Fluorescence navigation with indocyanine green for detecting sentinel lymph nodes in breast cancer

Lymphaticovenular Anastomosis: Superficial Venous Anatomical Approach

Background  Lymphaticovenular anastomosis (LVA) is an effective, functional treatment for limb lymphedema. This study reports an alternative surgical approach to lymphedema treatment without the use of indocyanine green mapping.

Methods  A retrospective analysis was performed on 29 consecutive lymphedema patients who underwent LVAs from January 2015 to December 2020, whereby incisions were made along the anatomy of the superficial venous systems in both upper and lower extremities around the joint areas. The evaluation included qualitative assessments and quantitative volumetric analyses.

Result  The mean number of anastomoses was 3.07, and the operative time was 159.55 minutes. Symptom improvement was recorded in 86.21% of the patients, with a mean volume reduction of 32.39%. The lymphangitis episodes decreased from 55.17% before surgery to 13.79% after surgery, and the median number of lymphangitis episodes per year decreased from 1 before surgery to 0 after surgery.

Conclusions  The superficial venous anatomical approach is an easy way to start a lymphedema practice using LVA without other advanced surgical equipment. With this reliable technique, microsurgeons can perform LVA procedures and achieve good results.

Optimal settings of near-infrared fluorescence imaging with indocyanine green for intraoperative detection of lymph node metastasis in esophageal cancer

Lymphatic flow mapping using near-infrared fluorescence (NIR) imaging with indocyanine green (ICG) has been used for intraoperative diagnosis of lymph node metastasis (LNM) in various cancers. Accurate prediction of LNM intraoperatively may allow minimization of the extent of lymphadenectomy. However, a consistent method and diagnostic ability, allowing application of NIR-guided lymphatic flow mapping to esophageal cancer (EC), have not been established due to the multidirectional and complex characteristics of lymphatic flow in the esophagus. Herein, we present a novel NIR-guided surgical technique for predicting lymph node stations potentially containing LNM in EC with high diagnostic accuracy derived from appropriately adjusting the ICG injection setting.

Short-term and long-term outcomes of indocyanine green for sentinel lymph node biopsy in early-stage breast cancer

Background

Indocyanine green (ICG) is becoming a frequently used sentinel lymph node (SLN) tracer of breast cancer in China. However, there is still a lack of data on its safety. We reported the clinical outcome of ICG as a tracer of SLN over a median 67-month follow-up period to evaluate its feasibility in clinically node-negative patients with breast cancer.

Methods

A total of 194 consecutive patients underwent sentinel lymph node biopsy (SLNB) with ICG, radioisotopes (RI) and methylene blue (MB), or with ICG and MB. The SLN mapping data by each tracer was recorded, and safety outcomes were analyzed through follow-up.

Results

With the triad mapping (N = 44), the identification rate of SLN by ICG was 95.5%, slightly higher than that of MB (86.4%) and comparable with RI (95.5%) and combined methods (95.5%, 100%) (p = 0.068). Analysis of all candidates (N = 194) demonstrated that the identification rate of SLN by ICG or by ICG and MB was 99%, significantly higher than that by MB (92.8%) (p < 0.0001). No tracer-related allergic reaction and permanent skin staining of ICG were observed. Local disease progression was reported in 2 of the 194 patients at the ipsilateral axilla. After remedial axillary lymph node dissection, no disease progression was detected at follow-up.

Conclusions

ICG as an SLN tracer is more accurate than MB and comparable to the combined methods and has good clinical safety. ICG can be considered a useful supplement or suitable alternative to traditional tracers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02719-7.

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.

Development of Intraoperative Near-Infrared Fluorescence Imaging System Using a Dual-CMOS Single Camera

We developed a single-camera-based near-infrared (NIR) fluorescence imaging device using indocyanine green (ICG) NIR fluorescence contrast agents for image-induced surgery. In general, a fluorescent imaging system that simultaneously provides color and NIR images uses two cameras, which is disadvantageous because it increases the imaging head of the system. Recently, a single-camera-based NIR optical imaging device with quantum efficiency partially extended to the NIR region was developed to overcome this drawback. The system used RGB_NIR filters for camera sensors to provide color and NIR images simultaneously; however, the sensitivity and resolution of the infrared images are reduced by 1/4, and the exposure time and gain cannot be set individually when acquiring color and NIR images. Thus, to overcome these shortcomings, this study developed a compact fluorescent imaging system that uses a single camera with two complementary metal-oxide semiconductor (CMOS) image sensors. Sensitivity and signal-to-background ratio were measured according to the concentrations of ICG solution, exposure time, and camera gain to evaluate the performance of the imaging system. Consequently, the clinical applicability of the system was confirmed through the toxicity analysis of the light source and in vivo testing.

Fluorescent Tracers for In Vivo Imaging of Lymphatic Targets

The lymphatic system continues to gain importance in a range of conditions, and therefore, imaging of lymphatic vessels is becoming more widespread for research, diagnosis, and treatment. Fluorescent lymphatic imaging offers advantages over other methods in that it is affordable, has higher resolution, and does not require radiation exposure. However, because the lymphatic system is a one-way drainage system, the successful delivery of fluorescent tracers to lymphatic vessels represents a unique challenge. Each fluorescent tracer used for lymphatic imaging has distinct characteristics, including size, shape, charge, weight, conjugates, excitation/emission wavelength, stability, and quantum yield. These characteristics in combination with the properties of the target tissue affect the uptake of the dye into lymphatic vessels and the fluorescence quality. Here, we review the characteristics of visible wavelength and near-infrared fluorescent tracers used for in vivo lymphatic imaging and describe the various techniques used to specifically target them to lymphatic vessels for high-quality lymphatic imaging in both clinical and pre-clinical applications. We also discuss potential areas of future research to improve the lymphatic fluorescent tracer design.

Efficacy and Safety of Mitoxantrone Hydrochloride Injection for Tracing Axillary Sentinel Nodes in Breast Cancer: A Self-Controlled Clinical Trial

Background

Mitoxantrone hydrochloride injection for tracing (MHI), a new strategy to identify lymph nodes, has not been tested for axillary node staging in breast cancer. This multicenter, self-controlled, non-inferiority trial aimed to evaluate MHI’s efficacy and safety in sentinel lymph node biopsy (SLNB).

Methods

The trial was conducted across seven hospitals from December 2019 to December 2020. Patients with early-stage breast cancer received MHI and technetium-99m (99mTc) during the surgery. Sentinel node detection rates were compared between MHI and 99mTc to evaluate non-inferiority and concordance. Non-inferiority was valid if the lower limit of the 95% CI of sentinel node relative detection rate difference was ≥−5%.

Results

SLN relative detection rate of MHI was 97.31% (362/372). Of the SLNs, 79.69% (871/1093) were co-detected by both tracers. Of the patients, 4.13% (16/387) had adverse events and recovered during the follow-up.

Conclusions

MHI is a lymphatic tracer with comparable efficacy to radionuclides and can be used alone or in combination with radioactive substances for SLNB.

Clinical Trial Registration

http://www.chinadrugtrials.org.cn, CTR20192435.

Mouthwash as a non-invasive method of indocyanine green delivery for near-infrared fluorescence dental imaging

SIGNIFICANCE

X-ray imaging serves as the mainstream imaging in dentistry, but it involves risk of ionizing radiation.

AIM

This study presents the feasibility of indocyanine green-assisted near-infrared fluorescence (ICG-NIRF) dental imaging with 785-nm NIR laser in the first (ICG-NIRF-I: 700 to 1000 nm) and second (ICG-NIRF-II: 1000 to 1700 nm) NIR wavelengths.

APPROACH

Sprague Dawley rats with different postnatal days were used as animal models. ICG, as a fluorescence agent, was delivered to dental structures by subcutaneous injection (SC) and oral administration (OA).

