Near-infrared fluorescence-guided metastasectomy for hepatic gastrointestinal stromal tumor metastases using indocyanine green: A case report

Real-Time Navigation in Liver Surgery Through Indocyanine Green Fluorescence: An Updated Analysis of Worldwide Protocols and Applications

BACKGROUND

Indocyanine green (ICG) fluorescence has seen extensive application across medical and surgical fields, praised for its real-time navigation capabilities and low toxicity. Initially employed to assess liver function, ICG fluorescence is now integral to liver surgery, aiding in tumor detection, liver segmentation, and the visualization of bile leaks. This study reviews current protocols and ICG fluorescence applications in liver surgery, with a focus on optimizing timing and dosage based on clinical indications.

METHODS

Following PRISMA guidelines, we systematically reviewed the literature up to 27 January 2024, using PubMed and Medline to identify studies on ICG fluorescence used in liver surgery. A systematic review was performed to evaluate dosage and timing protocols for ICG administration.

RESULTS

Of 1093 initial articles, 140 studies, covering a total of 3739 patients, were included. The studies primarily addressed tumor detection (40%), liver segmentation (34.6%), and both (21.4%). The most common ICG fluorescence dose for tumor detection was 0.5 mg/kg, with administration occurring from days to weeks pre-surgery. Various near-infrared (NIR) camera systems were utilized, with the PINPOINT system most frequently cited. Tumor detection rates averaged 87.4%, with a 10.5% false-positive rate. Additional applications include the detection of bile leaks, lymph nodes, and vascular and biliary structures.

CONCLUSIONS

ICG fluorescence imaging has emerged as a valuable tool in liver surgery, enhancing real-time navigation and improving clinical outcomes. Standardizing protocols could further enhance ICG fluorescence efficacy and reliability, benefitting patient care in hepatic surgeries.

Application of indocyanine green fluorescence imaging in hepatobiliary surgery

Indocyanine green (ICG) is a fluorescent dye with an emission wavelength of about 840 nm, which is selectively absorbed by the liver after intravenous or bile duct injection, and then it is excreted into the intestines through the biliary system. With the rapid development of fluorescence laparoscopy, ICG fluorescence imaging is safe, feasible, and widely used in hepatobiliary surgery. ICG fluorescence imaging is of great significance in precise preoperative and intraoperative localization of liver lesions, real-time visualization of hepatic segmental anatomy, intrahepatic and extrahepatic biliary tract visualization, and liver transplantation. ICG fluorescence imaging facilitates efficient intraoperative hepatobiliary decision-making and improves the safety of minimally invasive hepatobiliary surgery. Advances in imaging systems will increase the use of fluorescence imaging as an intraoperative navigation tool, improving the safety and accuracy of open and laparoscopic/robotic hepatobiliary surgery. Herin, we have reviewed the status of ICG applications in hepatobiliary surgery, aiming to provide new insights for the development of hepatobiliary surgery.

Narrative Review on the Use of Indocyanine Green Fluorescence in Surgical Oncology

Indocyanine green (ICG) has emerged as a transformative tool for intraoperative imaging in the field of oncology, significantly improving the identification and localization of tumors, lymphatic structures and metastatic lesions. This narrative review aims to synthesize findings from a comprehensive range of studies that evaluate the efficacy, applications and limitations of ICG fluorescence-guided surgery across various surgical specialties, including colorectal, gynecologic and hepatobiliary oncology. We meticulously analyzed studies published from 2010 to the present, highlighting the technical aspects of ICG administration and imaging techniques as well as the quantitative metrics of success, such as detection rates and negative surgical margins. The review identifies a trend toward increasing use of ICG due to its ability to provide real-time feedback during surgery, thus facilitating more precise and minimally invasive procedures. Moreover, this review explores recent advancements in ICG applications, including multimodal imaging techniques that combine fluorescence with other imaging modalities, such as near-infrared imaging and preoperative imaging studies. These innovations hold promise for further enhancing surgical precision, improving patient outcomes and optimizing intraoperative decision-making. Limitations associated with ICG use, such as variability in fluorescence intensity among different tumor types and the challenge of quantifying the optimal dosage, are also discussed. In conclusion, this narrative review underscores the critical role of ICG fluorescence in modern surgical oncology and provides insights into future research directions aimed at refining its use and expanding its applicability. Potential avenues for investigation include standardized protocols for ICG administration, investigation of patient selection criteria and comprehensive evaluations of long-term outcomes associated with ICG-guided surgical procedures.

