The clinical use of indocyanine green as a near-infrared fluorescent contrast agent for image-guided oncologic surgery

Indocyanine green uptake by human tumor and non‑tumor cell lines and tissue

Indocyanine green (ICG) is a potential promising dye for a better intraoperative tumor border definition and an improved patient outcome by potentially improving tumor border visualization compared with traditional white light guided surgery. Here, the cellular uptake of ICG in human squamous cell carcinoma (SCC026) and immortalized non-cancer skin (HaCaT) cell lines was evaluated to study the tumor-specific cellular uptake of ICG. The spatial distribution of ICG inside tumor tissue was investigated in tissue sections of head and neck squamous cell carcinoma at a microscopic level. ICG uptake and internalization was observed in living cells after 2.5 h and in the nucleus after 24 h. In dead cells, higher and faster uptake was observed. In the tissue sections, higher ICG signal intensity could be detected in connective tissue and surrounding clusters and blood vessels. In conclusion, no distinct ICG uptake by tumor cells was detected in cancer cell lines and tumor tissue. ICG localization in certain regions of tumor tissue appears to be a result of enhanced tissue permeability and retention, but not specific to tumor cells.

Shortwave Infrared Imaging of a Quantum Dot-Based Magnetic Guidewire Toward Non-Fluoroscopic Peripheral Vascular Interventions

Peripheral vascular interventions (PVIs) offer several benefits to patients with lower extremity arterial diseases, including reduced pain, simpler anesthesia, and shorter recovery time, compared to open surgery. However, to monitor the endovascular tools inside the body, PVIs are conducted under X-ray fluoroscopy, which poses serious long-term health risks to physicians and patients. Shortwave infrared (SWIR) imaging of quantum dots (QDs) has shown great potential in bioimaging due to the non-ionizing penetration of SWIR light through tissues. In this paper, a QD-based magnetic guidewire and its system is introduced that allows X-ray-free detection under SWIR imaging and precise steering via magnetic manipulation. The QD magnetic guidewire contains a flexible silicone tube encapsulating a QD polydimethylsiloxane (PDMS) composite, where HgCdSe/HgS/CdS/CdZnS/ZnS/SiO2 core/multi-shell QDs are dispersed in the PDMS matrix for SWIR imaging upon near-infrared excitation, as well as a permanent magnet for magnetic steering. The SWIR penetration of the QD magnetic guidewire is investigated within an artificial tissue model (1% Intralipid) and explore the potential for non-fluoroscopic PVIs within a vascular phantom model. The QD magnetic guidewire is biocompatible in its entirety, with excellent resistance to photobleaching and chemical alteration, which is a promising sign for its future clinical implementation.

Rational construction of CQDs-based targeted multifunctional nanoplatform for synergistic chemo-photothermal tumor therapy

Photothermal therapy combined with chemotherapy has shown great promise in the treatment of cancer. In this synergistic system, a safe, stable, and efficient photothermal agent is desired. Herein, an effective photothermal agent, carbon quantum dots (CQDs), was initially synthesized and then rationally constructed a folic acid (FA)-targeted photothermal multifunctional nanoplatform by encapsulating CQDs and the anticancer drug doxorubicin (DOX) in the liposomes. Indocyanine green (ICG), a near infrared (NIR) photothermal agent, approved by the U.S. Food and Drug Administration, was embedded in the bilayer membrane to further enhance the photothermal effects and facilitate the rapid cleavage of liposomes for drug release. Triggered by the NIR laser, this engineered photothermal multifunctional nanoplatform, not only exhibited an excellent performance with the photothermal conversion efficiency of up to 47.14%, but also achieved controlled release of the payloads. In vitro, and in vivo experiments demonstrated that the photothermal multifunctional nanoplatform had excellent biocompatibility, enhanced tumor-specific targeting, stimuli-responsive drug release, effective cancer cell killing and tumor suppression through multi-modal synergistic therapy. The successful construction of this NIR light-triggered targeted photothermal multifunctional nanoplatform will provide a promising strategy for the design and development of synergistic chemo-photothermal combination therapy and improve the therapeutic efficacy of cancer treatment.

Transcutaneous sentinel lymph node detection in skin melanoma with near-infrared fluorescence imaging using indocyanine green

The aim of the study is to assess whether indocyanine green (ICG) fluorescence can replace technetium in the preoperative detection of sentinel lymph nodes (SLN) from cutaneous melanoma. The current golden standard for SLN detection is the radioisotope technetium. A promising alternative is fluorescence imaging (FLI) using ICG. In this study, we enrolled patients undergoing sentinel lymph node biopsy (SLNB) for skin melanoma at the Erasmus Medical Center between November 2022 and July 2023. The SLNB procedure was performed as a standard of care. After general anesthesia, ICG was injected intradermally around the primary tumor site. Both the patient and the surgeon were not blinded for the location of the SLN. FLI was performed before incision, in vivo after incision, and ex vivo. Fluorescent SLNs were confirmed using the gamma probe in all cases. Thirty-two patients were included in this study, and a total of 39 SLNs were harvested. The transcutaneous detection rate of ICG was 21.9%. The combined ex vivo ICG fluorescence and technetium uptake was 94.9%. One SLN contained only ICG (2.6%) and one SLN contained only technetium-uptake (2.6%). FLI using ICG resulted in a relatively low transcutaneous detection, which means that exclusive use of this technique in its present form is not feasible. However, we did find a high accumulation of ICG in the SLN, indicating the potential of ICG in combination with other imaging techniques.