RESULTS

For SC method, erupted and unerupted molars could be observed from ICG-NIRF images at a short imaging time (<1  min). ICG-NIRF-II could achieve a better image contrast in unerupted molars at 24 h after ICG injection. The OA could serve as a non-invasive method for ICG delivery; it could also cause the glow-in-dark effect in unerupted molars. For erupted molars, OA can be considered as mouthwash and exhibits outstanding performance for delivery of ICG dye; erupted molar structures could be observed at a short imaging time (<1  min) and low ICG dose (0.05  mg  /  kg).

CONCLUSIONS

Overall, ICG-NIRF with mouthwash could perform in-vivo dental imaging in two NIR wavelengths at a short time and low ICG dose.

Intraoperative Tumor Identification During Laparoscopic Distal Gastrectomy: a Novel Fluorescent Clip Marking Versus Metal Clip Marking and Intraoperative Gastroscope

BACKGROUND

In complete laparoscopic distal gastrectomy, the gastric resection line is difficult to determine due to a lack of tactile sensation. The use of intraoperative gastroscopy and intraoperative radiography has been reported, but the burden on personnel and technical complexity present impediments. In our department, based on lesion extent determined with preoperative gastroscopy, a fluorescent clip is used to mark the oral side of the lesion, which is resected after confirmation with a fluorescent laparoscopic system. In this study, we investigated the efficacy of fluorescent clip marking (FCM) in achieving an accurate resection line and reducing the operative time.

METHODS

Fifty-six patients with gastric cancer who underwent complete laparoscopic distal gastrectomy from January 2018 to March 2021 were divided into two groups: the FCM group (n = 32) and the conventional metal clip marking and intraoperative gastroscopy (MCMG) group (n = 24). Short-term outcomes, including the resection margins, gastric resection time, and operative time, were compared and examined.

RESULTS

The fluorescent clips were visible in all cases, and all stumps were negative according to permanent preparations. The operative times for FCM and MCMG were 350 (216-533) vs. 373.5 (258-651) min, respectively, with no significant difference (p = 0.316), while the gastric resection times were 636.5 (321-2572) vs. 1457.5 (843-4973) s, respectively, and were significantly shorter in the FCM group (p < 0.0001).

CONCLUSIONS

FCM shortened the gastric resection time and could possibly shorten the operative time. FCM is feasible and safe and can potentially be used as a tumor-marking agent to determine accurate surgical resection lines.

CLINICAL TRIAL REGISTRATION

Examination of Gastric Cancer, Research Ethics Committee of the Kawaguchi Municipal Medical Centre (Saitama, Japan), approval number: 2019-33. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

Near-Infrared Fluorescence Axillary Reverse Mapping (ARM) Procedure in Invasive Breast Cancer: Relationship between Fluorescence Signal in ARM Lymph Nodes and Clinical Outcomes

Simple Summary

Near-infrared fluorescence axillary reverse mapping (ARM) is a promising procedure for identification and preservation of arm lymphatic drainage during axillary lymph node dissection (ALND). We included 109 patients to analyze the indocyanine green fluorescence signal in ARM lymph nodes after resection. The fluorescence signal from ARM lymph nodes were compared with clinical findings to determine the importance of this criterion on the potential management of patients with ALND. ARM lymph nodes were identified in 94.5% of cases. The mean normalized fluorescence signal intensity value was 0.47 with no significant signal difference between metastatic and non-metastatic ARM lymph nodes. Only the preoperative diagnosis of metastasis in the axillary nodes of patients was significantly associated with a higher ARM node fluorescence signal intensity. Although preliminary results did not show that fluorescence signal intensity is a reliable diagnostic tool, the NIR fluorescence ARM procedure may be useful for ARM lymph node identification.

Abstract

The near-infrared (NIR) fluorescence axillary reverse mapping (ARM) procedure is a promising tool to identify and preserve arm lymphatic drainage during axillary lymph node dissection (ALND). The ARMONIC clinical trial was conducted to validate the technique on a large cohort of patients and to analyze the predictive clinical factors for ARM lymph node metastasis. For the first time, the fluorescence signal intensity from the ARM lymph nodes was measured and correlated with clinical findings. A total of 109 patients with invasive breast cancer and indications of mastectomy and ALND underwent the NIR fluorescence ARM procedure. Indocyanine green was administered by intradermal injection followed by intraoperative identification and resection of the ARM lymph nodes with NIR fluorescence camera guidance. The fluorescence signal intensity and signal distribution were then measured ex vivo and compared with clinical outcomes. ARM lymph nodes were successfully identified by fluorescence in 94.5% of cases. The mean normalized fluorescence signal intensity value was 0.47 with no significant signal difference between metastatic and non-metastatic ARM lymph nodes (p = 0.3728). At the microscopic level, the fluorescence signal distribution was focally intense in lymphoid tissue areas. Only the preoperative diagnosis of metastasis in the axillary nodes of patients was significantly associated with a higher ARM node fluorescence signal intensity (p = 0.0253), though it was not significantly associated with the pathological nodal (pN) status (p = 0.8081). Based on an optimal cut-off fluorescence value, the final sensitivity and specificity of the NIR fluorescence ARM procedure for ARM lymph node metastatic involvement were 64.7% and 47.3%, respectively. Although our preliminary results did not show that fluorescence signal intensity is a reliable diagnostic tool, the NIR fluorescence ARM procedure may be useful for ARM lymph node identification. Clinical trial registration: NCT02994225.

Methylene Blue Near-Infrared Fluorescence Imaging in Breast Cancer Sentinel Node Biopsy

INTRODUCTION

Fluorescence-based navigation for breast cancer sentinel node biopsy is a novel method that uses indocyanine green as a fluorophore. However, methylene blue (MB) also has some fluorescent properties. This study is the first in a clinical series presenting the possible use of MB as a fluorescent dye for the identification of sentinel nodes in breast sentinel node biopsy.

MATERIAL AND METHODS

Forty-nine patients with breast cancer who underwent sentinel node biopsy procedures were enrolled in the study. All patients underwent standard simultaneous injection of nanocolloid and MB. We visualized and assessed the sentinel nodes and the lymphatic channels transcutaneously, with and without fluorescence, and calculated the signal-to-background ratio (SBR). We also analyzed the corresponding fluorescence intensity of various dilutions of MB.

RESULTS

In twenty-three patients (46.9%), the location of the sentinel node, or the end of the lymphatic path, was visible transcutaneously. The median SBR for transcutaneous sentinel node location was 1.69 (range 1.66-4.35). Lymphatic channels were visible under fluorescence in 14 patients (28.6%) prior to visualization by the naked eye, with an average SBR of 2.01 (range 1.14-5.6). The sentinel node was visible under fluorescence in 25 patients (51%). The median SBR for sentinel node visualization with MB fluorescence was 2.54 (range 1.34-6.86). Sentinel nodes were visualized faster under fluorescence during sentinel node preparation. Factors associated with the rate of visualization included diabetes (p = 0.001), neoadjuvant chemotherapy (p = 0.003), and multifocality (p = 0.004). The best fluorescence was obtained using 40 μM (0.0128 mg/mL) MB, but we also observed a clinically relevant dilution range between 20 μM (0.0064 mg/mL) and 100 μM (0.032 mg/mL).

CONCLUSIONS

For the first time, we propose the clinical usage of MB as a fluorophore for fluorescence-guided sentinel node biopsy in breast cancer patients. The quenching effect of the dye may be the reason for its poor detection rate. Our analysis of different concentrations of MB suggests a need for a detailed clinical analysis to highlight the practical usefulness of the dye.

Pathologic correlation with near infrared-indocyanine green guided surgery for pediatric liver cancer

PURPOSE

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common primary malignant tumors of childhood. Intraoperative indocyanine green (ICG) administration with near-infrared imaging (NIR) has emerged as a surgical technology that can be used to assist with localization of pulmonary metastases secondary to HB; however, there has been limited application as an adjunct for resection of the primary liver tumor and assessment of extrahepatic disease.

