Infrared Fluorescence Endoscopy Research Articles

Laparoscopic fluorescence image-guided photothermal therapy enhances cancer diagnosis and treatment.

Endoscopy is the gold standard investigation in the diagnosis of gastrointestinal cancers and the management of early and pre-malignant lesions either by resection or ablation. Recently gold nanoparticles have shown promise in cancer diagnosis and therapeutics (theranostics). The combination of multifunctional gold nanoparticles with near infrared fluorescence endoscopy for accurate mapping of early or pre-malignant lesions can potentially enhance diagnostic efficiency while precisely directing endoscopic near infrared photothermal therapy for established cancers. The integration of endoscopy with near infrared fluorescence imaging and photothermal therapy was aided by the accumulation of our multifunctionalized PEG-GNR-Cy5.5-anti-EGFR-antibody gold nanorods within gastrointestinal tumor xenografts in BALB/c mice. Control mice (with tumors) received either gold nanorods or photothermal therapy, while study mice received both treatment modalities. Local (tumor-centric) and systemic effects were examined for 30 days. Clear endoscopic near infrared fluorescence signals were observed emanating specifically from tumor sites and these corresponded precisely to the tumor margins. Endoscopic fluorescence-guided near infrared photothermal therapy successfully induced tumor ablations in all 20 mice studied, with complete histological clearance and minimal collateral damage. Multi-source analysis from histology, electron microscopy, mass spectrometry, blood, clinical evaluation, psychosocial and weight monitoring demonstrated the inherent safety of this technology. The combination of this innovative nanotechnology with gold standard clinical practice will be of value in enhancing the early optical detection of gastrointestinal cancers and a useful adjunct for its therapy.

Towards an ASIC-based Fluoroscopic Capsule for the Early Cancer Detection in the Small Intestine.

Early micro-cancer detection in the small intestine can be realized using infrared fluorescence endoscopy (IRFE) in conjunction with an infrared fluorescence biomarker. In this paper, we present a third-generation capsule that detects weak fluorescence signals emitted by low concentrations of indocyanine green (ICG). An applicationspecific integrated circuit (ASIC) has been designed and fabricated that integrates many of the peripheral components of the capsule system. The ASIC enables the system to have greater sensitivity whilst reducing the capsule size and lowering the power consumption.

Infrared Fluorescence-Based Cancer Screening Capsule for the Small Intestine.

Infrared fluorescence endoscopy (IRFE), in conjunction with an infrared fluorescent-labelling contrast agent, is a well known technique used for efficient early-stage cancer detection. In this paper we present a cost-effective (< $500) screening capsule prototype, which is able to detect infrared (IR) fluorescence emitted by indocyanine green (ICG) fluorophore dye. Rather than image, the capsule works as a high-sensitivity fluorometer that records fluorescence levels throughout the small intestine. The presented mixed-signal system has a small size, consumes very little power (≈ 6.3 mA) and does not require an external belt and hardware for data collection. By determining fluorescence levels in the intestine, rather than collecting images, we avoid the need for labour intensive video analysis. The whole system is contained within a compact ingestible capsule, that is sized so as to come into close contact with the intestine walls during peristalsis. Ex-vivo experiments, on ICG-impregnated swine intestine, have shown that the prototype system is able to detect low concentrations of ICG in the nanomolar and micromolar region, which is required to detect early cancer in the small intestine.

Towards a fluoroscopic cancer screening capsule for the small intestine.

Efficient microcancer detection in the small intestine can be realised by infrared fluorescence endoscopy (IRFE). The affected areas can be visualised through that technique in conjunction with an infrared fluorescent-labeling contrast agent, which is selectively uptaken by cancerous cells. In this paper we present a screening capsule prototype that is able to measure IR fluorescence levels emitted by fluorophore indocyanine green (ICG) of different concentrations. The mixed-signal system presented has small area footprint, and very little power requirements. In-vitro experiments have shown that the system is able to detect and discriminate low concentrations of ICG in the micromolar region, which is required to detect early cancer in the small intestine.

