Diagnostic accuracy of indocyanine green fluorescence imaging and multidetector row computed tomography for identifying hepatocellular carcinoma with liver explant correlation

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.

Mechanisms of delayed indocyanine green fluorescence and applications to clinical disease processes

BACKGROUND

Delayed indocyanine green fluorescence imaging is under investigation in various clinical disease processes. Understanding the mechanisms of indocyanine green accumulation and retention is essential to correctly interpreting and analyzing imaging data. The purpose of this scoping review was to synthesize what is known about the mechanism of indocyanine green retention at the cellular level to better understand the clinical nuances of delayed indocyanine green imaging and identify critical gaps in our knowledge to guide future studies.

METHODS

We performed a scoping review of 7,087 citations after performing database searches of PubMed, Scopus, the Cochrane Library, and the Web of Science Core Collection electronic databases. Studies were eligible for inclusion if they were peer-reviewed original research discussing the mechanism of indocyanine green retention in the results section in disease processes involving inflammation and/or necrosis, including cancer, and were available in English. Data were extracted using Covidence software.

RESULTS

Eighty-nine studies were included in the final analysis. Several features of indocyanine green retention were identified.

CONCLUSION

We identified several mechanistic features involved in indocyanine green accumulation in diseased tissue that overall had distinct mechanisms of indocyanine green retention in tumors, nontumor inflammation, and necrosis. Our study also reveals new insights on how inflammatory infiltrate influences indocyanine green fluorescence imaging. These findings are noteworthy because they add to our understanding of how fluorescence-guided surgery may be optimized based on the pathology of interest via specific indocyanine green dosing and timing of image acquisition.

Hepatic epithelioid hemangioendothelioma a case report and literature review

INTRODUCTION

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare disease with a high probability of being misdiagnosed.

CASE PRESENTATION

We present a case of a 38-year-old female patient found with HEHE by physical examination. The tumor was removed by surgery successfully, but then had recurrence after the operation.

CLINICAL DISCUSSION

We review the current literature on HEHE; its prevalence, diagnosis and treatment. And our opinion is that using fluorescent laparoscopy for HEHE may has an advantage in visualizing tumors, but there is still high possibility of false positives. It is recommended to use it correctly during operation.

CONCLUSION

The clinical presentation, laboratory and imaging index for HEHE were lacking in specificity. Therefore, diagnosis still depends mainly on pathology results, in which the most effective treatment is surgery. Besides, the fluorescent nodule which is not shown on images need to be analyzed carefully in order to avoid damage to normal tissue.

Added value of indocyanine green fluorescence imaging in liver surgery

Recently, indocyanine green (ICG) fluorescence imaging has been widely used as a substitute for cholangiography in hepatobiliary surgery, to detect hepatic tumors, for accurate anatomical hepatectomy, and to increase the safety and accuracy of minimally invasive (laparoscopic and robotic) hepatectomy. The clinical relevance of this method has been increasing gradually, as new procedures develop in this field. Various important roles and the latest added value of ICG fluorescence imaging in liver surgery are discussed in this report.

Proof of concept of improved fluorescence-guided surgery of colon cancer liver metastasis using color-coded imaging of a tumor-labeling fluorescent antibody and indocyanine green restricted to the adjacent liver segment

BACKGROUND

Indocyanine green has been used for fluorescence-guided surgery of liver metastasis and labeling of liver segments. However, indocyanine green is nonspecific, and indocyanine green labeling does not always clearly outline tumor margins. In addition, it is difficult to distinguish between a tumor and its adjacent liver segment colored with indocyanine green alone. In the present study, we performed fluorescence-guided surgery in an orthotopic colon-cancer liver metastasis mouse model by labeling the metastatic liver tumor with an anti-carcinoembryonic antigen fluorescent antibody and with indocyanine green restricted to the adjacent liver segment.

METHODS

A liver metastasis model was established with human LS174T colon cancer tumor fragments. To label the tumor, mice received SGM-101, an anti-carcinoembryonic antigen antibody conjugated to a near-infrared fluorophore (700 nm), currently in clinical trials, 3 days before surgery. Indocyanine green (800 nm) was injected after ligation of the tumor-bearing Glissonean pedicle with fluorescence labeling restricted to the liver segment adjacent to the tumor. Bright-light surgery and fluorescence-guided surgery were performed to resect the liver metastasis. To assess recurrence, mice underwent necropsy 3 weeks after surgery and the tumor was weighed.

RESULTS

Fluorescence-guided anatomic left lateral lobectomy and fluorescence-guided partial liver resection were both performed with color-coded double labeled imaging. Tumor weight 3 weeks after surgery was significantly lower with fluorescence-guided surgery compared to bright-light surgery (38 ± 57 mg vs 836 ± 668 mg, P = .011) for partial liver resection.