METHODS

We present 14 patients treated for HB, HCC, and malignant rhabdoid tumor at our institution with the use of intraoperative NIR-ICG guidance. All patients were treated with 0.2-0.75 mg/kg IV ICG, 48-96 h prior to surgery. Intraoperative NIR-ICG guided imaging was performed with several commercial devices.

RESULTS

Intraoperative NIR-ICG guidance allowed pulmonary metastasectomy in five patients using thoracoscopy or thoracotomy allowing for visualization of multiple nodules not seen on preoperative imaging most of which were positive for malignancy. NIR-ICG guidance allowed for assessment of extrahepatic extension in three patients; an HCC patient with extrahepatic lymph node extension of disease, an HB patient with extrapulmonary thoracic recurrence in the diaphragm and chest wall, and a patient with tumor rupture at diagnosis with peritoneal nodules at the time of surgery. This technique was used to guide partial hepatectomy in 11 patients for which the technique enabled successful identification of tumor and tumor margins. Three patients had nonspecific staining of the liver secondary to decreased timing from ICG injection to surgery or biliary obstruction. NIR-ICG enabled resection of satellite HB lesions in three multifocal patients and confirmed a benign satellite lesion in two additional patients.

CONCLUSIONS

Intraoperative use of NIR-ICG imaging during partial hepatectomy enabled enhanced identification and guidance for surgical resection of extrahepatic disease and multifocal liver tumors for the treatment of children with primary liver cancer.

Near-Infrared Fluorescence Image-Guided Surgery in Esophageal and Gastric Cancer Operations

Background

Near-infrared fluorescence image-guided surgery helps surgeons to see beyond the classical eye vision. Over the last few years, we have witnessed a revolution which has begun in the field of image-guided surgery.

Purpose, and Research design

Fluorescence technology using indocyanine green (ICG) has shown promising results in many organs, and in this review article, we wanted to discuss the 6 main domains where fluorescence image-guided surgery is currently used for esophageal and gastric cancer surgery.

Study sample and data collection

Visualization of lymphatic vessels, tumor localization, fluorescence angiography for anastomotic evaluation, thoracic duct visualization, tracheal blood flow analysis, and sentinel node biopsy are discussed.

Conclusions

It seems that this technology has already found its place in surgery. However, new possibilities and research avenues in this area will probably make it even more important in the near future.

Fluorescence Imaging in Colorectal Surgery: An Updated Review and Future Trends

Fluorescence imaging in colorectal surgery is considered a novel predominantly intraoperative method of ensuring a greater surgical success. The use of fluorescence is linked to advanced tumor visualization and projection of its lymphatics, both vessels and nodes, which results in a higher chance of achieving a total excision. Additionally, iatrogenic complications prove to be reduced using fluorescence during the surgical excision. The combination of fluorescence and artificial intelligence to better facilitate oncological surgery will soon become an established approach in operating rooms worldwide.

Fluorescence Imaging Using Methylene Blue Sentinel Lymph Node Biopsy in Melanoma

Introduction

Fluorescence imaging of sentinel node biopsy in melanoma is a novel method. Both indocyanine green (ICG) and methylene blue (MB) have fluorescent properties. The aim of this study was to present, for the first time in a clinical series of patients, the possible usage of MB as a fluorescent dye for sentinel node biopsy during surgery for melanoma.

Material and methods

Twenty patients with skin melanoma, who were candidates for sentinel node biopsy were enrolled in our study. All patients underwent simultaneous use of standard nanocolloid and blue dye. Transcutaneous visualization of the sentinel node, visualization of lymphatic channels as well as sentinel node fluorescent visualization were all measured. We also performed calculations of Signal to Background ratios (SBR).

Results

In 15% (3/20) of patients, the fluorescent sentinel node was visible through the skin. The median SBR for the sentinel node visualization by fluorescence was 3.15 (range, 2.7–3.5). Lymphatic channels were visible in lymphatic tissue via fluorescence before visualization by the naked eye in 4 patients (20%). The median SBR ratio was 3.69 (range, 2.7–4.2). Sentinel nodes were visible by fluorescence in 13 cases (65%). The median SBR ratio was 2.49 (range, 1.5–5.7). No factors were found to be associated with fluorescent MB visualization of a sentinel node during biopsy.

Conclusion

This is the first clinical study presenting the usefulness of fluorescent sentinel node biopsy in melanoma patients using MB as a fluorophore. Further studies are necessary to provide methods for its’ clinical implementation.

Preparation of the Biodegradable Lymphatic Targeting Imaging Agent Based on the Indocyanine Green Mesoporous Silicon System

The lymphatic system plays a crucial role in the immune system’s recognition and response to disease. Therefore, the imaging of the lymphatic system, especially lymphatic vessels, has emerged as a valuable tool for the diagnosis of metastasis. FDA-approved small-molecule dyes, namely, indocyanine green (ICG), have been widely applied to lymphatic vessels imaging. However, due to the small physical size, such molecule-based agents show no selectivity, and rapid clearance from lymph nodes. Herein, a biodegradable lymphatic targeting imaging agent based on the ICG-mesoporous silicon system (ICG@HMONs-HA) was obtained, which not only could target lymph vessels but also had a long residence time. The reported work provides a practical way for lymph vessel fluorescence imaging and paves the way for clinical translation of nanomaterial-based tracers.

Multispectral Imaging Using Fluorescent Properties of Indocyanine Green and Methylene Blue in Colorectal Surgery-Initial Experience

Introduction: Image-guided surgery is becoming a new tool in colorectal surgery. Intraoperative visualisation of different structures using fluorophores helps during various steps of operations. In our report, we used two fluorophores—indocyanine green (ICG), and methylene blue (MB)—during different steps of colorectal surgery, using one camera system for two separate near-infrared wavelengths. Material and methods: Twelve patients who underwent complex open or laparoscopic colorectal surgeries were enrolled. Intravenous injections of MB and ICG at different time points were administered. Visualisation of intraoperative ureter position and fluorescent angiography for optimal anastomosis was performed. A retrospective analysis of patients treated in our departments during 2020 was performed, and data about ureter injury and anastomotic site complications were collected. Results: Intraoperative localisation of ureters with MB under fluorescent light was possible in 11 patients. The mean signal-to-background ratio was 1.58 ± 0.71. Fluorescent angiography before performing anastomosis using ICG was successful in all 12 patients, and none required a change in position of the planned colon resection for anastomosis. The median signal-to-background ratios was 1.25 (IQR: 1.22–1.89). Across both centres, iatrogenic injury of the ureter was found in 0.4% of cases, and complications associated with anastomosis was found in 5.5% of cases. Conclusions: Our study showed a substantial opportunity for using two different fluorophores in colorectal surgery, whereby the visualisation of one will not change the possible quantification analysis of the other. Using two separate dyes during one procedure may help in optimisation of the fluorescent properties of both dyes when using them for different applications. Visualisation of different structures by different fluorophores seems to be the future of image-guided surgery, and shows progress in optical technologies used in image-guided surgery.

A novel laparoscopic near-infrared fluorescence spectrum system with indocyanine green fluorescence overcomes limitations of near-infrared fluorescence image-guided surgery

BACKGROUND

Near-infrared (NIR) fluorescence image-guided surgery (FIGS) introduces a revolutionary new approach to address this basic challenge in minimally invasive surgery. However, current FIGS systems have some limitations - the infrared rays cannot detect and visualise thick tissues with low concentrations of the fluorescent agent. We established a novel laparoscopic fluorescence spectrum (LFS) system using indocyanine green (ICG) fluorescence to overcome these limitations.

MATERIALS AND METHODS

Bovine serum albumin (BSA) was conjugated to ICG, and the mixtures were serially diluted at 5 × 10-8-5 × 10-1 mg/mL. We used the LFS system and a NIR camera system (NLS; SHINKO OPTICAL CO., LTD Tokyo, Japan) to determine the optical dilution for the fluorescence detection. BSA was conjugated to ICG (5.0 × 10-2 mg/mL) and used to coat the clips. We attempted to identify the fluorescence-coated clip from the serosal side of the cadaveric porcine stomach tissues using the LFS system and the NIR camera system. We measured the depth of the cadaveric porcine stomach wall at the thickest part that could be confirmed.