Validation of a semi-quantitative scoring system and workflow for analysis of fluorescence quantification in companion animals

Significance

Many commercially available near-infrared (NIR) fluorescence imaging systems lack algorithms for real-time quantifiable fluorescence data. Creation of a workflow for clinical assessment and post hoc analysis may provide clinical researchers with a method for intraoperative fluorescence quantification to improve objective outcome measures.

Aim

Scoring systems and verified image analysis are employed to determine the amount and intensity of fluorescence within surgical specimens both intra and postoperatively.

Approach

Lymph nodes from canine cancer patients were obtained during lymph node extirpation following peritumoral injection of indocyanine green (ICG). First, a semi-quantitative assessment of surface fluorescence was evaluated. Images obtained with a NIR exoscope were analysed to determine fluorescence thresholds and measure fluorescence amount and intensity.

Results

Post hoc fluorescence quantification (threshold of Hue = 165-180, Intensity = 30-255) displayed strong agreement with semi-quantitative scoring (k = 0.9734, p < 0.0001). Fluorescence intensity with either threshold of 35-255 or 45-255 were significant predictors of fluorescence and had high sensitivity and specificity (p < 0.05). Fluorescence intensity and quantification had a strong association (p < 0.001).

Conclusion

The validation of the semi-quantitative scoring system by image analysis provides a method for objective in situ observation of tissue fluorescence. The utilization of thresholding for ICG fluorescence intensity allows post hoc quantification of fluorescence when not built into the imaging system.

Treatment of Aphthous Ulcers with Photodynamic Therapy: A Randomized Controlled Clinical Study

BACKGROUND

This study aims to assess whether photodynamic therapy (PDT) offers a clinically effective alternative for treating oral aphthous ulcers, contributing to the ongoing quest for methods to expedite their treatment process amidst the limited understanding of their etiology.

MATERIALS AND METHOD

The study involved thirty volunteers with aphthous ulcers, split equally between a control group and a PDT group. Patients in the PDT group received laser treatment using Indocyanine green upon admission, while the control group received no intervention. Lesion diameter was measured at presentation and on the 3rd, 5th, and 7th days for all patients, with wound healing assessed on the 7th day. Additionally, pain levels were evaluated using the Visual Analog Scale (VAS) preoperatively and on the 1st, 3rd, 5th, and 7th days for the PDT group, and on the corresponding days for the control group.

RESULTS

Lesion diameters in the PDT group showed a significant reduction over time (p=0.001), particularly from preoperative to final measurements. The control group also exhibited a decrease, albeit slower (p=0.001). The 7th-day healing scores favored the PDT group significantly (p=0.012). VAS scores in the PDT group decreased significantly over time (p=0.001), indicating pain reduction. A similar trend was observed in the control group, albeit slower. Between-group differences in healing data and pain data were statistically significant.

CONCLUSION

PDT proves effective in reducing aphthous ulcer diameters and pain intensity, facilitating faster healing than the control group. These results advocate for PDT as a viable treatment option for aphthous lesions.

Advancing DIEP Flap Monitoring with Optical Imaging Techniques: A Narrative Review

OBJECTIVES

This review aims to explore recent advancements in optical imaging techniques for monitoring the viability of Deep Inferior Epigastric Perforator (DIEP) flap reconstruction. The objectives include highlighting the principles, applications, and clinical utility of optical imaging modalities such as near-infrared spectroscopy (NIRS), indocyanine green (ICG) fluorescence angiography, laser speckle contrast imaging (LSCI), hyperspectral imaging (HSI), dynamic infrared thermography (DIRT), and short-wave infrared thermography (SWIR) in assessing tissue perfusion and oxygenation. Additionally, this review aims to discuss the potential of these techniques in enhancing surgical outcomes by enabling timely intervention in cases of compromised flap perfusion.

MATERIALS AND METHODS

A comprehensive literature review was conducted to identify studies focusing on optical imaging techniques for monitoring DIEP flap viability. We searched PubMed, MEDLINE, and relevant databases, including Google Scholar, Web of Science, Scopus, PsycINFO, IEEE Xplore, and ProQuest Dissertations & Theses, among others, using specific keywords related to optical imaging, DIEP flap reconstruction, tissue perfusion, and surgical outcomes. This extensive search ensured we gathered comprehensive data for our analysis. Articles discussing the principles, applications, and clinical use of NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR in DIEP flap monitoring were selected for inclusion. Data regarding the techniques' effectiveness, advantages, limitations, and potential impact on surgical decision-making were extracted and synthesized.

RESULTS

Optical imaging modalities, including NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR offer a non- or minimal-invasive, real-time assessment of tissue perfusion and oxygenation in DIEP flap reconstruction. These techniques provide objective and quantitative data, enabling surgeons to monitor flap viability accurately. Studies have demonstrated the effectiveness of optical imaging in detecting compromised perfusion and facilitating timely intervention, thereby reducing the risk of flap complications such as partial or total loss. Furthermore, optical imaging modalities have shown promise in improving surgical outcomes by guiding intraoperative decision-making and optimizing patient care.

CONCLUSIONS

Recent advancements in optical imaging techniques present valuable tools for monitoring the viability of DIEP flap reconstruction. NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR offer a non- or minimal-invasive, real-time assessment of tissue perfusion and oxygenation, enabling accurate evaluation of flap viability. These modalities have the potential to enhance surgical outcomes by facilitating timely intervention in cases of compromised perfusion, thereby reducing the risk of flap complications. Incorporating optical imaging into clinical practice can provide surgeons with objective and quantitative data, assisting in informed decision-making for optimal patient care in DIEP flap reconstruction surgeries.

