A narrative review of near-infrared fluorescence imaging in hepatectomy for hepatocellular carcinoma

Theranostic Fluorescent Probes

The ability to gain spatiotemporal information, and in some cases achieve spatiotemporal control, in the context of drug delivery makes theranostic fluorescent probes an attractive and intensely investigated research topic. This interest is reflected in the steep rise in publications on the topic that have appeared over the past decade. Theranostic fluorescent probes, in their various incarnations, generally comprise a fluorophore linked to a masked drug, in which the drug is released as the result of certain stimuli, with both intrinsic and extrinsic stimuli being reported. This release is then signaled by the emergence of a fluorescent signal. Importantly, the use of appropriate fluorophores has enabled not only this emerging fluorescence as a spatiotemporal marker for drug delivery but also has provided modalities useful in photodynamic, photothermal, and sonodynamic therapeutic applications. In this review we highlight recent work on theranostic fluorescent probes with a particular focus on probes that are activated in tumor microenvironments. We also summarize efforts to develop probes for other applications, such as neurodegenerative diseases and antibacterials. This review celebrates the diversity of designs reported to date, from discrete small-molecule systems to nanomaterials. Our aim is to provide insights into the potential clinical impact of this still-emerging research direction.

Engineering a near-infrared LAP fluorescent probe with high sensitivity and selectivity for surgical resection of liver cancer

Hepatocellular carcinoma (HCC) is a type of cancer associated with a high rate of mortality and morbidity. In order to achieve precise HCC theranostics, it is important to develop excellent fluorescent probes. However, the existing probes are not sensitive or specific enough to accurately identify HCC margins and contours. For diagnosing HCC and identifying tumors during surgery, it is urgent to engineer highly sensitive and selective fluorescent probes. Liver tumor progression is closely associated with leucine aminopeptidase (LAP) overexpression, a biomarker of liver cancer. Herein, we have rationally designed a NIR fluorescent probe, NLAP, which is specially activated by LAP. The probe exhibited high sensitivity (detection limit = 6.8 mU L-1) and superior affinity (Km = 2.98 μM) for LAP. With this probe, we distinguished cancer cells overexpressing LAP from normal cells and applied it intraoperatively to guide liver tumor excisions. Furthermore, NLAP was employed to successfully detect the LAP of intestinal and splenic metastatic tumors in orthotopic liver tumor mice by "in situ spraying" and good performances were demonstrated.

Assessment of a novel biliary-specific near-infrared fluorescent dye (BL-760) for intraoperative detection of bile ducts and biliary leaks during hepatectomy in a preclinical swine model

OBJECTIVES

Postoperative bile leakage is a common complication of hepatobiliary surgery and frequently requires procedural intervention. Bile-label 760 (BL-760), a novel near-infrared dye, has emerged as a promising tool for identifying biliary structures and leakage, owing to its rapid excretion and strong bile specificity. This study aimed to assess the intraoperative detection of biliary leakage using intravenously administered BL-760 compared with intravenous (IV) and intraductal (ID) indocyanine green (ICG).

MATERIALS AND METHODS

Laparotomy and segmental hepatectomy with vascular control were performed on two 25-30 kg pigs. ID ICG, IV ICG, and IV BL-760 were administered separately, followed by an examination of the liver parenchyma, cut liver edge, and extrahepatic bile ducts for areas of leakage. The duration of intra- and extrahepatic fluorescence detection was assessed, and the target-to-background (TBR) of the bile ducts to the liver parenchyma was quantitatively measured.

RESULTS

In Animal 1, after intraoperative BL-760 injection, three areas of leaking bile were identified within 5 min on the cut liver edge with a TBR of 2.5-3.8 that was not apparent to the naked eye. In contrast, after IV ICG administration, the background parenchymal signal and bleeding obscured the areas of bile leakage. A second dose of BL-760 demonstrated the utility of repeated injections, confirming two of the three previously visualized areas of bile leakage and revealing one previously unseen leak. In Animal 2, neither ID ICG nor IV BL-760 injections showed obvious areas of bile leakage. However, fluorescence signals were observed within the superficial intrahepatic bile ducts after both injections.

CONCLUSIONS

BL-760 enables the rapid intraoperative visualization of small biliary structures and leaks, with the benefits of fast excretion, repeatable intravenous administration, and high-fluorescence TBR in the liver parenchyma. Potential applications include the identification of bile flow in the portal plate, biliary leak or duct injury, and postoperative monitoring of drain output. A thorough assessment of the intraoperative biliary anatomy could limit the need for postoperative drain placement, a possible contributor to severe complications and postoperative bile leak.

Near-infrared fluorescence imaging of hepatocellular carcinoma cells regulated by β-catenin signaling pathway

Background

Near-infrared fluorescence (NIRF) imaging has recently emerged as a promising tool for noninvasive cancer imaging. However, lack of tumor sensitivity and specificity restricts the application of NIRF dyes in surgical navigation.