RESULTS

We could not visualise fluorescence concentrations <2.5 × 10-3 mg/mL using the NIR camera system. The spectrum was detected at a concentration <2.5 × 10-3 mg/mL. We were able to identify the spectrum of ICG (829 nm) to a 13-mm depth of cadaveric porcine stomach wall by using the LFS system but could not identify the same with the NIR camera system regardless of wall thickness.

CONCLUSIONS

The novel LFS system with NIR fluorescence imaging in this ex vivo and cadaveric porcine model was confirmed useful at deeper depths and lower concentrations. Based on these findings, we anticipate that the LFS system can be integrated and routinely used in minimally invasive surgery.

Discovery of novel phenaleno isoquinolinium-based fluorescence imaging agents for sentinel lymph node mapping

Fluorescence imaging agents have recently received huge attention due to their important role in disease diagnostics. However, the intrinsic problems of these probes, such as complex synthetic routes and high molecular weight, remain challenging. Here, we developed novel phenaleno isoquinolinium-based fluorescent agents, Medical Fluorophores 37-41 (MF37-41), applicable to the quantitative and sensitive detection of sentinel lymph nodes (SLNs). These imaging agents showed no adverse effects on the proliferation of immune and normal cells and did not induce in vivo toxicity. In vivo fluorescence lifetime imaging demonstrated the accumulation of phenaleno isoquinolinium salts in the SLNs of nude mice within 15 min postinjection, consistent with our biodistribution findings. These results suggest that phenaleno isoquinolinium salts are feasible fluorescence imaging agents that can be used as potential lymphatic tracers.

The Use of Fluorescent Anti-CEA Antibodies to Label, Resect and Treat Cancers: A Review

A major barrier to the diagnosis and effective treatment of solid-tumor cancers is the difficulty in detection and visualization of tumor margins in primary and metastatic disease. The use of fluorescence can augment the surgeon's ability to detect cancer and aid in its resection. Several cancer types express carcinoembryonic antigen (CEA) including colorectal, pancreatic and gastric cancer. Antibodies to CEA have been developed and tagged with near-infrared fluorescent dyes. This review article surveyed the use of CEA antibodies conjugated to fluorescent probes for in vivo studies since 1990. PubMed and Google Scholar databases were queried, and 900 titles and abstracts were screened. Fifty-nine entries were identified as possibly meeting inclusion/exclusion criteria and were reviewed in full. Forty articles were included in the review and their citations were screened for additional entries. A total of 44 articles were included in the final review. The use of fluorescent anti-CEA antibodies has been shown to improve detection and resection of tumors in both murine models and clinically. The cumulative results indicate that fluorescent-conjugated anti-CEA antibodies have important potential to improve cancer diagnosis and surgery. In an emerging technology, anti-CEA fluorescent antibodies have also been successfully used for photoimmunotherapy treatment for cancer.

Lymphoscintigraphic Investigations for Axillary Web Syndromes

Background: Axillary web syndrome (AWS) is a frequent complication after surgery for breast cancer, but its lymphatic involvement is not definitively established. Here we report the results of lymphoscintigraphic investigations in patients with AWS. Methods and Findings: We conducted a retrospective, single-center review of lymphoscintigraphic investigations performed in 46 patients with AWS that was either clinically obvious or suspected. Of this group, 23 patients had two investigations with a mean interval of 19 weeks between them (range, 6-98 weeks). Results of the lymphoscintigraphic investigations, which were performed according to a well-standardized protocol, were classified into four patterns: normal; functional lymphatic insufficiency only (no lymphatic vascular morphologic abnormality); lymphovascular blockade without collateralization; and vascular collateralization and/or dermal backflow. Of the 46 patients, on the first lymphoscintigraphic investigation, four (8.6%) had a normal pattern, seven (15.2%) had functional lymphatic insufficiency only, four (8.6%) had lymphovascular blockade without collateralization, and 31 (67.3%) had vascular collateralization and/or dermal backflow. Among patients who underwent two investigations, four of the five who had only functional lymphatic insufficiency at the first investigation had developed vascular collateralization and/or dermal backflow by the second. The three patients who had lymphovascular blockade without collateralization at the first examination had also progressed to collateralization and/or dermal backflow at the second. None of the 15 patients who initially had vascular collateralization and/or dermal backflow showed any reversal at the second examination. Conclusions: Our analysis confirms the lymphatic nature of AWS and shows the lymphoscintigraphic patterns and evolutions of the lymphatic lesions with potential therapeutic implications. The retrospective review of our database is approved by the institutional ethics committee under number 2048.

Safety and efficacy of indocyanine green fluorescence imaging-guided radical gastrectomy: a systematic review and meta-analysis

BACKGROUND

The clinical value of indocyanine green (ICG) in laparoscopic radical gastrectomy remains controversial. We performed this meta-analysis to investigate the safety and efficacy of ICG fluorescence imaging-guided radical gastrectomy.

METHODS

All relevant studies published until 30 October 2020 were retrieved from several databases. Fixed- and random-effects models were used to analyze the results based on different heterogeneity levels. Data were expressed as odds ratios or weighted mean differences along with 95% confidence intervals. The Grading of Recommendations, Assessment, Development, and Evaluation system scale was used for quality of evidence evaluation.

RESULTS

This meta-analysis included six cohort studies that investigated 622 patients. Compared with conventional radical gastrectomy, ICG fluorescence imaging-guided gastrectomy facilitates complete lymph node dissection, reduces intraoperative blood loss, and shortens the length of postoperative hospitalization. Moreover, we observed no significant intergroup differences in the operative time, first exhaust time, and postoperative complications.

CONCLUSION

ICG fluorescence imaging-guided radical gastrectomy scores over conventional gastrectomy and appears to be a promising approach in patients who require radical gastrectomy. However, further research is warranted to explore the potential long-term survival benefit of ICG fluorescence imaging in patients with gastric cancer.

Indocyanine Green Fluorescence-Guided Sentinel Node Biopsy in Breast Cancer Within a North African Population: A Retrospective Study

Objective

Radio isotopes and blue dyes alone or in combination are the most commonly used tracer agents in sentinel node (SN) biopsy for early breast cancer. Recent studies have found fluorescence method using indocyanine green (ICG) as a promising technology with fewer disadvantages.

Materials and Methods

Retrospective analysis of our database that included patients with clinically node-negative breast cancer scheduled for breast surgery and SN biopsy between 2016 and January 2021. Patients who underwent detection using fluorescence-ICG were included in this study.

Results

A total of 47 patients were included. Median age was 50 (range: 24-78) years. Mean tumor size was 3.4 ± 1.5 cm. All patients received ICG injection and 11 received a combination of ICG and blue dye. Forty-five successful SN identifications with ICG were performed and 99 nodes retrieved. Eleven procedures were undertaken after initial systemic therapy. Twenty-four patients had at least one positive SN for malignancy. Mean follow up was 29.2 months and no axillary recurrence was noted during the study period.

Conclusion

ICG appears to be a feasible and accurate method for SN biopsy with high identification rate. This is the first study of ICG in sentinel node biopsy in a North African population.

Comprehensive Review of Fluorescence Applications in Gynecology

Since the introduction of indocyanine green (ICG) as a fluorophore in near-infrared imaging, fluorescence visualization has become an essential tool in many fields of surgery. In the field of gynecology, recent new applications have been proposed and found their place in clinical practice. Different applications in gynecology were investigated, subcategorized, and overviewed concerning surgical applications and available dyes. Specific applications in which fluorescence-guided surgery was implemented in gynecology are described in this manuscript—namely, sentinel node biopsy, mesometrium visualization, angiography of different organs, safety issues in pregnant women, ureters visualization, detection of peritoneal metastases, targeted fluorophores for cancer detection, fluorescent contamination hysterectomy, lymphography for lower limb lymphedema prevention, tumor margin detection, endometriosis, and metastases mapping. With evolving technology, further innovative research on the new applications of fluorescence visualization in cancer surgery may help to establish these techniques as standards of high-quality surgery in gynecology. However, more investigations are necessary in order to assess if these innovative tools can also be effective to improve patient outcomes and quality of life in different gynecologic malignancies.