Fluorescence Intensity between Standard versus Diluted Indocyanine Green to Evaluate Flap Perfusion in Rats

The ideal dose for indocyanine green (ICG) has not been established yet, although 5 mg per mL is widely accepted for free flap evaluation. Due to its high price and rarity in developing countries, this preliminary study aimed to find the lowest concentration of ICG without reducing the fluorescence quality read by near-infrared camera in animal models. An experimental study was conducted on 25 Wistar rats divided into five groups based on the injected ICG, which was in 5 mg per mL, 3.75 mg per mL, 2.5 mg per mL, 1.25 mg per mL, and 0.5 mg per mL concentrations. The epigastric flap was elevated and confirmed to be vital on the fifth day. Upon confirmation, bolus IV injection of ICG was given via the tail, and the flap was read using near-infrared camera. The 25 different videos are randomized and rated individually in a blind manner by five microsurgeons, chosen beforehand. The videos are evaluated with a scoring system ranging from 0 to 4, assessing fluorescence visibility and flap vasculature. Nonetheless, the intraclass correlation coefficient is 0.779. There was no difference between standard and diluted ICG concentrations to evaluate flap perfusion. The 2.5 mg per mL concentration of ICG was the most favorable. This finding is not clinically relevant for application in human subjects yet. However, this study shows promising results for further usage of ICG in daily practice at a lower cost.

Infrared Fluorescence-guided Surgery for Tumor and Metastatic Lymph Node Detection in Head and Neck Cancer

In patients with head and neck cancer (HNC), surgical removal of cancerous tissue presents the best overall survival rate. However, failure to obtain negative margins during resection has remained a steady concern over the past 3 decades. The need for improved tumor removal and margin assessment presents an ongoing concern for the field. While near-infrared agents have long been used in imaging, investigation of these agents for use in HNC imaging has dramatically expanded in the past decade. Targeted tracers for use in primary and metastatic lymph node detection are of particular interest, with panitumumab-IRDye800 as a major candidate in current studies. This review aims to provide an overview of intraoperative near-infrared fluorescence-guided surgery techniques used in the clinical detection of malignant tissue and sentinel lymph nodes in HNC, highlighting current applications, limitations, and future directions for use of this technology within the field. Keywords: Molecular Imaging-Cancer, Fluorescence © RSNA, 2024.

Effect of transbronchial or intravenous administration of indocyanine green on resection margins during near-infrared-guided segmentectomy: a review

For early-stage non-small cell lung cancer, surgical resection remains the best treatment option. Currently, sublobar resection, including segmentectomy, is recommended in these cases, as it provides a better quality of life with the same oncological outcomes; however, is requires adequate resection margins. Accurate preoperative planning and proper identification of the intersegmental planes during thoracic surgery are crucial for ensuring precise surgical management and adequate resection margins. Three dimensional computed tomography reconstruction and near-infrared-guided intersegmental plane identification can greatly facilitate the surgical procedures. Three-dimensional computed tomography reconstruction can simulate both the resection and resection margins. Indocyanine green is one of the most frequently used and affordable fluorophores. There are two ways to identify the intersegmental planes using indocyanine green: intravenous and transbronchial administration. Intravenous application is simple; however, its effectiveness may be affected by underlying lung disease, and it requires the isolation of segmental structures before administration. Transbronchial use requires appropriate bronchoscopic skills and preoperative planning; however, it also allows for delineation deep in the parenchyma and can be used for complex segmentectomies. Both methods can be used to ensure adequate resection margins and, therefore, achieve the correct oncological radicality of the surgical procedure. Here, we summarise these applications and provide an overview of their different possibilities.

Indocyanine green in gynecologic surgery: Where do we stand? A literature review and meta-analysis

The main objective of this study was to review and perform a meta-analysis of current literature on the use of indocyanine green for sentinel lymph node detection in pelvic gynecologic cancer. We included all studies focusing on indications and procedures associated with the use of ICG in gynecologic surgery and available on the Medline and Pubmed database. For the meta-analysis, random effect models were used for estimation of the 95 % detection rate and 95 % confidence interval, and stratified analyses by cancer type, concentration and localization of injection were performed. A total of 147 articles were included, of which 91 were studied in a meta-analysis. Results concerning detection rate by indocyanine green injection site were found to be 95.1 % and 97.3 % respectively for intracervical injection in 2 or 4 quadrants, and 77.0 % and 94.8 % for hysteroscopic and intradermal injection respectively. Results concerning detection rate by cancer type were 95.8 %, 95.2 %, 94.7 % and 95.7 % respectively for cervical, endometrial, vulvar and endometrial/cervical cancers. Finally, the results concerning detection rate by indocyanine green concentration were 91.2 %, 95.7 %, 96.7 % and 97.7 % for concentrations of <1.25 mg/ml, 1.25 mg/ml, 2.5 mg/ml and 5 mg/ml respectively. In conclusion, indocyanine green is shown to allow highlighting of sentinel lymph nodes with good reliability with an overall indocyanine green detection rate of 95.5 %. Our literature review revealed that indocyanine green feasibility has also been demonstrated in several surgical contexts, notably for reconstructive surgery and detection of endometriosis.