Infrared endoscopy in the diagnosis and treatment of early gastric cancer

Infrared endoscopy combined with indocyanine green injection allows visualization of the vessels in the gastrointestinal tract. The depth of gastric cancer invasion has been diagnosed through evaluation of the submucosal vessels using this method. Small-scale retrospective studies have reported an accuracy for infrared endoscopy of > 80 % for the diagnosis of the depth of cancer invasion, regardless of ulcerative changes. This endoscopic technique should thus be considered as an additional diagnostic modality for determining the depth of gastric cancer, particularly in cases with ulcerative changes. However, the risk of a toxic reaction to indocyanine green must be addressed before the widespread use of infrared endoscopy can be implemented. Infrared fluorescence endoscopy utilizes the fluorescence of indocyanine green, and has been used not only for diagnosing the depth of gastric cancer invasion, but also for detecting neoplasia. Labeling and visualization of cancer in a resected specimen were possible following pre-treatment with anti-carcinoembryonic antigen antibody labeled with an indocyanine green derivative. A critical requirement for the detection of cancer using infrared fluorescence endoscopy is the identification of a safe labeling substance that attaches to the cancer with high affinity. It was possible to detect sites of bleeding during endoscopic resection of gastric cancers by submucosal injection or flushing of the bleeding site with indocyanine green solution. The dose of indocyanine green required by these methods is relatively low, and they can therefore be used to improve the safety of endoscopic resection with no increased risk of toxicity.

Labeled anti-mucin antibody detectable by infrared-fluorescence endoscopy

The goal of our study was to develop a method for molecular imaging of the gastrointestinal tract using an infrared fluorescence endoscope (IRFE) and antibodies labeled with an indocyanine green (ICG) derivative to detect cancerous tissue. The IRFE comprised an infrared endoscope equipped with excitation (710-790 nm) and barrier (810-920 nm) filters. We developed ICG-N-hydroxysulfosuccinimide ester (ICG-sulfo-OSu) and 3-ICG-acyl-1,3-thiazolidine-2-thione (ICG-ATT) as infrared fluorescent-labeling reagents, and anti-human carcinoembryonic antigen (CEA) antibody and MUC1 antibody were labeled with the ICG-derivatives. Freshly resected specimens of gastric cancer were observed by IRFE after reaction with ICG-derivative-labeled antibodies. Positive fluorescence was observed at the tumor location by IRFE, and the immunofluorescent images correlated well with the tumor sites. The immunofluorescence studies suggested that the intensity of the infrared fluorescence of the ICG-ATT-labeled MUC1 antibody is stronger than the ICG-sulfo-OSu-labeled MUC1 antibody. We concluded that specific antibodies for gastrointestinal cancer labeled with an ICG-derivative accompanied by a reinforcing agent and an optimal electronic device can generate a strong enough fluorescent signal to visualize cancer proteins.

Infrared Fluorescence Endoscopy Combined with Indocyanine Green Injection for Evaluation of Severity in Patients with Ulcerative Colitis

Infrared Fluorescence Endoscopy Combined with Indocyanine Green Injection for Evaluation of Severity in Patients with Ulcerative Colitis

Infrared fluorescence endoscopy for the diagnosis of superficial gastric tumors

Indocyanine green (ICG) is a fluorescent marker that is excited by rays at a wavelength of 768 nm to emit fluorescence at a wavelength of 807 nm in the infrared (IR) range. We developed an IR fluorescence endoscope (IRFE) to observe superficial gastric tumors and assessed its clinical usefulness. To evaluate the clinical usefulness of an IRFE for the assessment of superficial gastric tumors. An observational study. University hospital. Newly developed IRFE. Thirty patients with gastric tumors were enrolled in this study, and their lesions were subjected to endoscopic submucosal dissection (ESD), or laparoscopic gastrectomy after observation with the IRFE. Gastric lesions were subjected to conventional observation, followed by IR fluorescence observation before and after intravenous ICG (0.01 mg/kg) injection. The relationship between the positive fluorescence and invasivity of each tumor. Fluorescence was positive in 8 of 10 gastric cancers with submucosal invasion (80%) and 1 of 20 adenomas or intramucosal gastric cancers (5%); the difference was statistically significant (P<.01). IRFE is a useful diagnostic tool for estimating the invasivity of gastric tumors.

