for GC (n=386) and also had the highest total number of citations (n=11,076), making this journal the most authoritative in this field. Among the institutions, researchers from Seoul National University in South Korea had the highest numbers of published papers and citations. The keywords of the articles could be divided into five categories: surgical methods for GC, short-term and long-term efficacy of laparoscopic surgery, guiding role of laparoscopy in the treatment of advanced GC, diagnosis and treatment of early gastric cancer (EGC), and lymph node dissection. Keywords such as "laparoscopic proximal gastrectomy", "surgical outcomes", and "esophagogastric junction" have emerged recently, and relevant studies on laparoscopic surgery for adenocarcinoma of esophagogastric junction(AEG)have gradually become a hot topic and trend.

Conclusion

This study adopted bibliometric analysis to identify the current research hotspots and research trends in the field of laparoscopic surgery for GC. Five main research hotspots of laparoscopic surgery for GC were also identified. Laparoscopic surgery for AEG may become an important research focus in the future.

Study on naked eye tracing of inguinal sentinel lymph nodes in penile cancer patients with carbon nanoparticle suspension injection

Objective

Exploratory study of the effect and clinical value of carbon nanoparticle suspension injection (CNSI) as a tracer for inguinal sentinel lymph nodes in penile cancer.

Method

We selected 29 patients with penile cancer in our department from January 2019 to October 2022. According to whether the CNSI tracer was injected during the pathological biopsy of the inguinal lymph nodes, the enrolled patients were assigned to the control group, the group in which CNSI was injected 12 h before the surgery (12HBS group) and the group in which CNSI was injected 0.5 h before the surgery (0.5HBS group). Evaluating the effectiveness of CNSI as a lymphatic tracer involves analyzing the following: its safety, the statistical analysis of the detection rate (DR) of different groups, the number of lymph nodes sent for each case (NOLNSFEC), the difference of positive rate of lymphatic metastasis (PROLM), and operation time (OT).

Results

The lymph nodes in the 12HBS group and 0.5HBS group had an obvious black staining appearance, and no adverse reactions or surgical complications were found. Most of the black-stained areas caused by CNSI injection were removed with penile excision, which did not affect the postoperative appearance. This did not affect the pathological analysis. The DR of lymph nodes in the 12HBS group was higher (p < 0.05) than that in the control group. More lymph nodes were removed for examination (p < 0.05), which improved the efficiency of surgery. Compared with the 12HBS group, the number of lymph nodes removed in the 0.5HBS group decreased (p < 0.05). The OT was shortened (p < 0.05), but there was no significant difference in the DR and PROLM.

Conclusion

CNSI was applied to the naked-eye tracing of inguinal sentinel lymph nodes in penile cancer, which is safe and efficient. Injection of CNSI 0.5 h before surgery can help identify the "foremost position" of sentinel lymph nodes and reduce surgical trauma.

Tracers in Gastric Cancer Surgery

The treatment of gastric cancer mainly depends on radical gastrectomy. Determination of appropriate surgical margins and adequate lymph node (LN) resection are two major surgical steps that directly correlate with prognosis in gastric cancer. Due to the expanding use of minimally invasive procedures, it is no longer possible to locate tumors and LNs through touch. As an alternative, tracers have begun to enter the field due to their capacities for intraoperative visualization. Herein, we summarize the application of contemporary tracers in gastric cancer surgery, including isosulfan blue, methylene blue, patent blue, indocyanine green, carbon particles, and radioactive tracers. Their mechanisms, administration methods, detection efficiency, and challenges, as well as perspectives on them, are also outlined.

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.

[ICG lymph node mapping in cancer surgery of the upper gastrointestinal tract]

The importance of the assessment of the N‑status in gastric carcinoma, tumors of the gastroesophageal junction and esophageal cancer is undisputed; however, there is currently no internationally validated method for lymph node mapping in esophageal and gastric cancer. Near-infrared fluorescence imaging (NIR) is an innovative technique from the field of vibrational spectroscopy, which in combination with the fluorescent dye indocyanine green (ICG) enables intraoperative real-time visualization of anatomical structures. The ICG currently has four fields of application in oncological surgery: intraoperative real-time angiography for visualization of perfusion, lymphography for visualization of lymphatic vessels, visualization of solid tumors, and (sentinel) lymph node mapping. For imaging of the lymph drainage area and therefore the consecutive lymph nodes, peritumoral injection of ICG must be performed. Several studies have demonstrated the feasibility of peritumoral injection of ICG administered 15 min to 3 days preoperatively with subsequent intraoperative visualization of the lymph nodes. So far prospective randomized studies on the validation of the method are still lacking. In contrast, the use of ICG for lymph node mapping and visualization of sentinel lymph nodes in gastric cancer has been performed in large cohorts as well as in prospective randomized settings. Up to now, multicenter studies for ICG-guided lymph node mapping during oncological surgery of the upper gastrointestinal tract are lacking. Artificial intelligence methods can help to evaluate these techniques in an automated manner in the future as well as to support intraoperative decision making and therefore to improve the quality of oncological surgery.