Canine preclinical safety evaluation of a multimodal nanoparticle agent (Nanotrast-CF800) for image-guided cancer surgery

Surgical oncology often requires the use of contrast-enhanced cross-sectional imaging preoperatively to characterize solitary tumours and identify sentinel lymph nodes. Intraoperative optical guidance can effectively aid tissue-sparing tumour excision and locate sentinel lymph nodes. Nanotrast-CF800 (CF800) is a novel dual-modality contrast agent, which co-encapsulates iohexol and indocyanine green (ICG) within a liposomal nanoparticle. It was developed for preoperative and intraoperative imaging of solitary tumours and sentinel lymph node mapping and its efficacy has been demonstrated in preclinical animal models (Zheng et al. 2015). The objective of this study is to evaluate the safety profile of CF800 following intravenous administration in healthy dogs. Six research dogs were randomized into two groups. Group 1 received a low dose (1 mL/kg) and group 2 received a high dose (5 mL/kg). Dogs were placed under general anesthesia and a continuous rate infusion of CF800 was administered based on group allocation. Physiologic parameters including heart rate, respiratory rate, direct arterial blood pressure, cardiac output, and temperature were measured at set time points. Plasma concentrations of iohexol, ICG, and histamine were measured at set time points. Dogs underwent whole body computed tomography scans pre-injection, 2-, and 7-days post-injection (p.i.). Contrast enhancement was measured in select organ systems and great vessels at each time point. There were no significant changes in physiologic parameters following IV infusion of CF800 in all dogs. Plasma iohexol and ICG concentrations peaked at 1 day p.i., while histamine concentrations peaked at 30 minutes p.i. Significant contrast enhancement was noted within the liver, heart, aorta, and caudal vena cava on day 2 p.i., which was significantly different compared to baseline. Prolonged contrast retention within the liver was identified. Intravenous administration of CF800 was safe to use in healthy dogs with no significant systemic adverse effects.

"The Green Peace" How ICG can prevent complications in endometriosis surgery?

This literature review summarises the investigation into using Indocyanine Green (ICG) in the surgical management of endometriosis, focusing mainly on its application in Deep Endometriosis (DE). The study reviews the development, fluorescence characteristics, and clinical usage of ICG in enhancing the precision of identifying endometrial lesions during surgery. Emphasizing the technology's contribution to improved lesion visualisation, the paper discusses how ICG facilitates increased diagnostic accuracy, potentially reducing recurrence rates and the necessity for subsequent interventions. Additionally, it explores ICG's role in minimizing the risk of iatrogenic injuries, especially in ureteral endometriosis, and its utility in surgical decision-making for rectosigmoid endometriosis by evaluating bowel perfusion. Conclusively, while acknowledging the clear benefits of ICG integration in endometriosis surgical procedures, the abstract calls for more extensive research to validate its efficacy and cost-efficiency in the broader context of endometriosis treatment.

eTFC-01: a dual-labeled chelate-bridged tracer for SSTR2-positive tumors

BACKGROUND

Integrating radioactive and optical imaging techniques can facilitate the prognosis and surgical guidance for cancer patients. Using a single dual-labeled tracer ensures consistency in both imaging modalities. However, developing such molecule is challenging due to the need to preserve the biochemical properties of the tracer while introducing bulky labeling moieties. In our study, we designed a trifunctional chelate that facilitates the coupling of the targeting vector and fluorescent dye at opposite sites to avoid undesired steric hindrance effects. The synthesis of the trifunctional chelate N3-Py-DOTAGA-(tBu)3 (7) involved a five-step synthetic route, followed by conjugation to the linear peptidyl-resin 8 through solid-phase synthesis. After deprotection and cyclization, the near-infrared fluorescent dye sulfo-Cy.5 was introduced using copper free click chemistry, resulting in eTFC-01. Subsequently, eTFC-01 was labeled with [111In]InCl3. In vitro assessments of eTFC-01 binding, uptake, and internalization were conducted in SSTR2-transfected U2OS cells. Ex-vivo biodistribution and fluorescence imaging were performed in H69-tumor bearing mice.

RESULTS

eTFC-01 demonstrated a two-fold higher IC50 value for SSTR2 compared to the gold standard DOTA-TATE. Labeling of eTFC-01 with [111In]InCl3 gave a high radiochemical yield and purity. The uptake of [111In]In-eTFC-01 in U2OS.SSTR2 cells was two-fold lower than the uptake of [111In]In-DOTA-TATE, consistent with the binding affinity. Tumor uptake in H69-xenografted mice was lower for [111In]In-eTFC-01 at all-time points compared to [111In]In-DOTA-TATE. Prolonged blood circulation led to increased accumulation of [111In]In-eTFC-01 in highly vascularized tissues, such as lungs, skin, and heart. Fluorescence measurements in different organs correlated with the radioactive signal distribution.

CONCLUSION

The successful synthesis and coupling of the trifunctional chelate to the peptide and fluorescent dye support the potential of this synthetic approach to generate dual labeled tracers. While promising in vitro, the in vivo results obtained with [111In]In-eTFC-01 suggest the need for adjustments to enhance tracer distribution.

Bronchoscopic Lung Volume Reduction as the Treatment of Choice versus Robotic-Assisted Lung Volume Reduction Surgery in Similar Patients with Emphysema - An Initial Experience of the Benefits and Complications

Objective

There is an assumption that because EBLVR requires less use of hospital resources, offsetting the higher cost of endobronchial valves, it should therefore be the treatment of choice wherever possible. We have tested this hypothesis in a retrospective analysis of the two in similar groups of patients.

Methods

In a 4-year experience, we performed 177 consecutive LVR procedures: 83 patients underwent Robot Assisted Thoracoscopic (RATS) LVRS and 94 EBLVR. EBLVR was intentionally precluded by evidence of incomplete fissure integrity or intra-operative assessment of collateral ventilation. Unilateral RATS LVRS was performed in these cases together with those with unsuitable targets for EBLVR.