Usefulness of Infrared Fluorescence Endoscopy for the Diagnosis of Superficial Gastric Tumors

Usefulness of Infrared Fluorescence Endoscopy for the Diagnosis of Superficial Gastric Tumors

Principle and clinical usefulness of the infrared fluorescence endosscopy

Since there is no infrared fluorescence materials in the living body, infrared fluorescence labeling materials are very useful for making a diagnosis of a micro cancer. We have developed an infrared fluorescence endoscope (IRFE) and indocyanin green (ICG)-derivative as infrared fluorescence labeling materials to evaluate gastrointestinal neoplastic lesions. The study aims were to apply an IRFE and to demonstrate its usefulness in detecting cancerous tissue using an antibody coupled with ICG-derivative. IRFE consisted of an infrared endoscope equipped with excitation (710-790 nm) and barrier (810-920 nm) filters and an intensified CCD camera. We have developed ICG N-hydroxy sulfo succinimide ester (ICG-sulfo-OSu) and 3-ICG-acyl-1, 3-thiazolidine-2-thione (ICG-ATT) as an infrared fluorescent-labeling reagent. ICG-derivative-labeled mouse anti-human carcinoembryonic antigen (CEA) antibody and MUC1 antibody were employed in this study. Moreover, we examined the ability of a reinforcement agent, octylglucoside, to intensity fluorescence from the labeled antibody. Biopsy specimens of gastric cancer were stained with anti-CEA antibody by the avidin-biotinylated peroxidase complex method. Among the positive specimens, freshly resected stomach from three cases were used for the infrared (IR) imaging analysis. The incubation of freshly resected stomach specimens with ICG-anti-CEA antibody-complex resulted in positive staining of the tumor sites by IRFE, and the IR fluorescent images correlated well with the tumor sites. The immunohistochemical studies suggested that the intensity of IR fluorescence of ICG-ATT-MUC1 was stronger than that of ICG-sulfo-OSu. In tumor sections, the reinforcement agent intensified fluorescence, ever at low antibody concentrations. Therefore, we conclude that an anti-CEA (and/or MUC1) antibody with affinity for cancerous lesions and labeled with ICG-derivative can be imaged with this IRFE. Specific antibodies tagged with ICG-derivative with the reinforcement agent can label cancer cells and generate a strong enough fluorescent signal to detect small cancers when examined with an IR fluorescence endoscope.

A Novel Diagnostic Method for Evaluation of Vascular Lesions in the Digestive Tract Using Infrared Fluorescence Endoscopy

We have developed an infrared fluorescence endoscope to evaluate gastrointestinal vascular lesions. Infrared endoscopy (IRE) after intravenous administration of indocyanine green (ICG) is used at present to examine vascular lesions such as esophageal varices. However, no previous study has compared the sensitivity of infrared fluorescence endoscopy (IRFE) with that of IRE. In this study, we compared the usefulness of IRFE and IRE. For IRFE we used an infrared endoscope equipped with excitation and barrier filters and an intensified charge-coupled device camera. In preliminary experiments, the observable tissue depth was assessed by wrapping increasing numbers of layers of commercially available pork around a syringe containing a uniform concentration of ICG or by changing the concentration of ICG in a syringe covered by a piece of pork of uniform thickness. In the clinical part of the study, ICG was administered intravenously at different concentrations to patients with esophageal varices and the resulting infrared fluorescent images were evaluated. The preliminary experiments revealed that the depth of tissue that could be visualized was significantly greater in IRFE than it was in IRE (11.2 mm in IRFE vs. approximately 3.2 mm in IRE). Clear infrared fluorescence was obtained by IRFE at lower concentrations of ICG than the concentrations required to obtain clear images using IRE. In the clinical part of the study, clear infrared fluorescence was observed in a region where esophageal varices had been detected by conventional endoscopy when ICG was administered in doses of 0.005 mg/kg to 0.01 mg/kg, which was lower than the doses used in IRE. Compared with conventional IRE, IRFE facilitated the observation of deeper layers, and esophageal varices were observed by IRFE following the intravenous administration of a markedly reduced dose of ICG. IRFE, in combining the characteristics of reflected infrared light and fluorescence, may be a useful novel procedure in the diagnosis of vascular lesions in the gastrointestinal tract.