Lymphatic regeneration after implantation of aligned nanofibrillar collagen scaffolds: Preliminary preclinical and clinical results

BACKGROUND

We tested our hypothesis that implantation of aligned nanofibrillar collagen scaffolds (BioBridge™) can both prevent and reduce established lymphedema in the rat lymphedema model. Our authors report clinical cases that demonstrate new lymphatic formation guided by BioBridge™ as seen by near-infrared (NIR) fluoroscopy and magnetic resonance (MR) lymphography.

METHODS

A rat lymphedema model was utilized. A prevention group received implantation of BioBridge™ immediately after lymphadenectomy. A lymphedema group received implantation of BioBridge™ with autologous adipose-derived stem cells (ADSC; treatment group) or remained untreated (control group). All subjects were observed for 4 months after lymphadenectomy. The hindlimb change was evaluated using computed tomography-based volumetric analysis. Lymphagiogenesis was assessed by indocyanine green (ICG) lymphography.

RESULTS

Animals in the treatment group showed a reduction in affected limb volume. Animals in the prevention group showed no increase in the affected limb volume. ICG fluoroscopy demonstrated lymph flow and formation of lymphatics toward healthy lymphatics.

CONCLUSIONS

In the rat lymphedema model, implantation of BioBridge™ at the time of lymph node removal prevents the development of lymphedema. Treatment of established lymphedema with the BioBridge™ and ADSC reduces lymphedema. New lymphatic vessels are demonstrated by NIR fluoroscopy and MR lymphography. These findings have implications for the treatment of lymphedema in human subjects.

Real-time fluorescence image-guided gastrointestinal oncologic surgery: Towards a new era

Technological improvements are crucial in the evolution of surgery. Real-time fluorescence-guided surgery (FGS) has spread worldwide, mainly because of its usefulness during the intraoperative decision-making processes. The success of any gastrointestinal oncologic resection is based on the anatomical identification of the primary tumor and its regional lymph nodes. FGS allows also to evaluate the blood perfusion at the gastrointestinal stumps after colorectal or esophageal resections. Therefore, a reduction on the anastomotic leak rates has been postulated as one of the foreseeable benefits provided by the use of FGS in these procedures. Although the use of fluorescence in lymph node detection was initially described in breast cancer surgery, the technique is currently applied in gastric or splenic flexure cancers, as they both present complex and variable lymphatic drainages. FGS allows also to perform intraoperative lymphograms or sentinel lymph node biopsies. New applications of FGS are being developed to assist in the detection of peritoneal metastases or in the evaluation of the tumor resection margins. The present review aims to provide a general overview of the current status of real-time FGS in gastrointestinal oncologic surgery. We put a special focus on the different applications of FGS, discussing the main findings and limitations found in the contemporary literature and also the promising near future applications.

Indocyanine Green Angiography for Quality Assessment of the Kidney During Transplantation: An Outcome Predictor Prospective Study

BACKGROUND

Microvascular damage is the main cause of delayed graft function (DGF) after kidney transplant. Assessing its extent may be helpful in predicting DGF to achieve better postoperative management, especially in terms of an immunosuppressive regimen. Our aim was to explore the capability of intraoperative indocyanine green (ICG) angiography to examine the microvasculature of the kidney.

METHODS

We conducted a prospective cohort study on 37 kidney transplant recipients in a high-volume kidney transplant center. During surgery, after graft implant, an ICG angiography was performed through a high-definition Storz camera system (Karl Storz GmbH, Tuttlingen, Germany) with successive quantitative assessment of fluorescence using Icy bioimage analysis.

RESULTS

All transplanted kidneys that showed immediate recovery of their function had a fluorescent intensity ≥49.953 with a mean of 96.930 ± 21. The fluorescence intensity for kidneys that showed a delayed recovery of their function never exceeded 55.648, and the mean was 37.718 ± 13. The difference between the 2 groups was statistically significant with a P value < .001. The only kidney that never recovered showed a fluorescence intensity consistently <25.220, the lowest detected.

CONCLUSIONS

This study demonstrates that intraoperative ICG angiography may be used to assess the microvasculature of the graft. A statistically significant difference in terms of fluorescent intensity can be highlighted between kidneys that immediately recover their function and those with delayed recovery. Further larger studies are needed to confirm the capability of the technique to predict DGF to optimize the transplanted patients' management.

Clinically translatable formulation strategies for systemic administration of nerve-specific probes

Nerves are extremely difficult to identify and are often accidently damaged during surgery, leaving patients with lasting pain and numbness. Herein, a novel near-infrared (NIR) nerve-specific fluorophore, LGW01-08, was utilized for enhanced nerve identification using fluorescence guided surgery (FGS), formulated using clinical translatable strategies. Formulated LGW01-08 was examined for toxicology, pharmacokinetics (PK), and pharmacodynamics (PD) parameters in preparation for future clinical translation. Optimal LGW01-08 imaging doses were identified in each formulation resulting in a 10x difference between the toxicity to imaging dose window. Laparoscopic swine surgery completed using the da Vinci surgical robot (Intuitive Surgical) demonstrated the efficacy of formulated LGW01-08 for enhanced nerve identification. NIR fluorescence imaging enabled clear identification of nerves buried beneath ~3 mm of tissue that were unidentifiable by white light imaging. These studies provide a strong basis for future clinical translation of NIR nerve-specific fluorophores for utility during FGS to improve patient outcomes.

Novel quinoline-based fluorescent bioimaging probe, KSNP117, for sentinel lymph node mapping

Fluorescent imaging agents with biocompatibility and high sensitivity are urgently required for the accurate detection of sentinel lymph nodes (SLNs). Herein, we report the design of a novel quinoline-based fluorescent probe, designated KSNP117, which can be applied as a biomedical imaging agent in the sensitive and quantitative detection of SLNs. KSNP117 exerted no adverse effects on the proliferation of ovary and immune cells and also showed excellent serum stability with photo-brightening effects. In vivo fluorescent imaging revealed the accumulation of KSNP117 in the SLNs of nude mice within 10 min post injection, without in vivo toxicity, which was consistent with the findings of ex vivo imaging. These results support the potential of KSNP117 as a promising lymphatic tracer for biomedical imaging applications.

Comparison of two different surgical strategies for breast cancer patients treated with mastectomy plus sentinel lymph node biopsy

Two separated incisions are generally adopted in breast cancer patients treated by mastectomy plus sentinel lymph node biopsy (SLNB). However, one-incision procedure is also applied in clinical practice. The outcomes of the two different surgical strategies remain unknown. This issue needs to be investigated. The medical records of breast cancer patients who underwent a mastectomy combined with an SLNB were reviewed retrospectively. Group A comprised patients who received a single incision for both the mastectomy and SLNB. Group B comprised patients who received a second incision for the SLNB. Demographics and outcomes were compared between the two groups. There were 280 female patients divided into Groups A (n = 130) and B (n = 150) included in this study. Preoperatively, the two groups were similar in demographics for age, tumor size, tumor location, body mass index, pathologic type, and cancer stage (P > 0.05). Group A showed shorter surgical times (129.5 ± 29.0 vs. 136.7 ± 21.9 min), less postoperative upper limb numbness (12.3% vs. 25.3%), and more harvested sentinel lymph nodes (3.2 ± 1.1 vs. 2.7 ± 1.0) than Group B (P < 0.05). There were no significant differences for intraoperative blood loss, total postoperative drainage amount, hospital stay, upper limb motility, upper limb pain, upper limb edema, number of metastatic sentinel lymph nodes, follow-up time, or recurrent cases (P > 0.05). The one-incision approach for a breast cancer mastectomy plus SLNB has several advantages over the two-incision approach, including a shorter surgical time, decreased upper limb numbness, and the harvesting of more sentinel lymph nodes. Further prospective randomized controlled clinical trials should be designed to verify the current findings.