Results

EBLVR was uncomplicated in 37 (39%) cases; complicated by post-procedure spontaneous pneumothorax (SP) in 28(30%) and required revision in 29 (31%). In the LVRS group, 7 (8%) patients were readmitted with treatment-related complications, but no revisional procedure was needed. When compared with uncomplicated EBLVR, LVRS had a significantly longer operating time: 85 (14-82) vs 40 (15-151) minutes (p<0.001) and hospital stay: 7.5 (2-80) vs 2 (1-14) days (p<0.01). However, LVRS had a similar total operating time to both EBLVR requiring revision: 78 (38-292) minutes and hospital stay to EBLVR complicated by pneumothorax of 11.5 (6.5-24.25) days. Use of critical care was significantly longer in RATS group, and it was also significantly longer in EBV with SP group than in uncomplicated EBV group.

Conclusion

Endobronchial LVR does use less hospital resources than RATS LVRS in comparable groups if the recovery is uncomplicated. However, this advantage is lost if one includes the resources needed for the treatment of complications and revisional procedures. Any decision to favour EBLVR over LVRS should not be based on the assumption of a smoother, faster perioperative course.

The use of diagnostic complex robotic-assisted segmentectomy in the management of incidental and screen-detected pulmonary nodules

OBJECTIVES

Robotic-assisted thoracoscopic surgery (RATS) facilitates complex pulmonary segmentectomy which offers one-stage diagnostic and therapeutic management of small pulmonary nodules. We aimed to explore the potential advantages of a faster, simplified pathway and earlier diagnosis against the disadvantages of unnecessary morbidity in benign cases.

METHODS

In an observational study, patients with small, solitary pulmonary nodules deemed suspicious of malignancy by a multidisciplinary team were offered surgery without a pre or intraoperative biopsy. We report our initial experience with RATS complex segmentectomy (using >1 parenchymal staple line) to preserve as much functioning lung tissue as possible.

RESULTS

Over a 4-year period, 245 RATS complex segmentectomies were performed; 140 right: 105 left. A median of 2 (1-4) segments was removed. There was no in-hospital mortality and no requirement for postoperative ventilation. Complications were reported in 63 (25.7%) cases, of which 36 (57.1%) were hospital-acquired pneumonia. A malignant diagnosis was found in 198 (81%) patients and a benign diagnosis in 47 (19%). The malignant diagnoses included: adenocarcinoma in 136, squamous carcinoma in 31 and carcinoid tumour in 15. The most frequent benign diagnosis was granulomatous inflammation in 18 cases.

CONCLUSIONS

RATS complex segmentectomy offers a precise, safe and effective one-stop therapeutic biopsy in incidental and screen-detected pulmonary nodules.

Five near-infrared-emissive graphene quantum dots for multiplex bioimaging

Due to high tissue penetration depth and low autofluorescence backgrounds, near-infrared (NIR) fluorescence imaging has recently become an advantageous diagnostic technique used in a variety of fields. However, most of the NIR fluorophores do not have therapeutic delivery capabilities, exhibit low photostabilities, and raise toxicity concerns. To address these issues, we developed and tested five types of biocompatible graphene quantum dots (GQDs) exhibiting spectrally-separated fluorescence in the NIR range of 928-1053 nm with NIR excitation. Their optical properties in the NIR are attributed to either rare-earth metal dopants (Ho-NGQDs, Yb-NGQDs, Nd-NGQDs) or defect-states (nitrogen doped GQDS (NGQDs), reduced graphene oxides) as verified by Hartree-Fock calculations. Moderate up to 1.34% quantum yields of these GQDs are well-compensated by their remarkable >4 h photostability. At the biocompatible concentrations of up to 0.5-2 mg ml-1 GQDs successfully internalize into HEK-293 cells and enable in vitro imaging in the visible and NIR. Tested all together in HEK-293 cells five GQD types enable simultaneous multiplex imaging in the NIR-I and NIR-II shown for the first time in this work for GQD platforms. Substantial photostability, spectrally-separated NIR emission, and high biocompatibility of five GQD types developed here suggest their promising potential in multianalyte testing and multiwavelength bioimaging of combination therapies.

The use of intravenous indocyanine green in minimally invasive segmental lung resections: a systematic review

Background

To identify intersegmental planes (ISPs) in video/robot-assisted thoracoscopic segmentectomies, indocyanine green (ICG) is commonly used. The aim of this systematic review is to evaluate the efficacy of intravenous ICG in the identification of ISP.

Methods

A systematic search was performed. Studies evaluating patients who underwent a video/robot-assisted thoracoscopic segmentectomy using intravenous ICG were included. The primary outcome measure was the frequency and percentage of patients in whom the ISP was adequately visualized. Secondary outcomes encompassed the ICG dose, time to visualization, time to maximum ICG visualization, time to disappearance of ICG effect and adverse reactions to ICG.

Results

Eighteen studies were included for systematic review, enrolling a total of 1,090 patients. Irrespective of the injected dose, intravenous ICG identified the ISP in 94% of the cases (range, 30-100%). Overall, there was a considerable amount of heterogeneity regarding the injected dose of ICG (range, 5-25 mg or 0.05-0.5 mg/kg). The mean time before first effect of ICG was visible ranged from 10 to 40 seconds. The mean total time of ICG visibility ranged from 90 to 140 seconds after a bolus injection and was 170 seconds after continuous infusion. No adverse reactions were reported.