Methods

Herein, we investigated the imaging features of NIRF dye MHI-148 and indocyanine green (ICG) in live cell imaging and xenograft nude mice models. TCGA dataset analysis and immunohistochemistry were conducted to investigate the expression of OATPs or ABCGs in hepatocellular carcinoma (HCC) tissues. OATPs or ABCGs were knocked down and overexpressed in HCC cells using transient transfection by siRNA and plasmids or stable transfection by lentivirus. Further, qRT-PCR ,Western blotting and the use of agonists or inhibitors targeting β-catenin signaling pathway were applied to explore its important role in regulation of OATP2B1 and ABCG2 expression.

Results

Here we demonstrated that NIRF dye MHI-148 was biocompatible as indocyanine green (ICG) but with higher imaging intensity and preferential uptake and retention in hepatocellular carcinoma (HCC) cells and tissues. Moreover, our data indicated that membrane transporters OATP2B1 and ABCG2, which regulated by β-catenin signaling pathway, mediated tumor-specific accumulation and retention of MHI-148 in HCC cells. In addition, the treatment with β-catenin inhibitor significantly enhanced the accumulation of MHI-148 in HCC tissues and improved the efficacy of tumor imaging with MHI-148 in vivo.

Conclusions

Our study uncovers a mechanism that links the distribution and expression of the membrane transporters OATP2B1 and ABCG2 to the tumor-specific accumulation of MHI-148, and provides evidence supporting a regulating role of the β-catenin signaling pathway in OATP2B1 and ABCG2- induced retention of MHI-148 inHCC tissues, and strategy targeting key components of MHI-148 transport machinery may be a potential approach to improve HCC imaging.

Laparoscopic Microwave Ablation: Which Technologies Improve the Results

Liver resection is the best treatment for hepatocellular carcinoma (HCC) when resectable. Unfortunately, many patients with HCC cannot undergo liver resection. Percutaneous thermoablation represents a valid alternative for inoperable neoplasms and for small HCCs, but it is not always possible to accomplish it. In cases where the percutaneous approach is not feasible (not a visible lesion or in hazardous locations), laparoscopic thermoablation may be indicated. HCC diagnosis is commonly obtained from imaging modalities, such as CT and MRI, However, the interpretation of radiological images, which have a two-dimensional appearance, during the surgical procedure and in particular during laparoscopy, can be very difficult in many cases for the surgeon who has to treat the tumor in a three-dimensional environment. In recent years, more technologies have helped surgeons to improve the results after ablative treatments. The three-dimensional reconstruction of the radiological images has allowed the surgeon to assess the exact position of the tumor both before the surgery (virtual reality) and during the surgery with immersive techniques (augmented reality). Furthermore, indocyanine green (ICG) fluorescence imaging seems to be a valid tool to enhance the precision of laparoscopic thermoablation. Finally, the association with laparoscopic ultrasound with contrast media could improve the localization and characteristics of tumor lesions. This article describes the use of hepatic three-dimensional modeling, ICG fluorescence imaging and laparoscopic ultrasound examination, convenient for improving the preoperative surgical preparation for personalized laparoscopic approach.

Efficacy evaluation and prognostic risk factors analysis of precise hepatectomy in the treatment of intermediate and advanced hepatocellular carcinoma

BACKGROUND

To investigate the efficacy of precise hepatectomy in the treatment of patients with intermediate and advanced hepatocellular carcinoma and analyze the risk factors affecting prognosis.

METHODS

Totally 104 patients with intermediate and advanced hepatocellular carcinoma from January 2018 to January 2019 were enrolled in this retrospective analysis. Of these, four patients lost to follow-up. Logistic regression was conducted to explore the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Compared with the control group, the precise hepatectomy decreased intraoperative blood loss (331.2928.91 to 203.29 ± 29.34 ml), operation time (198.29 ± 19.38 to 150.28 ± 18.27 min), perioperative blood transfusion volume (376.22 ± 25.93 to 228.29 ± 22.19 ml) (all P < 0.001). Logistic regression analysis of study group showed that hepatitis B infection (OR  = 1.746; 95% CI, 1.068-2.976), P  =  0.021, Child-Pugh classification (OR  =  2.319; 95% CI, 1.428-3.213), P < 0.001, Eastern Cooperative Oncology Group (ECOG) score (OR  =  2.287; 95% CI, 1.098-3.876; P  =  0.013) and Barcelona-Clinic Liver Cancer (BCLC) staging (OR = 2.029; 95% CI, 1.086-3.671; P = 0.022) were independent risk factors for prognosis of the precise hepatectomy.

CONCLUSION

Hepatitis B virus infection, Child-Pugh grade, ECOG score and BCLC staging grade were the independent risk factors affecting the prognosis of precise hepatectomy.