Potential of Cyanine Derived Dyes in Photodynamic Therapy

Photodynamic therapy (PDT) is a method of cancer treatment that leads to the disintegration of cancer cells and has developed significantly in recent years. The clinically used photosensitizers are primarily porphyrin, which absorbs light in the red spectrum and their absorbance maxima are relatively short. This review presents group of compounds and their derivatives that are considered to be potential photosensitizers in PDT. Cyanine dyes are compounds that typically absorb light in the visible to near-infrared-I (NIR-I) spectrum range (750-900 nm). This meta-analysis comprises the current studies on cyanine dye derivatives, such as indocyanine green (so far used solely as a diagnostic agent), heptamethine and pentamethine dyes, squaraine dyes, merocyanines and phthalocyanines. The wide array of the cyanine derivatives arises from their structural modifications (e.g., halogenation, incorporation of metal atoms or organic structures, or synthesis of lactosomes, emulsions or conjugation). All the following modifications aim to increase solubility in aqueous media, enhance phototoxicity, and decrease photobleaching. In addition, the changes introduce new features like pH-sensitivity. The cyanine dyes involved in photodynamic reactions could be incorporated into sets of PDT agents.

The role of fluorescent and hybrid tracers in radioguided surgery in urogenital malignancies

The increasing availability of new imaging technologies and tracers has enhanced the application of nuclear molecular imaging in urogenital interventions. In this context, preoperative nuclear imaging and radioactivity-based intraoperative surgical guidance have become important tools for the identification and anatomical allocation of tumor lesions and/or suspected lymph nodes. Fluorescence guidance can provide visual identification of the preoperatively defined lesions during surgery. However, the added value of fluorescence guidance is still mostly unknown. This review provides an overview of the role of fluorescence imaging in radioguided surgery in urogenital malignancies. The sentinel node (SN) biopsy procedure using hybrid tracers (radioactive and fluorescent component) serves as a prominent example for in-depth evaluation of the complementary value of radio- and fluorescence guidance. The first large patient cohort and long-term follow-up studies show: 1) improvement in the SN identification rate compared to blue dye; 2) improved detection of cancer-positive SNs; and 3) hints towards a positive effect on (biochemical) recurrence rates compared to extended lymph node dissection. The hybrid tracer approach also highlights the necessity of a preoperative roadmap in preventing incomplete resection. Recent developments focus on receptor-targeted approaches that allow intraoperative identification of tumor tissue. Here radioguidance is still leading, but fluorescent and hybrid tracers are also finding their way into the clinic. Emerging multiwavelength approaches that allow concomitant visualization of different anatomical features within the surgical field may provide the next step towards even more refined procedures.

[Near-infrared sentinel diagnostics in head and neck squamous cell carcinoma: a systematic review]

BACKGROUND

 Near-infrared fluorescence (NIR) imaging is a new technique for intraoperative identification of sentinel lymph nodes (SLN). It has shown promising results in several surgical specialties. This article reviews the current study situation of NIR SLN diagnosis of head and neck malignancy.

MATERIAL AND METHODS

 systematic literature search in the following online databases: PubMed, MEDLINE, Thompson Reuters Web of Science, SPIE for the search terms: sentinel node, sentinel node biopsy, head and neck squamous cell carcinoma, near-infrared imaging, indocyanine green, icg. Evaluation of scientific relevance of papers according to established criteria.

RESULTS

 Studies were analyzed in terms of clinical application, clinical reporting, identification rate, and false-negative rate. The identification rate of SLN is 97-100 %, with an average of 1.2-3.4 fluorescence positive lymph nodes per examination. The overall false-negative rate varies between 0 and 20 %.

CONCLUSIONS

 In the synopsis of the currently published results, NIR imaging promises the great potential to improve the diagnosis of SLN in carcinomas of the oral cavity and pharynx. A simple and fast procedure with high spatial resolution and without radiation exposure is beneficial.

Usefulness and Prospects of Sentinel Lymph Node Biopsy for Patients With Breast Cancer Using the Medical Imaging Projection System

Background

The Medical Imaging Projection System (MIPS) projects indocyanine green (ICG) fluorescence images directly on the surgical field using a projection mapping technique. We conducted an observational study of sentinel lymph node (SLN) biopsy using the prototype MIPS; we found a high identification rate. However, the number of SLN-positive cases was small, and the sensitivity could not be evaluated. The aim of this study was to investigate the clinical usefulness of the MIPS assisted ICG fluorescence method using commercially available equipment.

Methods

This was a retrospective observational study. Patients with primary breast cancer who underwent SLN biopsy using the MIPS at Kyoto University Hospital from April to December 2020 were included in the study. The primary endpoints were the identification rate of SLNs and detection of positive SLNs by the MIPS. The secondary endpoint was the number of SLNs excised using the MIPS per patient. We also conducted a questionnaire survey focused on the utility of the MIPS; it involved doctors with an experience in using the MIPS.

Results

Seventy-nine patients (84 procedures) were included in the study. In 60 (71%) procedures, both the radioisotope (RI) method and MIPS were used. At least one SLN could be detected by the MIPS in all the procedures, with an identification rate of 100% (95% confidence interval 95.6–100%). A total of 19 (7%) positive SLNs were removed, which were identifiable by the MIPS. Among 57 patients in whom the MIPS and RI methods were used, there was no positive SLN only identified by the RI method. The results of the questionnaire survey showed that the MIPS enabled the operator and assistant to share the ICG fluorescence image in the surgical field and to communicate with each other easily.

Conclusion

The current study demonstrated that the identification rate of SLNs using the MIPS was high, and the MIPS can be used for detecting positive SLNs. It was suggested that the MIPS will be useful in learning SLN biopsy procedures.

Novel application of indocyanine green fluorescence imaging for real-time detection of thrombus in a membrane oxygenator

Extracorporeal membrane oxygenation (ECMO) plays an important role in the coronavirus disease 2019 (COVID-19) pandemic. Management of thrombi in ECMO is generally an important issue; especially in ECMO for COVID-19 patients who are prone to thrombus formation, the thrombus formation in oxygenators is an unresolved issue, and it is very difficult to deal with. To prevent thromboembolic complications, it is necessary to develop a method for early thrombus detection. We developed a novel method for detailed real-time observation of thrombi formed in oxygenators using indocyanine green (ICG) fluorescence imaging. The purpose of this study was to verify the efficacy of this novel method through animal experiments. The experiments were performed three times using three pigs equipped with veno-arterial ECMO comprising a centrifugal pump (CAPIOX SL) and an oxygenator (QUADROX). To create thrombogenic conditions, the pump flow rate was set at 1 L/min without anticoagulation. The diluted ICG (0.025 mg/mL) was intravenously administered at a dose of 10 mL once an hour. A single dose of ICG was 0.25mg. The oxygenator was observed with both an optical detector (PDE-neo) and the naked eye every hour after measurement initiation for a total of 8 hours. With this dose of ICG, we could observe it by fluorescence imaging for about 15 minutes. Under ICG imaging, the inside of the oxygenator was observed as a white area. A black dot suspected to be the thrombus appeared 6-8 hours after measurement initiation. The thrombus and the black dot on ICG imaging were finely matched in terms of morphology. Thus, we succeeded in real-time thrombus detection in an oxygenator using ICG imaging. The combined use of ICG imaging and conventional routine screening tests could compensate for each other's weaknesses and significantly improve the safety of ECMO.