Basic study of an agent for reinforcement of near-infrared fluorescence on tumor tissue

Background and aims. An indocyanine green derivative (ICG-sulfo–OSu) and agents for reinforcement of infrared fluorescence, which can be used as an infrared fluorescent labeling substance suitable for detection of microlesions by an IR fluorescence endoscope, have been developed. The study aims were to confirm the ability of a reinforcement agent, as well as imaging processing, to intensify fluorescence from the labeled antibody on immunohistochemical staining. Subjects and methods. ICG-sulfo–OSu-labeled MUC1 antibody and an IR fluorescence imaging system were employed in the present study. Paraffin sections of gastric cancer were stained with anti-MUC1 antibody by the avidin–biotinylated peroxidase complex method. Among the positive specimens, three cases were used for IR imaging analysis. Octylglucoside was used as a reinforcement agent. Results. The incubation of paraffin sections with ICG-sulfo–OSu-labeled MUC1 antibody resulted in positive staining of the tumor sites by an IR fluorescence imaging system, and the intensity of fluorescence was increased depending on the concentration of octylglucoside and grade of imaging processing. Conclusion. A reinforcement agent, and image processing, intensify a labeled antibody excitable by infrared fluorescence in tumor sections and can generate a strong enough fluorescent signal to detect small cancers when examined with an infrared fluorescence endoscope.

513 赤外線蛍光内視鏡を用いた消化管微小癌診断法の開発

513 赤外線蛍光内視鏡を用いた消化管微小癌診断法の開発

What can we see with the endoscope? Present status and future perspectives

The present status and future perspectives in new technologies of image processing and analysis, infrared ray endoscopy and autofluorescence endoscopy for gastrointestinal cancer are presented in this paper. Spectroscopic measurements using an endoscopic spectroscopic system are useful for distinguishing between benign and malignant gastric mucosal lesions, and the histological classification of early gastric cancer is possible on the basis of the spectroscopic characteristics. It is expected that adaptive hemoglobin index color enhancement would be useful for the qualitative diagnosis of early gastric cancer and for detecting specialized columnar epithelium in Barrett’s esophagus in combination with magnifying endoscopy. Our preliminary experience suggess that magnifying endoscopy with a narrow‐band imaging system could predict the histological characteristics of gastric cancerous lesions with high accuracy. Recent studies revealed that infrared ray electronic endoscopy is very useful for diagnosing the depth of invasion in early gastric cancer. In addition, it is evident that specific antibodies tagged with the indocyanine green derivative can label cancer cells and can generate a fluorescent signal strong enough to detect small cancers using an infrared fluorescence endoscope. The future development and evaluation of autofluorescence endoscopy are discussed, and we propose a modification to the system, including the excitation lights.