Indocyanine Green Fluorescence Navigation in Liver Surgery: A Systematic Review on Dose and Timing of Administration

BACKGROUND

Indocyanine green (ICG) fluorescence has proven to be a high potential navigation tool during liver surgery; however, its optimal usage is still far from being standardized.

METHODS

A systematic review was conducted on MEDLINE/PubMed for English articles that contained the information of dose and timing of ICG administration until February 2021. Successful rates of tumor detection and liver segmentation, as well as tumor/patient background and imaging settings were also reviewed. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN).

RESULTS

Out of initial 311 articles, a total of 72 manuscripts were obtained. The quality assessment of the included studies revealed usually low; only 9 articles got qualified as high quality. Forty articles (55%) focused on open resections, whereas 32 articles (45%) on laparoscopic and robotic liver resections. Thirty-four articles (47%) described tumor detection ability, and 25 articles (35%) did liver segmentation ability, and the others (18%) did both abilities. Negative staining was reported (42%) more than positive staining (32%). For tumor detection, majority used the dose of 0.5 mg/kg within 14 days before the operation day, and an additional administration (0.02-0.5 mg/kg) in case of longer preoperative interval. Tumor detection rate was reported to be 87.4% (range, 43%-100%) with false positive rate reported to be 10.5% (range, 0%-31.3%). For negative staining method, the majority used 2.5 mg/body, ranging from 0.025 to 25 mg/body. For positive staining method, the majority used 0.25 mg/body, ranging from 0.025 to 12.5 mg/body. Successful segmentation rate was 88.0% (range, 53%-100%).

CONCLUSION

The time point and dose of ICG administration strongly needs to be tailored case by case in daily practice, due to various tumor/patient backgrounds and imaging settings.

Intraoperative Near-Infrared Fluorescence Imaging with Indocyanine Green for Identification of Gastrointestinal Stromal Tumors (GISTs), a Feasibility Study

Simple Summary

Surgical resection plays a pivotal role in the treatment of GIST patients. The current study aims to explore the use of near-infrared fluorescence imaging to optimize the intraoperative tumor identification of GISTs. For this purpose, the potential and limitations of the widely used, and non-specific, tracer indocyanine green were assessed in a multicenter study including 10 patients. Our results show that GISTs typically have similar fluorescence intensity to the surrounding tissue, within several minutes after the intravenous administration of indocyanine green. These findings justify future research into specific fluorescent tracers for GISTs, and set a reference for future intraoperative imaging trials.

Abstract

Background: Optimal intraoperative tumor identification of gastrointestinal stromal tumors (GISTs) is important for the quality of surgical resections. This study aims to assess the potential of near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) to improve intraoperative tumor identification. Methods: Ten GIST patients, planned to undergo resection, were included. During surgery, 10 mg of ICG was intravenously administered, and NIRF imaging was performed at 5, 10, and 15 min after the injection. The tumor fluorescence intensity was visually assessed, and tumor-to-background ratios (TBRs) were calculated for exophytic lesions. Results: Eleven GIST lesions were imaged. The fluorescence intensity of the tumor was visually synchronous and similar to the background in five lesions. In one lesion, the tumor fluorescence was more intense than in the surrounding tissue. Almost no fluorescence was observed in both the tumor and healthy peritoneal tissue in two patients with GIST lesions adjacent to the liver. In three GISTs without exophytic growth, no fluorescence of the tumor was observed. The median TBRs at 5, 10, and 15 min were 1.0 (0.4–1.2), 1.0 (0.5–1.9), and 0.9 (0.7–1.2), respectively. Conclusion: GISTs typically show similar fluorescence intensity to the surrounding tissue in NIRF imaging after intraoperative ICG administration. Therefore, intraoperatively administered ICG is currently not applicable for adequate tumor identification, and further research should focus on the development of tumor-specific fluorescent tracers for GISTs.

Fluorescence Guided Surgery

Fluorescence guided surgery (FGS) is an imaging technique that allows the surgeon to visualise different structures and types of tissue during a surgical procedure that may not be as visible under white light conditions. Due to the many potential advantages of fluorescence guided surgery compared to more traditional clinical imaging techniques such as its higher contrast and sensitivity, less subjective use, and ease of instrument operation, the research interest in fluorescence guided surgery continues to grow over various key aspects such as fluorescent probe development and surgical system development as well as its potential clinical applications. This review looks to summarise some of the emerging opportunities and developments that have already been made in fluorescence guided surgery in recent years while highlighting its advantages as well as limitations that need to be overcome in order to utilise the full potential of fluorescence within the surgical environment.