Indocyanine green fluorescence imaging for evaluating blood flow in the reconstructed conduit after esophageal cancer surgery

We investigated the effectiveness of indocyanine green (ICG) fluorescence blood flow imaging of the gastric conduit to evaluate anastomotic leakage after esophagectomy. We identified 19 articles using the PRISMA standard for systematic reviews. The more recent studies reported attempts at objective quantification of ICG fluorescence imaging, rather than qualitative assessment. Anastomotic leakage after esophagectomy occurred in 0-33% of the patients who underwent ICG fluorescence imaging. According to the six studies that compared the incidence of anastomotic leakage in the ICG group and the control group, it ranged from 0 to 18.3% in the ICG group and from 0 to 25.2% in the control group, respectively. Overall, the incidence of anastomotic leakage in the ICG group (8.4%) was lower than that in the control group (18.5%). Although the incidence of anastomotic leakage was as high as 43.1% in patients who did not undergo any intraoperative intervention for poor blood flow, it was only 24% in patients who underwent intraoperative intervention. This systematic review revealed that ICG fluorescence imaging may be a crucial adjunctive tool for reducing anastomotic leakage after esophagectomy, suggesting that it should be performed during esophageal reconstruction.

Real-Time In Situ Navigation System With Indocyanine Green Fluorescence for Sentinel Lymph Node Biopsy in Patients With Breast Cancer

BACKGROUND

The naked-eye invisibility of indocyanine green fluorescence limits the application of near-infrared fluorescence imaging (NIR) systems for real-time navigation during sentinel lymph node biopsy (SLNB) in patients with breast cancer undergoing surgery. This study aims to evaluate the effectiveness and safety of a novel NIR system in visualizing indocyanine green fluorescence images in the surgical field and the application value of combined methylene blue (MB) and the novel NIR system in SLNB.

METHODS

Sixty patients with clinical node-negative breast cancer received indocyanine green (ICG) and MB as tracers. Two NIR system instruments, namely, lymphatic fluorescence imaging system (LFIS) designed by the University of Science and Technology of China and vascular imager by Langfang Mingde Medical Biotechnology Co., Ltd. (Langfang vascular imager), were used as navigation assistance to locate sentinel lymph nodes (SLNs). Excising the lymph nodes developed by both MB and ICG by two NIR systems or palpably suspicious as SLNs and undergoing rapid pathological examination.

RESULTS

Both instruments exhibited 95% (57/60) success for real-time lymphatic fluorescent images. A total of 186 SLNs were identified, of which two were pathologically confirmed as lacking any lymph node tissue. SLN identification rate was 100% (184/184) for MB plus LFIS and 86.96% (160/184) for MB alone. The median number of SLNs identified by LFIS combined with MB was 3 (range of 1-8), which was significantly higher than that by MB alone at 2 (range 1-7) (P<0.05).

CONCLUSION

LFIS effectively detects SLNs in breast cancer, projects the fluorescence signals during surgery, and provides a continuous surgical navigation system without the need for a remote monitor. The ICG method navigated by combined LFIS and MB may be a promising alternative tracer for radioisotope in SLN mapping.

CLINICAL TRIAL REGISTRATION

This clinical trial was registered with the China Clinical Trial Center, registration number ChiCTR2000039542.

Near-infrared laparoscopy with indocyanine green for axillary sentinel lymph node biopsy in early breast cancer: preliminary experience of a single unit

Background

A sentinel lymph node biopsy (SLNB) is a routine procedure for axillary staging in cN0 breast cancer (BC) patients. Indocyanine green (ICG) fluorescence can detect sentinel lymph nodes with higher sensitivity than carbon nanoparticle suspension (CNS). The present study investigated the availability and benefits of a near-infrared (NIR) laparoscopy-assisted SLNB using ICG and carbon nanoparticle suspension as tracers.

Methods

Forty patients with invasive BC, who had clinically negative axillary lymph nodes, participated in this observational study. ICG and CNS tracers were injected into the periareolar region simultaneously or sequentially. In the endoscopy-assisted group (n=20), the patients were given NIR laparoscopic SLNB based on ICG fluorescence and CNS staining. In the open-surgery group, the patients were given traditional SLNB using an open incision, and CNS tracers were injected into the same region as that in the endoscopy-assisted group.

Results

In the endoscopy-assisted group, lymphatic vessels and sentinel lymph nodes (SLNs) were successfully identified using ICG fluorescence imaging in most patients (19/20). The average number of SLNs removed was 2.85 (range, 1-4) in the endoscopy-assisted group, and 3.40 (range, 1-7) in the open-surgery group. There was no significant difference between the number of detected nodes (P=0.30). The patients who underwent endoscopy-assisted SLNBs had similar operating times, blood loss and hospital-stay lengths, but lower postoperative drainage volumes and higher satisfaction scores, as they did not have axillary incisions.

Conclusions

The NIR laparoscopy-assisted ICG-guided technique is a feasible and surgeon-friendly method for SLNB with good efficacy and acceptable safety. When combined with CNS, more SLNs can be detected and dissected.

Long-term results of fluorescence and indigo carmine blue dye-navigated sentinel lymph node biopsy

BACKGROUND

Sentinel lymph node biopsy is widely applied for the management of clinically node-negative breast cancer, and a radioisotope with a blue dye are most often used as tracers. Fluorescence of indocyanine green could also potentially be used as tracer. This study aimed to demonstrate the long-term survival results of fluorescence-guided sentinel lymph node biopsy.

PATIENTS AND METHODS

Patients with clinically node-negative breast cancer who underwent surgery as initial treatment were included in this study. Both fluorescence of indocyanine green and indigo carmine blue dye were used as tracers. Axillary lymph node dissection was omitted unless metastasis was pathologically proven in sentinel nodes. Breast cancer recurrence and death were recorded and prognostic factors were identified using disease-free survival and overall survival data.

RESULTS

A total of 565 patients were analyzed. There were 14 (2.5%) patients whose sentinel nodes could not be identified, yielding an identification rate of 97.5%. Axillary dissection was performed in 90 patients. Forty-three recurrences including 6 ipsilateral axilla recurrence and 13 deaths were observed during the median 83 months of follow-up period. Seven-year disease-free and overall survival were 92.4% and 97.3%, respectively. Multivariate analyses demonstrated that pre-menopausal status and invasive lobular carcinoma were significant unfavorable prognostic factors of disease-free survival. Half of ipsilateral axilla recurrences occurred within 5 years after surgery and these recurrences were correlated with inappropriate adjuvant therapy.

CONCLUSION

Fluorescence-guided sentinel lymph node biopsy demonstrated favorable prognostic results and could be alternative to the radioisotope for clinically node-negative breast cancer.

Clinical study of combined application of indocyanine green and methylene blue for sentinel lymph node biopsy in breast cancer

OBJECTIVE

This study aims to investigate the feasibility of combined application of indocyanine green (ICG) and methylene blue (MB) for sentinel lymph node biopsy (SLNB) in patients with early breast cancer.

METHODS

A total of 415 patients who underwent SLNB and axillary lymph node dissection were enrolled. Sentinel lymph node (SLN) was assessed in 197 patients with ICG and MB combination method, while, the other 218 patients were detected by MB method alone. During surgery, all SLNs were harvested for pathological examination. Then the detection rate and false negative rate of SLNs were comparatively analyzed between the 2 groups.

RESULTS

In the combined ICG and MB group, the detection rate of SLNs was 96.9%, significantly higher than that of MB group, which was 89.7% (P < .05). Similarly, in combined group, the average number of SLNs per patient was 3.0, much higher than that of MB group, which was 2.1 (P < .05). There was no statistically significant difference in false negative rate between combined group and MB alone group, which was 7.3% and 10.5%, respectively (P = .791).

CONCLUSION

The combined application of ICG and MB for SLNB is much more effective than MB alone in detecting SLNs.