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

Background

Indocyanine green (ICG) fluorescence imaging has been a new surgical navigation technique for gastric cancer. However, its clinical value should still be evaluated further. In this meta-analysis, we investigated the safety and efficacy of ICG near-infrared fluorescent imaging-guided lymph nodes (LNs) dissection during radical gastrectomy.

Methods

Studies comparing ICG fluorescence imaging with standard care in patients with gastric cancer were systematically searched from PubMed, Embase, Web of Science, and Cochrane Library through August 2021. The current meta-analysis was performed according to the preferred reporting items for systematic review and meta-analysis guidelines. A pooled analysis was performed for the available data regarding the number of LNs dissection, the number of metastatic LNs dissection, other operative outcomes, and postoperative complications. R software version 4.2.0 and Stata 16.0 software were used for the present meta-analysis.

Results

This analysis included 12 studies with a total of 1365 gastric cancer patients (569 in the ICG group and 796 in the non-ICG group). The number of retrieved LNs in the ICG group was significantly higher (weighted mean difference [WMD]=7.67, 95% confidence intervals [CI]: 4.73 to 10.62, P<0.05) compared to the non-ICG group with moderate heterogeneity (P<0.001, I2 = 70%). The number of metastatic LNs, operative time, and postoperative complications were all comparable and without significant heterogeneity. Additionally, ICG near-infrared fluorescent imaging was associated with reduced intraoperative blood loss (WMD=-10.28, 95% CI: -15.22 to -5.35, P<0.05) with low heterogeneity (P=0.07, I2 = 43%).

Conclusions

ICG near-infrared fluorescent imaging-guided lymphadenectomy was considered to be safe and effective in gastrectomy. ICG was used to increase the number of LNs harvested while reducing intraoperative blood loss without increasing operative time or postoperative complications.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021291863.

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.

Applicative Limitations of Indocyanine Green Fluorescence Assistance to Laparoscopic Lymph Node Dissection in Total Gastrectomy for Cancer

BACKGROUND

Indocyanine green (ICG) fluorescence has been recently introduced as a novel imaging technique improving the accuracy of lymph node (LN) dissection in gastric cancer (GC) surgery, although procedure standardization and achievements have not been clearly defined. This study analyzed the feasibility and effectiveness of ICG-guidance for laparoscopic D2-lymphadenectomy during total gastrectomy for cancer.

METHODS

This study retrospectively analyzed a single-center series of patients who underwent laparoscopic total gastrectomy for cancer between April 2015 and August 2021. All patients underwent surgery with standard D2 LN dissection. Intraoperative ICG-fluorescence was institutionally implemented in April 2018 and was performed routinely afterward. Primary outcomes were LN harvest and ratio. Secondary endpoints included operative time and subgroup analysis to assess variables potentially affecting LN retrieval.

RESULTS

The study population included 102 patients, and ICG-fluorescence was applied in 38 (37.3%). ICG and no-ICG groups presented similar median age, gender proportions, ASA score and comorbidities (age-adjusted Charlson Comorbidity Index), body mass index, and advanced pathological stage. The median of LNs retrieved was significantly higher after the intraoperative ICG-guidance (44 vs. 32; p = 0.004), although this association was not significant after neoadjuvant therapy or among patients with positive LNs. Lymph node ratio and operative time were not significantly impacted by ICG fluorescence. Multivariate analysis identified the ICG-assistance as the only independent determinant for LN harvest (p = 0.029).

CONCLUSIONS

ICG-guidance contributes to a significantly wider LN retrieval after laparoscopic D2-lymphadenectomy during total gastrectomy for cancer. However, neoadjuvant therapy and positive LN stage appeared to limit the procedural effectiveness to ICG-assisted LN identification.

Intraoperative fluorescence molecular imaging accelerates the coming of precision surgery in China

Purpose

China has the largest cancer population globally. Surgery is the main choice for most solid cancer patients. Intraoperative fluorescence molecular imaging (FMI) has shown its great potential in assisting surgeons in achieving precise resection. We summarized the typical applications of intraoperative FMI and several new trends to promote the development of precision surgery.

Methods

The academic database and NIH clinical trial platform were systematically evaluated. We focused on the clinical application of intraoperative FMI in China. Special emphasis was placed on a series of typical studies with new technologies or high-level evidence. The emerging strategy of combining FMI with other modalities was also discussed.