Basic studies on a labeled anti-mucin antibody detectable by infrared-fluorescence endoscopy

We developed a fluorescent dye, indocyanine green (ICG)-sulfo-OSu, which was excited by infrared rays and conjugated to various antibodies. We attempted to clarify the staining patterns of antisulfomucin and anti-MUC1 antibodies in gastrointestinal cancer. We then evaluated the potential of the dye as a fluorescent label for antibodies specific to cancer, to be used as a diagnostic method for microcancer, with infrared fluorescence endoscopy. Paraffin sections of samples collected from 10 patients with esophageal cancer, 30 patients with gastric cancer, and 20 patients with colorectal cancer were immunohistologically stained using an anti-sulfomucin antibody and an anti-MUC1 antibody, and the staining patterns were examined. If a section had a high staining intensity, it was reacted with the ICG-suflo-OSu-labeled antibody and evaluated with infrared fluorescence imaging. The staining patterns with the antibodies varied depending on the organs and the histological types and depth of the cancers, but the staining was generally good and the staining on the mucosal surface of cancer tissues was retained. Good images of cancer cells could be obtained by infrared fluorescence observation using the ICG-sulfo-OSu-labeled anti-MUC1 antibody. The anti-MUC1 antibody stained gastrointestinal cancer cells well, and nearly specific infrared fluorescence in cancer tissues was observed using the labeled anti-MUC1 antibody. The ICG-sulfo-OSu-labeled anti-MUC1 antibody has possible usefulness for the screening of cancer via infrared fluorescence endoscopy.

Detection of human gastric cancer in resected specimens using a novel infrared fluorescent anti-human carcinoembryonic antigen antibody with an infrared fluorescence endoscope in vitro.

An indocyanine green derivative (ICG-sulfo-OSu) that can be used as an infrared fluorescent labeling substance suitable for detecting microlesions with an infrared fluorescence endoscope has been developed. The aims of the present study were to develop an infrared fluorescence endoscope and to demonstrate its usefulness in detecting cancerous tissue using an antibody coupled with ICG-sulfo-OSu. ICG-sulfo-OSu-labeled mouse anti-human carcinoembryonic antigen (CEA) antibody and an infrared fluorescence endoscope were used in this study. Biopsy specimens of gastric cancer were stained with anti-CEA antibody using the avidin-biotinylated peroxidase complex method. The positive specimens used for the infrared imaging analysis were freshly resected stomachs from three patients. Treatment of freshly resected stomach specimens with ICG-sulfo-OSu-labeled-anti-CEA antibody complex resulted in positive staining of the tumor sites on infrared fluorescence endoscopy, and the infrared fluorescent images correlated well with the tumor sites. An anti-CEA antibody with affinity for cancerous lesions and labeled with ICG-sulfo-OSu can therefore be imaged using this infrared fluorescence endoscope. Specific antibodies tagged with ICG-sulfo-OSu can label cancer cells and can generate a strong enough fluorescent signal to detect small cancers when examined with an infrared fluorescence endoscope.

Reflected Illumination‐Type Imaging System for the Development of Infrared Fluorescence Endoscopy

Abstract:Fluorescent labeled monoclonal antibodies against carcinoembryonic antigen (CEA) may provide a specific label for lesions of the GI tract. We previously developed an indocyanine green (ICG) derivative (ICG N‐hydroxy sulfo succinimide ester; ICG‐sulfo‐Osu) as a fluorescent label that is excited by infrared rays and is suitable for vital immunohistochemical staining. We also previously developed a transmitted illumination‐type (transmitted type) fluorescence imaging system that uses infrared rays to detect ICG‐sulfo‐Osu. In this paper we describe a new reflected illumination‐type (reflected type) imaging system for infrared fluorescence endoscopy. We tested the efficacy of this system on sections of human esophagus and normal skeletal muscle stained with ICG‐sulfo‐Osu labeled anti‐epithelial membrane antigen (EMA) antibody, and on sections of human gastric cancer tissue stained with ICG‐sulfo‐Osu labeled anti‐CEA antibody. Infrared fluorescent images were obtained with both fluorescent antibodies, and results correlated well with oxidized DAB‐positive sites. Vital immunohistochemical staining of micro cancers should be detectable by exciting an ICG‐sulfo‐Osu labeled antibody specific to the tumor cells with infrared rays, using this reflected type imaging system.