Conclusions

After administration of intravenous ICG, visualization of the ISP is successful in up to 94% of cases, even after administration of a low dose (0.05 mg/kg) of ICG. The use of intravenous ICG is safe with no reported adverse effects in the immediate peri-operative period.

Visualization Methods for Uterine Sentinel Lymph Nodes in Early-Stage Endometrial Carcinoma: A Comparative Analysis

BACKGROUND

Sentinel lymph node (SLN) biopsy in early-stage endometrial cancer is recommended over systematic lymphadenectomy due to reduced morbidity and comparable detection rates. The main objective of this study was to compare the overall and bilateral detection rates of SLN in early-stage endometrial cancer using three techniques.

METHODS

a prospective cohort study was designed to detect the difference in SLN detection rate in three cohorts: Indocyanine green (ICG), methylene blue (MB), and tracer combination (ICG + MB). Mapping characteristics, detection rate, number of SLNs, and positive SLNs of the three cohorts were compared.

RESULTS

A total of 99 patients were enrolled. A total of 109 SLN sites with 164 lymph nodes were detected. No differences were found between the three cohorts in terms of age, BMI, tumor diameter, or other histologic characteristics. The overall SLN detection rate (DR) was 54.3% in the MB group, 72.7% in ICG, and 80.6% in the ICG-MB group. Bilateral DR was 22.9%, 39.4%, and 54.8% in groups, respectively, with the MB method yielding significantly inferior results.

CONCLUSIONS

The ICG-MB group demonstrated superior overall and bilateral detection rates, but a significant difference was found only in the MB cohort. Combining tracer agents can enhance the accuracy of SLN identification in initial-stage endometrial cancer without additional risk to the patient.

Theranostics: a multifaceted approach utilizing nano-biomaterials

Biomaterials play a vital role in targeting therapeutics. Over the years, several biomaterials have gained wide attention in the treatment and diagnosis of diseases. Scientists are trying to make more personalized treatments for different diseases, as well as discovering novel single agents that can be used for prognosis, medication administration, and keeping track of how a treatment works. Theranostics based on nano-biomaterials have higher sensitivity and specificity for disease management than conventional techniques. This review provides a concise overview of various biomaterials, including carbon-based materials like fullerenes, graphene, carbon nanotubes (CNTs), and carbon nanofibers, and their involvement in theranostics of different diseases. In addition, the involvement of imaging techniques for theranostics applications was overviewed. Theranostics is an emerging strategy that has great potential for enhancing the accuracy and efficacy of medicinal interventions. Despite the presence of obstacles such as disease heterogeneity, toxicity, reproducibility, uniformity, upscaling production, and regulatory hurdles, the field of medical research and development has great promise due to its ability to provide patients with personalised care, facilitate early identification, and enable focused treatment.

First-in-human Evaluation of a Prostate-specific Membrane Antigen-targeted Near-infrared Fluorescent Small Molecule for Fluorescence-based Identification of Prostate Cancer in Patients with High-risk Prostate Cancer Undergoing Robotic-assisted Prostatectomy

BACKGROUND

Men with high-risk prostate cancer undergoing surgery likely recur due to failure to completely excise regional and/or local disease.

OBJECTIVE

The first-in-human evaluation of safety, pharmacokinetics, and exploratory efficacy of IS-002, a novel near-infrared prostate-specific membrane antigen (PSMA)-targeted fluorescence imaging agent, designed for intraoperative prostate cancer visualization.

DESIGN, SETTING, AND PARTICIPANTS

A phase 1, single-center, dose-escalation study was conducted in 24 men with high-risk prostate cancer scheduled for robotic-assisted radical prostatectomy with (extended) pelvic lymph node dissection using the da Vinci surgical system.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Adverse events (AEs), vital signs, complete blood count, complete metabolic panel, urinalysis, and electrocardiogram were assessed over a 14-d period and compared with baseline. The pharmacokinetic profile of IS-002 was determined. Diagnostic accuracy was assessed for exploratory efficacy.

RESULTS AND LIMITATIONS

AEs predominantly included discoloration of urine (n = 22/24; expected, related, grade 1). There were no grade ≥2 AEs. IS-002 Cmax and area under the curve increased with increasing dose. Plasma concentrations declined rapidly in a biphasic manner, with the median terminal half-lives ranging from 5.0 to 7.6 h, independent of dose and renal function. At 25 μg/kg, the exploratory efficacy readouts for the negative and positive predictive values were, 97% and 45% for lymph nodes, and 100% and 80% for residual/locoregional disease detection, respectively.

CONCLUSIONS

IS-002 is safe and well tolerated, and has the potential to enable intraoperative tumor detection that could not be identified using standard imaging.

PATIENT SUMMARY

IS-002 is a new imaging agent that specifically targets the prostate-specific membrane antigen receptor. In this study, we tested IS-002 for the first time in men with high-risk prostate cancer undergoing surgery and found that IS-002 is safe, is cleared from the body quickly, and potentially allows identification of prostate cancer in areas that would not be identified by conventional white light imaging.

Comparison of indocyanine green-near-infrared fluorescence guided and traditional mediastinal lymphadenectomy during radical esophagectomy: A randomized controlled trial

BACKGROUND

The extent of lymph node dissection during radical esophagectomy remains a controversial topic. Thus, this study mainly aimed to explore the location of sentinel lymph nodes in esophageal squamous cell carcinoma and the application value of the indocyanine green-near-infrared fluorescence system in lymphadenectomy.