First clinical applications for the NIR-II imaging with ICG in microsurgery

In microsurgery, it is always difficult to accurately identify the blood supply with ease, such as vascular anastomosis, digit replantation, skin avulsion reconstruction and flap transplantation. Near-infrared window I (NIR-I, 700—900 nm) imaging has many clinical applications, whereas near-infrared window II (NIR-II, 1,000–1700 nm) imaging has emerged as a highly promising novel optical imaging modality and used in a few clinical fields recently, especially its penetration distance and noninvasive characteristics coincide with the needs of microsurgery. Therefore, a portable NIR-II imaging instrument and the Food and Drug Administration (FDA) approved indocyanine green (ICG) were used to improve the operation efficiency in microsurgery of 39 patients in this study. The anastomotic vessels and the salvaged distal limbs were clearly visualized after intravenous injection of ICG. The technique enabled identification of perforator vessels and estimation of perforator areas prior to the flap obtention and made it easier to monitor the prognosis. Overall, this study highlights the use of the portable NIR- II imaging with ICG as an operative evaluation tool can enhance the safety and accuracy of microsurgery.

Multiradiographic Diagnosis of Primary Hepatocellular Carcinoma and Evaluation of Its Postoperative Observation after Interventional Treatment

Objective

To investigate the focal imaging performance of MRI and CT multiphase dynamic enhancement scan examination in primary liver cancer patients, analyze its clinical diagnostic value, and provide a basis for early diagnosis of the disease.

Methods

236 patients with primary liver cancer admitted to our hospital from May 2019 to November 2021 were randomly divided into two groups, the control group was given MRI multiphase dynamic enhancement scan diagnostic method, and the observation group was given CT scan combined with the MRI diagnostic method. The patients' examination results and pathological examination results were compared and analyzed, and the therapeutic effects of patients in the two groups after interventional treatment were compared.

Results

After the imaging and pathological examinations of patients in both groups, it was found that the diagnostic accuracy of patients in the observation group and the therapeutic effect after interventional treatment were significantly better than those in the control group.

Conclusions

Compared with CT multiphase dynamic enhancement scan, MRI multiphase dynamic enhancement scan can show multidirectional and multiangle lesions in primary hepatocellular carcinoma patients, with better characteristics of blood supply to hepatocellular carcinoma and a higher accuracy rate.

Comparison of the efficacy and safety of repeated hepatectomy and radiofrequency ablation in the treatment of primary recurrent liver cancer: a meta-analysis

Background

Since there is still controversy about the comparison of the efficacy and safety of RH and RFA in the treatment of recurrent liver cancer, we conducted a meta-analysis to compare the efficacy and safety, in order to provide evidence-based evidence for future research and clinical treatment.

Methods

We searched PubMed, Embase, and Cochrane Library from the establishment of the database to Feb 2021. We included studies that reported liver cancer patients underwent repeated hepatectomy (RH) or radiofrequency ablation (RFA), and we excluded duplicate publications, research without full text, incomplete information, or inability to conduct data extraction, animal experiments, reviews, and systematic reviews. The STATA 15.1 was used to analyze the data.

Results

The pooled results show that the 3-year and 5-year overall survival (OS) rate of the repeated hepatectomy group was significantly higher than the radiofrequency ablation group (odds ratio (OR) = 1.95, 95% confidence interval (CI):1.47–2.60, P ≤ 0.001; OR = 1.65, 95% CI: 1.12–2.43, P = 0.012). Similarly, the pooled results show that the 3-year and 5-year disease-free survival (DFS) rate of the repeated hepatectomy group was significantly higher than the radiofrequency ablation group (OR = 1.73, 95% CI: 1.30–2.31, P ≤ 0.001; OR = 1.84, 95% CI: 1.38–2.49, P ≤ 0.001). However, there is no significant difference in the 1-year OS and DFS rate of repeated hepatectomy group and radiofrequency ablation group. Additionally, the pooled results show that the postoperative Clavien-Dindo (CD) grade II or higher complication rate of the repeated hepatectomy group was significantly higher than the radiofrequency ablation group (OR = 2.80, 95% CI: 1.37–5.75, P = 0.005).

Conclusion

Based on the pooled results of 8 existing retrospective studies, RH has a higher OS rate and DFS rate in the treatment of recurrent liver cancer, while the postoperative complication rate of RFA is lower. When survival is the primary goal, RH should be the first choice for recurrent liver cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02649-4.

A clinical trial of super-stable homogeneous lipiodol-nanoICG formulation-guided precise fluorescent laparoscopic hepatocellular carcinoma resection

Background

Applying traditional fluorescence navigation technologies in hepatocellular carcinoma is severely restricted by high false-positive rates, variable tumor differentiation, and unstable fluorescence performance.

