Near-Infrared Fluorescence Imaging and Photodynamic Therapy for Liver Tumors.

Surgery with fluorescence equipment has improved to treat the malignant viscera, including hepatobiliary and pancreatic neoplasms. In both open and minimally invasive surgeries, optical imaging using near-infrared (NIR) fluorescence is used to assess anatomy and function in real time. Here, we review a variety of publications related to clinical applications of NIR fluorescence imaging in liver surgery. We have developed a novel nanoparticle (indocyanine green lactosome) that is biocompatible and can be used for imaging cancer tissues and also as a drug delivery system. To date, stable particles are formed in blood and have an ~10-20 h half-life. Particles labeled with a NIR fluorescent agent have been applied to cancer tissues by the enhanced permeability and retention effect in animals. Furthermore, this article reviews recent developments in photodynamic therapy with NIR fluorescence imaging, which may contribute and accelerate the innovative treatments for liver tumors.

Near-infrared fluorescence imaging and photodynamic therapy with indocyanine green lactosomes has antineoplastic effects for gallbladder cancer.

BACKGROUND: The diagnostic use and therapeutic effect of near infrared fluorescence (NIF) imaging and photodynamic therapy (PDT) was investigated for gallbladder cancer using indocyanine green (ICG)-lactosomes. RESULTS: PDT was toxic for NOZ cells treated with ICG-lactosomes. Fluorescence intensity in the tumor region of mice administered ICG-lactosomes, but not ICG alone, was higher than the healthy contralateral region ≥24 hours after injection. PDT exerted immediate and continuous phototoxic effects in NOZ implanted mice injected with ICG-lactosomes. Enhanced antitumor effects were observed in the twice irradiated group compared with the once irradiated group. METHOD: ICG or ICG-lactosomes were added to the human gallbladder cancer cell line NOZ followed by PDT and cell viability was measured. Mass spectrometry of ICG and ICG-lactosomes was performed after PDT. ICG or ICG-lactosomes were intravenously administered to BALB/c nude mice implanted subcutaneously with NOZ cells and fluorescence was evaluated by NIF imaging. Implanted tumors underwent PDT and antitumor effects were analyzed after performing irradiation once or twice in ICG-lactosome groups. CONCLUSIONS: ICG-lactosomes accumulated in xenograft tumors and PDT had an antitumor effect on these malignant tumors. NIF imaging with ICG-lactosomes and PDT may be useful diagnostic and/or therapeutic agents for gallbladder cancer.

Near-infrared fluorescence imaging and photodynamic therapy with indocyanine green lactosome has antineoplastic effects for hepatocellular carcinoma.

BACKGROUND: Anticancer agents and operating procedures have been developed for hepatocellular carcinoma (HCC) patients, but their prognosis remains poor. It is necessary to develop novel diagnostic and therapeutic strategies for HCC to improve its prognosis. Lactosome is a core-shell-type polymeric micelle, and enclosing labeling or anticancer agents into this micelle enables drug delivery. In this study, we investigated the diagnostic and therapeutic efficacies of indocyanine green (ICG)-loaded lactosome for near-infrared fluorescence (NIF) imaging and photodynamic therapy (PDT) for HCC. METHODS: The human HCC cell line HuH-7 was treated with ICG or ICG-lactosome, followed by PDT, and the cell viabilities were measured (in vitro PDT efficiency). For NIF imaging, HuH-7 cells were subcutaneously transplanted into BALB/c nude mice, followed by intravenous administration of ICG or ICG-lactosome. The transplanted animals were treated with PDT, and the antineoplastic effects were analyzed (in vivo PDT efficiency). RESULTS: PDT had toxic effects on HuH-7 cells treated with ICG-lactosome, but not ICG alone. NIF imaging revealed that the fluorescence of tumor areas in ICG-lactosome-treated animals was higher than that of contralateral regions at 24 h after injection and thereafter. PDT exerted immediate and continuous phototoxic effects in the transplanted mice treated with ICG-lactosome. CONCLUSIONS: Our results demonstrate that ICG-lactosome accumulated in xenograft tumors, and that PDT had antineoplastic effects on these malignant implants. NIF imaging and PDT with ICG-lactosome could be useful diagnostic and/or therapeutic strategies for HCC.