METHODS

This randomized controlled clinical trial (ClinicalTrials.gov, NCT04615806) included 42 participants without neoadjuvant therapy who were lymph node negative based on positron emission tomography/computed tomography findings. Traditional esophagectomy with indocyanine green-near-infrared fluorescence imaging was performed after injecting 0.5 mL indocyanine green (1.25 mg/mL) into the esophageal submucosa in the 4 peritumoral quadrants. The primary endpoint was to determine the location of the sentinel lymph node in esophageal squamous cell carcinoma based on postoperative pathologic reports.

RESULTS

A total of 40 patients, with 20 in each group, were included in the final analysis. In the indocyanine green group, indocyanine green-near-infrared fluorescence imaging was successful in all subjects. Seven cases (cases 2, 3, 9, 11, 17, 18, and 20) in the indocyanine green group exhibited lymph node metastases, all of which were near-infrared positive. The detection rate, positive predictive value, negative predictive value, sensitivity, and specificity were 100% (20 of 20 cases), 8.7% (13/150), 100% (265/265), 100% (13/13), and 65.9% (265/402), respectively. All near-infrared-negative lymph nodes were nonmetastatic lymph nodes. In addition, the number of mediastinal lymph nodes resected in the indocyanine green group was significantly higher than in the non-indocyanine green group.

CONCLUSION

Indocyanine green-near-infrared might be an important and promising technique in predicting sentinel lymph nodes of esophageal squamous cell carcinoma and could significantly improve the detection rate of lymph nodes of esophageal squamous cell carcinoma.

Factors Affecting the Efficiency of Near-Infrared Indocyanine Green (NIR/ICG) in Lymphatic Mapping for Colorectal Cancer: A Systematic Review

As laparoscopy gained global popularity in oncologic surgery, the challenge of detecting lymph nodes spurred researchers to explore innovative techniques and approach the situation from a fresh perspective. While many proposed methods have faded into obscurity, the utilization of indocyanine green (ICG) in the surgical treatment of oncologic patients has continued to advance. The immense potential of this dye is widely acknowledged, yet its full extent and limitations in lymphatic mapping for colorectal cancer remain to be precisely determined. This article aims to assess the magnitude of its potential and explore the constraints based on insights from clinical studies published by pioneering researchers. A systematic review of the existing literature, comprising articles in English, was conducted using the Scopus, PubMed, and Springer Link databases. The search employed keywords such as "colorectal cancer" AND/OR "indocyanine green," "fluorescence" AND/OR "lymphatic mapping" AND/OR "lymph nodes." Initially identifying 129 articles, the application of selection criteria narrowed down the pool to 10 articles, which served as the primary sources of data for our review. Despite the absence of a standardized protocol for the application of ICG in colorectal cancer, particularly in the context of lymphatic mapping, the detection rates have exhibited considerable variation across studies. Nevertheless, all authors unanimously regarded this technique as beneficial and promising. Additionally, it is advocated as an adjunctive tool to enhance the accuracy of cancer staging. Near-infrared (NIR)-enhanced surgery holds the promise of transforming the landscape of oncologic surgery, emerging as a valuable tool for surgeons. However, the absence of a standardized technique and the subjective nature of result assessment impose limitations on the potential of this method. Consequently, it can be inferred that the establishment of a universally accepted protocol, encompassing parameters such as dose, concentration, technique, and site of administration of ICG, along with the optimal time needed for fluorescence visualization, would enhance the outcomes. Emphasizing the accurate selection of patients is crucial to prevent the occurrence of false-negative results.

Gene and Photothermal Combination Therapy: Principle, Materials, and Amplified Anticancer Intervention

Gene therapy (GT) and photothermal therapy (PTT) have emerged as promising alternatives to chemotherapy and radiotherapy for cancer treatment, offering noninvasiveness and reduced side effects. However, their efficacy as standalone treatments is limited. GT exhibits slow response rates, while PTT is confined to local tumor ablation. The convergence of GT and PTT, known as GT-PTT, facilitated by photothermal gene nanocarriers, has attracted considerable attention across various disciplines. In this integrated approach, GT reciprocates PTT by sensitizing cellular response to heat, while PTT benefits GT by improving gene translocation, unpacking, and expression. Consequently, this integration presents a unique opportunity for cancer therapy with rapid response and improved effectiveness. Extensive efforts over the past few years have been dedicated to the development of GT-PTT, resulting in notable achievements and rapid progress from the laboratory to potential clinical applications. This comprehensive review outlines recent advances in GT-PTT, including synergistic mechanisms, material systems, imaging-guided therapy, and anticancer applications. It also explores the challenges and future prospects in this nascent field. By presenting innovative ideas and insights into the implementation of GT-PTT for enhanced cancer therapy, this review aims to inspire further progress in this promising area of research.

OSATS scoring confirms ICG enhancement of performance in laparoscopic radical gastrectomy: a post-hoc analysis of a randomized controlled trial

BACKGROUND

Indocyanine green (ICG) fluorescence imaging is effective in increasing the number of lymph node dissections during laparoscopic radical gastrectomy; however, no studies have attempted to explain this phenomenon.

METHODS

This study utilized the data from a previous randomized controlled trial (FUGES-012 study) investigating ICG-guided laparoscopic radical gastrectomy performed between November 2018 and July 2019. The Objective Structured Assessments of Technical Skills (OSATS) scoring system was used to grade videos from the ICG and non-ICG groups. Patients with an OSATS score greater than 29 were classified as the high-OSATS population, while those with an OSATS score less than or equal to 29 were classified as the low-OSATS population.