CONCLUSION

The present study provides a proof-of-concept that color-coded and double labeling of the tumor and adjacent liver segment has the potential to improve liver metastasectomy.

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.

Computed tomography for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease

BACKGROUND

Hepatocellular carcinoma occurs mostly in people with chronic liver disease and ranks sixth in terms of global incidence of cancer, and fourth in terms of cancer deaths. In clinical practice, computed tomography (CT) is used as a second-line diagnostic imaging modality to confirm the presence of focal liver lesions suspected as hepatocellular carcinoma on prior diagnostic test such as abdominal ultrasound or alpha-foetoprotein, or both, either in surveillance programmes or in clinical settings. According to current guidelines, a single contrast-enhanced imaging study CT or magnetic resonance imaging (MRI) showing typical hallmarks of hepatocellular carcinoma in people with cirrhosis is valid to diagnose hepatocellular carcinoma. However, a significant number of hepatocellular carcinomas do not show typical hallmarks on imaging modalities, and hepatocellular carcinoma is, therefore, missed. There is no clear evidence of the benefit of surveillance programmes in terms of overall survival: the conflicting results can be a consequence of inaccurate detection, ineffective treatment, or both. Assessing the diagnostic accuracy of CT may clarify whether the absence of benefit could be related to underdiagnosis. Furthermore, an assessment of the accuracy of CT in people with chronic liver disease, who are not included in surveillance programmes is needed for either ruling out or diagnosing hepatocellular carcinoma.

OBJECTIVES

Primary: to assess the diagnostic accuracy of multidetector, multiphasic contrast-enhanced CT for the diagnosis of hepatocellular carcinoma of any size and at any stage in adults with chronic liver disease, either in a surveillance programme or in a clinical setting. Secondary: to assess the diagnostic accuracy of CT for the diagnosis of resectable hepatocellular carcinoma in adults with chronic liver disease.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Trials Register, Cochrane Hepato-Biliary Diagnostic-Test-Accuracy Studies Register, the Cochrane Library, MEDLINE, Embase, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index - Science until 4 May 2021. We applied no language or document-type restrictions.

SELECTION CRITERIA

Studies assessing the diagnostic accuracy of CT for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, with cross-sectional designs, using one of the acceptable reference standards, such as pathology of the explanted liver and histology of resected or biopsied focal liver lesion with at least a six-month follow-up.

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened studies, extracted data, and assessed the risk of bias and applicability concerns, using the QUADAS-2 checklist. We presented the results of sensitivity and specificity, using paired forest plots, and tabulated the results. We used a hierarchical meta-analysis model where appropriate. We presented uncertainty of the accuracy estimates using 95% confidence intervals (CIs). We double-checked all data extractions and analyses.

MAIN RESULTS

We included 21 studies, with a total of 3101 participants. We judged all studies to be at high risk of bias in at least one domain because most studies used different reference standards, often inappropriate to exclude the presence of the target condition, and the time-interval between the index test and the reference standard was rarely defined. Regarding applicability in the patient selection domain, we judged 14% (3/21) of studies to be at low concern and 86% (18/21) of studies to be at high concern owing to characteristics of the participants who were on waiting lists for orthotopic liver transplantation. CT for hepatocellular carcinoma of any size and stage: sensitivity 77.5% (95% CI 70.9% to 82.9%) and specificity 91.3% (95% CI 86.5% to 94.5%) (21 studies, 3101 participants; low-certainty evidence). CT for resectable hepatocellular carcinoma: sensitivity 71.4% (95% CI 60.3% to 80.4%) and specificity 92.0% (95% CI 86.3% to 95.5%) (10 studies, 1854 participants; low-certainty evidence). In the three studies at low concern for applicability (861 participants), we found sensitivity 76.9% (95% CI 50.8% to 91.5%) and specificity 89.2% (95% CI 57.0% to 98.1%). The observed heterogeneity in the results remains mostly unexplained. The sensitivity analyses, which included only studies with clearly prespecified positivity criteria and only studies in which the reference standard results were interpreted without knowledge of the results of the index test, showed no variation in the results.

AUTHORS' CONCLUSIONS

In the clinical pathway for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, CT has roles as a confirmatory test for hepatocellular carcinoma lesions, and for staging assessment. We found that using CT in detecting hepatocellular carcinoma of any size and stage, 22.5% of people with hepatocellular carcinoma would be missed, and 8.7% of people without hepatocellular carcinoma would be unnecessarily treated. For resectable hepatocellular carcinoma, we found that 28.6% of people with resectable hepatocellular carcinoma would improperly not be resected, while 8% of people without hepatocellular carcinoma would undergo inappropriate surgery. The uncertainty resulting from the high risk of bias in the included studies and concerns regarding their applicability limit our ability to confidently draw conclusions based on our results.