Genipin Inhibits the Induction of Inducible Nitric Oxide Synthase Through the Inhibition of NF-κB Activation in Rat Hepatocytes.

BACKGROUND/AIMS: Genipin is a component of Japanese traditional herbal medicine (Kampo), inchinkoto, and is used for the treatment of various liver injuries. However, there are few scientific evidence for its anti-inflammatory effects and mechanisms. In inflamed liver, proinflammatory cytokines including tumor necrosis factor (TNF)-α and interleukin (IL)-1ß stimulate liver cells, followed by the expression of inducible nitric oxide synthase (iNOS). Excessive levels of NO produced by iNOS have been implicated as one of the factors in liver injury. Thus it is essential to inhibit iNOS induction for the prevention of liver injury. In this study, we examined IL-1ß-stimulated hepatocytes as a simple "in vitro liver injury model" to investigate liver protective effects of genipin. METHODS: Primary cultured rat hepatocytes were treated with IL-1ß in the presence or absence of genipin. The induction of NO production and iNOS, and its signaling pathway were analyzed. RESULTS: In IL-1ß-stimulated hepatocytes, genipin inhibited the production of NO dose- and timedependently, and reduced the levels of iNOS protein and its mRNA expression. Genipin also reduced mRNA expressions of TNF-α and IL-6. Genipin inhibited two essential signaling pathways for iNOS induction, IκB degradation/NF-κB activation and type I IL-1 receptor upregulation. Transfection experiments revealed that genipin decreased the expression of iNOS mRNA through both inhibitions of the promoter activation and mRNA stabilization. Delayed administration of genipin after IL-1ß addition also inhibited iNOS induction. CONCLUSION: Genipin influenced the induction of inflammatory mediators, iNOS and TNF-α, in part through the inhibition of NF-κB activation in hepatocytes. Genipin may have therapeutic potential for organ injuries including liver.

Evaluation of fluorescence imaging with indocyanine green in hepatocellular carcinoma.

BACKGROUND: We hypothesized that indocyanine green (ICG) fluorescence patterns using Clairvivo OPT in resected liver specimens could confirm hepatocellular carcinoma (HCC) better than earlier commercial imaging systems. This preclinical trial evaluated the effectiveness of fluorescence imaging as an intraoperative cancer navigation tool. METHODS: ICG fluorescence images of resected specimens from 190 patients with HCC were classified into two groups according to whether high fluorescence was seen in the HCC (high cancerous [HC] group) or in the surrounding liver tissue (high surrounding [HS] group). The HC and HS groups were sub-classified into whole and partial types and whole and ring types, respectively. RESULTS: The HC group had significantly higher prevalence of esophageal or gastric varices, and worse liver function than patients in the HS group. The HC group also had a higher percentage of limited resection cases than did the HS group. Cirrhotic liver histology was significantly more common in the HC group than in the HS group. Multivariate analysis revealed that the HC group was a predictive factor for cirrhosis in HCC patients. Among the HC patients, a higher percentage of well-differentiated HCC cases were seen in the partial-type subgroup than in the whole-type subgroup (23/48 (48 %) vs. 7/68 (10 %)). In the HS group, the ring-type subgroup had a higher percentage of poorly differentiated HCC cases than did the whole-type subgroup (6/37 (16 %) vs. 0/37 (0 %)). CONCLUSION: Tumor differentiation and fibrosis in the non-cancerous liver parenchyma could affect ICG fluorescence imaging in HCC. ICG fluorescence imaging may be a good indication for fibrosis stage. In future, we will try to evaluate fluorescence imaging with ICG for intraoperative cancer navigation in HCC, using a portable near-infrared fluorescence imaging system.

Computer-aided liver surgical planning system using CT volumes.

In this paper, we presented our newly developed computer-aided liver surgical planning system for patient-specific treatments by using the patient's CT volumes. The system is composed of three modules, liver segmentation, vessel extraction, and visualization & interaction modules. It can prepare a virtual environment for patient-specific liver surgical planning and simulations. We also developed an original visualization library, which is based on GPU (graphics processing unit) computing for real-time interaction and visualization. The effectiveness of our system was evaluated by surgeons with liver surgery simulations.

Novel liver visualization and surgical simulation system.