Results

The clinical applications of clinically approved indocyanine green (ICG), methylene blue (MB), or fluorescein are on the rise in different surgical departments. Intraoperative FMI has achieved precise lesion detection, sentinel lymph node mapping, and lymphangiography for many cancers. Nerve imaging is also exploring to reduce iatrogenic injuries. Through different administration routes, these fluorescent imaging agents provided encouraging results in surgical navigation. Meanwhile, designing new cancer-specific fluorescent tracers is expected to be a promising trend to further improve the surgical outcome.

Conclusions

Intraoperative FMI is in a rapid development in China. In-depth understanding of cancer-related molecular mechanisms is necessary to achieve precision surgery. Molecular-targeted fluorescent agents and multi-modal imaging techniques might play crucial roles in the era of precision surgery.

New Intraoperative Imaging Tools and Image-Guided Surgery in Gastric Cancer Surgery

Innovations and new advancements in intraoperative real-time imaging have gained significant importance in the field of gastric cancer surgery in the recent past. Currently, the most promising procedures include indocyanine green fluorescence imaging (ICG-FI) and hyperspectral imaging or multispectral imaging (HSI, MSI). ICG-FI is utilized in a broad range of clinical applications, e.g., assessment of perfusion or lymphatic drainage, and additional implementations are currently investigated. HSI is still in the experimental phase and its value and clinical relevance require further evaluation, but initial studies have shown a successful application in perfusion assessment, and prospects concerning non-invasive tissue and tumor classification are promising. The application of machine learning and artificial intelligence technologies might enable an automatic evaluation of the acquired image data in the future. Both methods facilitate the accurate visualization of tissue characteristics that are initially indistinguishable for the human eye. By aiding surgeons in optimizing the surgical procedure, image-guided surgery can contribute to the oncologic safety and reduction of complications in gastric cancer surgery and recent advances hold promise for the application of HSI in intraoperative tissue diagnostics.

OUP accepted manuscript

To date, there are no reports indicating the use of indocyanine green (ICG) fluorescence to detect pathologic lymphatic tissue when a laparoscopic lymph node biopsy (LLB) for suspected new or recurrent lymphoma is performed. We present the case of a 72-year-old female patient admitted for suspicion of recurrent lymphoma. A preoperative imaging work-up showed solid tissue enveloping the terminal portion of the abdominal aorta with a standardized uptake value (SUV) of 10. Therefore, an LLB was planned. After induction of anesthesia, a ICG solution was injected intravenously and subcutaneously at both inguinal regions. At laparoscopy, a complete visualization of the pathologic lymph nodes was achieved, enabling an incisional biopsy of the lymphomatous mass. LLB with ICG-fluorescence offers a simple and safe method for pathologic lymph node detection in the suspicion of intra-abdominal lymphoma. More studies with large case series are needed to confirm the efficacy of this application.

Laparoscopic lymph node biopsy for lymphoma with a novel use of indocyanine green fluorescence in a 66-year-old male patient

Introduction

Indocyanine green (ICG) near-infrared fluorescence is primarily employed in detecting Intraoperative sentinel lymph node (SLN) mapping or to evaluate the extent of radical lymphadenectomy mainly in colo-rectal and gastric cancer. To date there are no reports indicating the use of this dye to detect pathologic lymphatic tissue when a lymph node biopsy for suspected lymphoproliferative disease is performed.

Presentation of case

A 66-year-old male patient was admitted to the hospital for severe pain of left renal colic type. A computed tomography (CT) scan and a positron emission tomography (PET) showed a left hydroureteronephrosis due to ureter compression by paraortic solid tissue of lymphomatous aspect with a standardized uptake value (SUV) of 15. Multiple lymphadenopathies on paracaval, para-aortic and common iliac sites were present as well.

Discussion

A laparoscopic lymph node biopsy (LLB) was planned for diagnostic purposes. After induction of anesthesia a ICG solution was injected Intradermally at both inguinal regions. At laparoscopy a complete visualization of the pathologic lymphnodes was achieved, enabling incisional biopsies of the lymphomatous mass. Histopathological examination showed an extranodal localization of an aggressive B-cell non-Hodgkin lymphoma.

Conclusion

ICG-fluorescence seems to offer a simple and safe method for pathologic lymph node detection. LLB in the suspicion of intra abdominal lymphoma can largely take advantage by this novel opportunity not yet tested to date. More studies with large case series are needed to confirm the efficacy of ICG-fluorescence for detecting pathologic lymph nodes.

•

First report in literature concerning the use of indocyanine green (ICG) for laparoscopic lymph node biopsy

•

Periaortic and iliac lymph nodes visualized at PET as pathological, at laparoscopy turned out to be stained up by ICG.

•

Deep lymph nodes staining with ICG is possible by means of a preoperative injection of an ICG solution into the inguinal regions.

•

ICG-fluorescence seems to offer a useful, expeditious, and easy reproductible method for pathologic lymph node [[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19]] laparoscopic lymph node biopsy (LLB).