Electromagnetic Tracking and Optical Molecular Imaging Guidance for Liver Biopsy and Point-of-Care Tissue Assessment in Phantom and Woodchuck Hepatocellular Carcinoma

PURPOSE

To evaluate an integrated liver biopsy platform that combined CT image fusion, electromagnetic (EM) tracking, and optical molecular imaging (OMI) of indocyanine green (ICG) to target hepatocellular carcinoma (HCC) lesions and a point-of-care (POC) OMI to assess biopsy cores, all based on tumor retention of ICG compared to normal liver, in phantom and animal model.

MATERIAL

A custom CT image fusion and EM-tracked guidance platform was modified to integrate the measurement of ICG fluorescence intensity signals in targeted liver tissue with an OMI stylet or a POC OMI system. Accuracy was evaluated in phantom and a woodchuck with HCC, 1 day after administration of ICG. Fresh biopsy cores and paraffin-embedded formalin-fixed liver tissue blocks were evaluated with the OMI stylet or POC system to identify ICG fluorescence signal and ICG peak intensity.

RESULTS

The mean distance between the initial guided needle delivery location and the peak ICG signal was 5.0 ± 4.7 mm in the phantom. There was complete agreement between the reviewers of the POC-acquired ICG images, cytology, and histopathology in differentiating HCC-positive from HCC-negative biopsy cores. The peak ICG fluorescence intensity signal in the ex vivo liver blocks was 39 ± 12 and 281 ± 150 for HCC negative and HCC positive, respectively.

CONCLUSION

Biopsy guidance with fused CT imaging, EM tracking, and ICG tracking with an OMI stylet to detect HCC is feasible. Immediate assessment of ICG uptake in biopsy cores with the POC OMI system is feasible and correlates with the presence of HCC in the tissue.

The application of indocyanine green-fluorescence imaging during robotic-assisted liver resection for malignant tumors: a single-arm feasibility cohort study

BACKGROUND

The fluorescence properties of Indocyanine Green (ICG) make it a useful technique in the armamentarium of liver surgeons in order to enhance the visualization of anatomical structures by providing a real-time liver mapping.

METHODS

We have analyzed the impact of ICG-fluorescence staining technique in 40 consecutive patients who underwent robotic-assisted liver resection for malignancies from June 2014 to November 2017.

RESULTS

For the 55% of patients the surgical indication was colorectal liver metastasis followed by hepatocarcinoma in 35% of cases. The R0 resection rate was 100%, and the mean resection margin was 12 mm. Twenty percent of patients experienced tumor recurrence. The 1-year and 2-year overall survival rates were 91% and 84%, respectively. The 1-year and 2-year disease free survival were 77.2% and 65%, respectively. The previously marked transaction line was changed after the staining method in 12 out of 40 patients. Through intra-operative ultrasonography and white-light exploration of the liver surface 43 lesions were detected, whereas with the ICG-F 52 lesion of the liver surface were identified, including two superficial colorectal metastases missed at the intra-operative ultrasonography.

CONCLUSION

The ICG-F is a promising navigational tool, that can potentially overcome the limitations of the minimally invasive liver surgery.

[Three-dimensional visualization combined with indocyanine green fluorescence imaging in diagnosis and treatment of primary hepatocellular carcinoma]

OBJECTIVE

To explore the value of three-dimensional visualization technology (3DVT) combined with indocyanine green (ICG) fluorescence imaging in the diagnosis and treatment of primary hepatocellular carcinoma (HCC).

METHODS

We retrospectively analyzed the clinical data of 154 patients with HCC admitted to the Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University between January, 2016 and November, 2018. In 57 of the patients (3DVT group), preoperative CT and Gd-EOB-DTPA-enhanced MRI were performed and 3D visualization and surgical planning was carried out before the operation; intraoperative ICG florescence imaging was performed for real-time detection of the tumor location and demarcation, intrahepatic satellite lesions and metastases. According to the intraoperative fluorescent signals and 3D visualization-based surgical planning, the final surgical plan was determined. In the other 97 patients (control group), conventional surgical assessment and surgical resection of the tumor was carried out. The preoperative imaging findings, intraoperative tumor detection, postoperative laboratory results, pathological reports, and follow-up data of the patients were analyzed.

RESULTS

In 3DVT group, 63 and 70 lesions were detected by preoperative CT and MRI, respectively; compared with CT examination, intraoperative ICG florescence imaging revealed additional 17 lesions, among which 10 were pathologically confirmed as HCC and 7 as cirrhosis nodules. The median volume of bleeding was 300 mL in 3DVT group, significantly less than that in the control group (400 mL; Z=2.291, P=0.022). In both groups, serious complications or perioperative death occurred in none of the patients. The incidence of postoperative complications was significantly lowed in 3DVT group than in the control group [21% (12/57) vs 48.4% (47/97); χ2=11.406, P=0.001]. The overall disease-free survival rate at 2 years after the operation was significantly higher in 3DVT group than in the control group (74.9% vs 28.9%, P=0.022).