BACKGROUND: Successful liver surgery requires an understanding of the patient's particular liver characteristics, including shape and vessel distribution. In clinical medicine, there is a high demand for surgical assistance systems to assess individual patients. Our aims in this study were to segment the liver based on computed tomography volume data and to develop surgical plans for individual patients. METHODS: The hepatic vessels were semi-automatically extracted from the segmented liver images, and the 3D shape of the liver and extracted vessel distribution were visualized using a surgical simulation system. RESULTS: The 3D visualization of the liver allowed easy recognition of vessel and tumor location and selection of these structures with the 3D pointing device. The surgeon's prior knowledge and clinical experience were integrated into the visualization system to create a practical virtual surgery, leading to improved functionality and accuracy of information recognition in the surgical simulation system. CONCLUSIONS: The 3D visualization demonstrated details of individual liver structure, resulting in better understanding and practical surgical simulation.

[Clinical applications of indocyanine green-fluorescent imaging to liver surgery].

BACKGROUND: Intravenous injection of the indocyanine green (ICG) reagent was performed as a liver function test 1 to 2 weeks prior to surgery. ICG fluorescent imaging was performed using the Photodynamic Eye (PDE) infrared camera (Hamamatsu Photonics k. k., Shizuoka, Japan). METHODS: Intravenous injection of the ICG reagent was performed as a liver function test 1 to 2 weeks before surgery. ICG fluorescent imaging was performed using the PDE infrared camera. RESULTS: ICG fluorescent imaging was useful for liver surgical navigation as follows: three cases of recurrent hepatocellular carcinoma(HCC) after transcatheter arterial chemoembolization or thermal ablation therapy; three cases of colorectal metastatic liver tumors after chemotherapy as conversion therapy; two cases of intrahepatic cholangiocellular carcinoma (ICC); and two cases of surface HCC that were not detected by preoperative computed tomography (CT) scan. In the ICC cases, although dilatation of the bile duct could be detected, the tumor margins were ambiguous by ultrasonography(US). ICG fluorescent imaging clearly described the dilatation of the bile duct including the tumor. CONCLUSIONS: ICG fluorescent imaging was useful for liver surgical navigation including selection of the mode of hepatic resection.

[Hepatectomy for liver metastasis in malignant melanoma of ocular choroid origin-a case report].

A 55-year-old man who underwent eye enucleation at our hospital's ophthalmology department was pathologically diagnosed with malignant melanoma. Four months later after diagnosis, he underwent positron emission tomography/computed tomography for detecting systemic metastasis. Abnormal accumulation was found in S4 of the liver. He was therefore referred to the gastrointestinal department, where liver metastasis from malignant melanoma was diagnosed by biopsy. He underwent radiofrequency ablation therapy. A recurrence 3 months later was judged difficult to manage medically. He was thus sent to our department. Preoperative magnetic resonance imaging revealed multiple tumors in both liver lobes. Thus far, no treatment strategy has been established for hepatic metastases of malignant melanoma. After receiving a thorough explanation, he agreed to partial hepatectomy. We identified 14 tumors by intraoperative ultrasonography as sites for partial hepatectomy. Postoperative chemotherapy was administered. He died of hepatic failure 9 months after the operation. It is necessary to accumulate further cases on a national scale, because establishment of appropriate therapy for this condition is urgently needed.

[A case of a colon cancer patient with liver metastasis subjected to hepatectomy after achieving radiographic complete response with preoperative chemotherapy].

In 2006, a 70-year-old man who underwent low anterior resection for rectal cancer (SS, N0, H1, Stage IV)at a nearby hospital was referred to our hospital. He was noted to have multiple liver metastases of approximately 1 cm in diameter in S2, S3, S6, and S7, and was subsequently treated with chemotherapy for 5 courses of mFOLFOX6 regimen. He achieved a complete response radiographically. Thereafter, he underwent lateral segmentectomy of the liver and was noted to have residual tumor cells by histopathological examination of the resected tissue. Seven months after the hepatectomy, recurrence occurred in S6 and S7 and a new lesion in S8 was noted. He then underwent 12 courses of mFOLFOX6. As of June 2012, the patient is alive without recurrence. A prolonged survival may be possible if downstaging is achieved with successful chemotherapy. However, similar to the present case, the detection of residual cancer cells during histopathological examination of the resected tissues has been reported in the literature. Thus, further investigation is needed to determine the optimal treatment of cases achieving a radiographic complete response.