Results

In this study, a green, economical and safe nanomedicine formulation technology was developed to construct carrier-free indocyanine green nanoparticles (nanoICG) with a small uniform size and better fluorescent properties without any molecular structure changes compared to the ICG molecule. Subsequently, nanoICG dispersed into lipiodol via a super-stable homogeneous intermixed formulation technology (SHIFT&nanoICG) for transhepatic arterial embolization combined with fluorescent laparoscopic hepatectomy to eliminate the existing shortcomings. A 52-year-old liver cancer patient was recruited for the clinical trial of SHIFT&nanoICG. We demonstrate that SHIFT&nanoICG could accurately identify and mark the lesion with excellent stability, embolism, optical imaging performance, and higher tumor-to-normal tissue ratio, especially in the detection of the microsatellite lesions (0.4 × 0.3 cm), which could not be detected by preoperative imaging, to realize a complete resection of hepatocellular carcinoma under fluorescence laparoscopy in a shorter period (within 2 h) and with less intraoperative blood loss (50 mL).

Conclusions

This simple and effective strategy integrates the diagnosis and treatment of hepatocellular carcinoma, and thus, it has great potential in various clinical applications.

Supplementary information

The online version contains supplementary material available at 10.1186/s12951-022-01467-w.

Molecular fluorescent probes for liver tumor imaging

Liver cancer is a malignant tumor with both high morbidity and mortality. Traditional treatment method is mainly based on hepatectomy for liver tumor. However, it is difficult to accurately distinguish the tumor tissue and its boundary with the naked eye and palpation, leading to an ambiguous resection result, finally causes high recurrence of liver cancer. Molecular fluorescent probes possess lots of advantages, such as non-invasive, high sensitivity, and real-time imaging have been extensively studied in liver cancer imaging and therapy. In this minireview, we briefly introduce the recent developments of always on and activatable fluorescent probes in the liver cancer image and therapy. Future potential challenges of the fluorescent probes for liver tumor are also discussed. We expect that this minireview would improve the fluorescent probes development for real clinical application of liver cancer disease.

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.

Hepatocellular carcinoma in Hepatitis B and Human Immunodeficiency Virus coinfection in Africa: a focus on surveillance

Human immunodeficiency virus (HIV) and hepatitis-B virus (HBV) infections are weighty public health challenges, especially in the African continent. The direct carcinogenic effect of HBV means that it remains a potent cause of early-onset hepatocellular carcinoma (HCC) in Sub-Saharan Africa (SSA), where it causes significant morbidity and mortality. The presence of HIV infection in HBV-infected patients poses a complicating factor, as coinfection has been shown to hasten the progression of liver disease to cirrhosis and HCC, and often resulting in early-age hepatocarcinogenesis with consequent late diagnosis and lower survival. In this review, we discuss this unique conundrum, the epidemiology of HIV-HBV coinfection in SSA, its effect on liver disease and development of HCC, as well as practices and barriers to HCC surveillance in this distinct population. We propose a way forward to curb this considerable health burden focusing on reduction of disease stigma, the need for easy-to-measure biomarkers, and implementation of large prospective studies in this population.

Recent advancements in peripheral nerve-specific fluorescent compounds

Nerve injury is a common complication of surgery. Accidental nerve damage or transection can lead to severe clinical symptoms including pain, numbness, paralysis and even expiratory dyspnoea. In recent years, with the rise of the field of fluorescence-guided surgery, researchers have discovered that nerve-specific fluorescent agents can serve as nerve markers in animals and can be used to guide surgical procedures and reduce the incidence of intraoperative nerve damage. Currently, researchers have begun to focus on biochemistry, materials chemistry and other fields to produce more neuro-specific fluorescent agents with physiological relevance and they are expected to have clinical applications. This review discusses the agents with potential to be used in fluorescence-guided nerve imaging during surgery.

Fluorescence imaging in the surgical management of liver cancers: Current status and future perspectives

Over the last decades, imaging technologies have got significant developments and become indispensable in the surgical management of liver cancers. Real-time navigation afforded by intraoperative images has a significant impact on the success of liver surgeries. Fluorescence imaging in the near-infrared spectrum has shown potential for tumor detection and image-guided surgery in clinics. While predominantly focused on indocyanine green (ICG) imaging, there is also accelerated development of more specific molecular tracers. Compared to passive targeting contrast agents ICG, active targeting and activatable probes both shed new light for intraoperative navigation owing to the higher degree of specificity for the tumor target. A variety of fluorescence imaging probes have been developed to target biomarkers unique to cancer cells or tumor microenvironment and demonstrated promising results. In this review, we provide a comprehensive update on preclinical development and clinical applications of fluorescence imaging in the surgical management of liver cancers. By highlighting the current status, we aim to offer insight into the challenges and opportunities for further investigation.