CONCLUSIONS

3DVT combined with ICG fluorescence imaging allows precise preoperative diagnosis, surgical planning and implementation, intraoperative detection of small liver cancers and precise navigation for HCC treatment, thereby helping to reduce postoperative complications and improve the disease-free survival rate of the patients.

Living Donor Liver Re-Transplantation for Recurrent Hepatoblastoma in the Liver Graft following Complete Eradication of Peritoneal Metastases under Indocyanine Green Fluorescence Imaging

The curability of chemotherapy-resistant hepatoblastoma (HB) largely depends on the achievement of radical surgical resection. Navigation techniques utilizing indocyanine green (ICG) are a powerful tool for detecting small metastatic lesions. We herein report a patient who underwent a second living donor liver transplantation (LDLTx) for multiple recurrent HBs in the liver graft following metastasectomy for peritoneal dissemination with ICG navigation. The patient initially presented with ruptured HB at 6 years of age and underwent 3 liver resections followed by the first LDLTx with multiple sessions of chemotherapy at 11 years of age. His alpha-fetoprotein (AFP) level increased above the normal limit, and metastases were noted in the transplanted liver and peritoneum four years after the first LDLTx. The patient underwent metastasectomy of the peritoneally disseminated HBs with ICG navigation followed by the second LDLTx for multiple metastases in the transplanted liver. The patient has been recurrence-free with a normal AFP for 30 months since the second LDLTx. To our knowledge, this report is the first successful case of re-LDLTx for recurrent HBs. Re-LDLTx for recurrent HB can be performed in highly select patients, and ICG navigation is a powerful surgical tool for achieving tumor clearance.

Improving the Surgical Effect for Primary Liver Cancer with Intraoperative Fluorescence Navigation Compared with Intraoperative Ultrasound

BACKGROUND This study aimed to compare the application value of intraoperative fluorescence navigation technology (FNT) and intraoperative ultrasound (IOUS) in primary liver cancer surgery. MATERIAL AND METHODS Fifty consecutive patients with primary liver cancer scheduled to receive surgical treatment were divided into FNT group and IOUS group. FNT and IOUS were separately used to guide tumor resection and detect new cancerous lesions in the 2 groups. The complete tumor resection rate (R0) resection rate, length of the tumor distance from cutting edge, the diagnostic efficacy of cancerous nodules and the fluorescence imaging characteristics of different types tumors were recorded. RESULTS The R0 resection rate was 100% (25 out of 25 patients) in the FNT group and 96% (24 out of 25 patients) in the IOUS group. In the FNT group, 1 case (4%, 1 out of 25 patients) had cancer tissue that was less than 1 cm from the cutting edge, compared to 7 cases (28%, 7 out of 25 patients) in the IOUS group (P=0.049), which was a significant difference. In the remaining livers of 50 consecutive patients, FNT found 5 new cancerous nodules with a sensitivity of 71.4%, a specificity of 11.1%, and a false-positive rate of 88.9%; for IOUS the results were 42.9%, 88.9%, 11.1%. The fluorescence imaging characteristics of all well-differentiated hepatocellular carcinomas were tumor tissue imaging, but all other types of tumors were ring imaging around the tumor. CONCLUSIONS FNT can improve the R0 resection rate, ensure a safe distance between tumor and cutting edge and can identify more new cancerous nodules compared to IOUS. Thus, FNT could improve the surgical treatment effect for primary liver cancer and hopefully further improve the prognosis of patients.

A practical guide for the use of indocyanine green and methylene blue in fluorescence-guided abdominal surgery

Near-infrared (NIR) fluorescence imaging is gaining clinical acceptance over the last years and has been used for detection of lymph nodes, several tumor types, vital structures and tissue perfusion. This review focuses on NIR fluorescence imaging with indocyanine green and methylene blue for different clinical applications in abdominal surgery with an emphasis on oncology, based on a systematic literature search. Furthermore, practical information on doses, injection times, and intraoperative use are provided.

Optical Imaging Paves the Way for Autophagy Research

Autophagy is a degradation process in eukaryotic cells that recycles cellular components for nutrition supply under environmental stress and plays a double-edged role in development of major human diseases. Noninvasive optical imaging enables us to clearly visualize various classes of structures involved in autophagy at macroscopic and microscopic dynamic levels. In this review, we discuss important trends of emerging optical imaging technologies used to explore autophagy and provide insights into the mechanistic investigation and structural study of autophagy in mammalian cells. Some exciting new prospects and future research directions regarding optical imaging techniques in this field are also highlighted.