In Vivo Visualization of the Pericardium Meridian with Fluorescent Dyes

The anatomical basis of acupuncture meridians continues to be enigmatic. Although much attention has been placed on potential correlations with inter/intramuscular fascia or lower electrical impedance, animal studies performed in the past 40 years have shown that tracer dyes—specifically Tc-99m pertechnetate—injected at strategic skin points generate linear migrations closely aligning with acupuncture meridians. To evaluate whether this phenomenon is also observable in humans, we injected two fluorescent dyes—fluorescein sodium and indocyanine green (ICG)—into the dermal layer both at acupuncture points (PC5, PC6, and PC7) and a nonacupoint control. Fifteen healthy volunteers were enrolled in this study. Of the 19 trials of fluorescein injected at PC6, 15 (79%) were associated with slow diffusion of the dye proximally along a path matching closely with the pericardium meridian. Furthermore, the dye emerged and coalesced proximally at exactly acupoint PC3. Injections of ICG at the acupoints PC5, PC6, or PC7 showed a similar trajectory close to the injection site but diverged when migrating proximally, failing converge on acupoint PC3. Injections of either dye at an adjacent PC6-control did not generate any notable linear pathway. Both ultrasound imaging and vein-locating device did not reveal any corresponding vessels (arterial or venous) at the visualized tracer pathway but did demonstrate correlations with intermuscular fascia.

Association between indocyanine green fluorescence blood flow speed in the gastric conduit wall and superior mesenteric artery calcification: predictive significance for anastomotic leakage after esophagectomy

BACKGROUND

Near-infrared fluorescence using indocyanine green (ICG) has been applied as a real-time navigation tool to observe blood flow in gastric conduit wall after esophagectomy. Atherosclerosis might impair the blood flow of the systemic organs. The aim of the study was to investigate the significances of ICG blood flow speed in the gastric conduit wall and atherosclerotic calcification for the prediction of anastomotic leakage after esophagectomy.

METHODS

The 109 esophageal cancer patients were prospectively enrolled. ICG fluorescence blood flow speed in the gastric conduit wall and abdominal aortic calcification index (ACI), celiac artery (CA) calcification, and superior mesenteric artery (SMA) calcification were determined. Then, the correlation between ICG fluorescence blood flow speed and anastomotic leakage as well as ACI, CA, and SMA calcification were evaluated.

RESULTS

Anastomotic leakage occurred in 15 patients. ACI ranged from 0 to 65. CA calcification and SMA calcification were present in 25 and 12 patients. Multivariate analysis demonstrated that ICG fluorescence blood flow speed in the gastric conduit wall of 2.07 cm/s or less (P < 0.001) and SMA calcification (P = 0.026) were the significant independent predictors of anastomotic leakage. Only SMA calcification was significantly associated with ICG fluorescence blood flow speed in the gastric conduit wall (P = 0.026).

CONCLUSIONS

This study demonstrated that ICG fluorescence blood flow speed in the gastric conduit wall can predict anastomotic leakage after esophagectomy and microvascular perfusion of capillary vessels of the gastric conduit might be impaired by systemic atherosclerosis.

Long-term follow-up results of fluorescence and blue dye guided sentinel lymph node biopsy in early breast cancer

PURPOSE

This study aimed to assess the efficacy of the combination of indocyanine green (ICG) and methylene blue (MB) dye in early breast cancer patients undergoing sentinel lymph node biopsy (SLNB).

METHODS

Between January 2011 and December 2015, 1061 early breast cancer patients underwent SLNB were included. SLNB was performed for enrolled patients by injection of both ICG and MB. Detection rate, positivity, and number of sentinel lymph nodes (SLNs) by ICG and MB were analysed. Axillary recurrence and arm lymphedema at 5.6-year follow-up were reported.

RESULTS

The combination of ICG and MB resulted in a very high detection rate of 99.6%, the median number of sentinel lymph nodes was 3. A total of 374 histologically confirmed positive SLNs were detected in 237 patients, 96.6% of the positive patients and 94.1% of the positive nodes could be identified by the combination of ICG and MB. After a median follow-up of 5.6 (2-9.3) years, 0.64% of patients with negative SLNs had ipsilateral axillary recurrence, and the incidence of arm lymphedema was 2.1%.

CONCLUSIONS

Although the missing isotope control weakens the interpretation of the findings, the dual tracing modality of ICG and MB, without involvement of radioactive isotopes, was an effective method for SLNB in patients with early breast cancer.

TRIAL REGISTRATION

ACTRN12612000109808. Registered on 23 January 2012.

Usefulness and limitation of indocyanine green fluorescence for detection of peritoneal recurrence after hepatectomy for hepatocellular carcinoma: a case report

Background

Peritoneal recurrence of hepatocellular carcinoma (HCC) after hepatectomy occurs rarely, accounting for less than 1% of all recurrences. Reported causes of such dissemination include a history of rupture of the original HCC, needle biopsy or puncture treatment, and surgical procedures. There is no consensus on the optimal treatment strategy for peritoneal dissemination. There have been few reports on assisting resection of peritoneal dissemination by using indocyanine green (ICG) fluorescence.

Case presentation

A 57-year-old man underwent posterior sectionectomy for HCC. Six months later, computed tomography revealed multiple nodules suspected of indicating peritoneal dissemination. Various preoperative imaging studies demonstrated only four nodules, the doubling time of the tumors being rapid at 22 days. The nodules were therefore resected. ICG (0.5 mg/kg) was injected intravenously 2 days before the procedure, enabling identification of the nodules by their brightness in the operative field under near-infrared lighting. A total of eight lesions were detected during the procedure and resected, some of which had not been identified by preoperative imaging studies. We diagnosed peritoneal dissemination of HCC based on the pathological findings and their similarity to those of the original HCC. We concluded that the recurrences were likely attributable to exposure of the tumor to the serosa at the time of the original operation.

Conclusions

Although ICG fluorescence is useful for identifying peritoneal dissemination of HCC, attention should be paid to the difficulty in detecting deep lesions and occurrence of false positives.

A single-center, self-controlled, phase I clinical trial of mitoxantrone hydrochloride injection for lymph tracing for sentinel lymph node identification of breast cancer

Background

Mitoxantrone hydrochloride injection for lymph tracing (MHI) is a novel lymphatic tracer for sentinel lymph node (SLN) in patients with early breast cancer but exhibited remarkable liver, kidney, and hematologic toxicities in previous studies. Here, the pharmacokinetics and pharmacodynamics profiles of MHI were evaluated to surmise safety and tolerability.

Methods

Phase 1 open-label, single center, and dose escalation study was performed. Ten patients with invasive breast cancer received 0.5, 1.0, or 2.0 mL of MHI into the breast tissues surrounding the tumor for lymphatic mapping. All of these patients were injected with 2 mCi nuclide-labeled sulfur colloid as a self-control 24 to 48 hours before surgery. Safety was assessed by the incidence of adverse events graded by the National Cancer Institute Common Terminology Criteria, version 4.0.3 (CTCAE4.0.3). Blood samples for pharmacokinetic analyses were collected before and after administration at 15, 30, 60, 120, and 240 min of the injection of MHI.

Results

Up to the cutoff date of the study (Aug 8, 2018), no dose-limiting toxic effects or obvious allergic reactions were observed. Only one case of an adverse event was certainly related to MHI, where it caused blue discoloration of the local skin over the injection site after the operation, but this stain gradually went away. The peak level of MHI was achieved after 15-30 min post injection and completely eliminated from the plasma after 60 min. There were no significant differences in the number of lymph nodes detected by MHI and radioactive colloid. Only one patient with lymph node macrometastases had no SLN detected by either the radioactive colloid or the MHI.

Conclusions

At a dose of up to 2.0 mL, MHI was well tolerated and safe for conducting SLN biopsies in patients with breast cancer. Although there was a case with blue discoloration of the local skin over the injection site after the operation, and remained for a short period of time, but the overall safety was acceptable. Here, we approached a novel SLN tracing slant; however, more investigations of MHI should be performed for further evaluations. (Chinadrugtrials.org.cn number: CXHL1301201, Date of registration: October 12, 2015.).