RESULTS

A total of 258 patients were included in the modified intention-to-treat analysis: 129 in the ICG group and 129 in the non-ICG group. The OSATS score of the ICG group was higher than that of the non-ICG group (29.6±2.6 vs. 26.6±3.6; P <0.001). The ICG group underwent a significantly higher mean total number of lymph node dissections than the non-ICG group (50.5±15.9 vs. 42.0±10.3; adjusted P <0.001). The group assigned to ICG use, better OSATS (high-OSATS) scores were observed, which correlated with greater D2 lymph node retrieval (54.1±15.0 vs. 47.2±8.7; adjusted P =0.039). Finally, the ICG group had a lower rate of lymph node noncompliance than that of the non-ICG group (31.8 vs. 57.4%; P <0.001).

CONCLUSIONS

By applying the ICG fluorescence navigation technique, better OSATS scores were observed, which correlated with greater lymph node retrieval and a lower lymph node noncompliance rate, as recommended for individualized laparoscopic radical gastrectomy.

Fluorescence lifetime of injected indocyanine green as a universal marker of solid tumours in patients

The surgical resection of solid tumours can be enhanced by fluorescence-guided imaging. However, variable tumour uptake and incomplete clearance of fluorescent dyes reduces the accuracy of distinguishing tumour from normal tissue via conventional fluorescence intensity-based imaging. Here we show that, after systemic injection of the near-infrared dye indocyanine green in patients with various types of solid tumour, the fluorescence lifetime (FLT) of tumour tissue is longer than the FLT of non-cancerous tissue. This tumour-specific shift in FLT can be used to distinguish tumours from normal tissue with an accuracy of over 97% across tumour types, and can be visualized at the cellular level using microscopy and in larger specimens through wide-field imaging. Unlike fluorescence intensity, which depends on imaging-system parameters, tissue depth and the amount of dye taken up by tumours, FLT is a photophysical property that is largely independent of these factors. FLT imaging with indocyanine green may improve the accuracy of cancer surgeries.

Advancements in Intraoperative Near-Infrared Fluorescence Imaging for Accurate Tumor Resection: A Promising Technique for Improved Surgical Outcomes and Patient Survival

Clear surgical margins for solid tumor resection are essential for preventing cancer recurrence and improving overall patient survival. Complete resection of tumors is often limited by a surgeon's ability to accurately locate malignant tissues and differentiate them from healthy tissue. Therefore, techniques or imaging modalities are required that would ease the identification and resection of tumors by real-time intraoperative visualization of tumors. Although conventional imaging techniques such as positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI), or radiography play an essential role in preoperative diagnostics, these cannot be utilized in intraoperative tumor detection due to their large size, high cost, long imaging time, and lack of cancer specificity. The inception of several imaging techniques has paved the way to intraoperative tumor margin detection with a high degree of sensitivity and specificity. Particularly, molecular imaging using near-infrared fluorescence (NIRF) based nanoprobes provides superior imaging quality due to high signal-to-noise ratio, deep penetration to tissues, and low autofluorescence, enabling accurate tumor resection and improved survival rates. In this review, we discuss the recent developments in imaging technologies, specifically focusing on NIRF nanoprobes that aid in highly specific intraoperative surgeries with real-time recognition of tumor margins.

Current Advances in Nanotheranostics for Molecular Imaging and Therapy of Cardiovascular Disorders

Cardiovascular diseases (CVDs) refer to a collection of conditions characterized by abnormalities in the cardiovascular system. They are a global problem and one of the leading causes of mortality and disability. Nanotheranostics implies to the combination of diagnostic and therapeutic capabilities inside a single nanoscale platform that has allowed for significant advancement in cardiovascular diagnosis and therapy. These advancements are being developed to improve imaging capabilities, introduce personalized therapies, and boost cardiovascular disease patient treatment outcomes. Significant progress has been achieved in the integration of imaging and therapeutic capabilities within nanocarriers. In the case of cardiovascular disease, nanoparticles provide targeted delivery of therapeutics, genetic material, photothermal, and imaging agents. Directing and monitoring the movement of these therapeutic nanoparticles may be done with pinpoint accuracy by using imaging modalities such as cardiovascular magnetic resonance (CMR), computed tomography (CT), positron emission tomography (PET), photoacoustic/ultrasound, and fluorescence imaging. Recently, there has been an increasing demand of noninvasive for multimodal nanotheranostic platforms. In these platforms, various imaging technologies such as optical and magnetic resonance are integrated into a single nanoparticle. This platform helps in acquiring more accurate descriptions of cardiovascular diseases and provides clues for accurate diagnosis. Advances in surface functionalization methods have strengthened the potential application of nanotheranostics in cardiovascular diagnosis and therapy. In this Review, we have covered the potential impact of nanomedicine on CVDs. Additionally, we have discussed the recently developed various nanoparticles for CVDs imaging. Moreover, advancements in the CMR, CT, PET, ultrasound, and photoacoustic imaging for the CVDs have been discussed. We have limited our discussion to nanomaterials based clinical trials for CVDs and their patents.

Indocyanine green angiography in oncoplastic breast surgery, a prospective study

INTRODUCTION

The use of Indocyanine green angiography (ICG-A) in oncoplastic breast-conserving surgery (OBCS) has not yet been investigated. This prospective trial applied ICG-A in volume displacement and replacement OBCS to localize perforators and determine tissue supplied by the perforator. Furthermore, to investigate and correlate the intraoperative ICG-A to postoperative surgical site infection, skin necrosis, epidermolysis, and timely onset of adjuvant therapy.

METHODS

ICG-A was performed at three pre-set timepoints during surgery; after lumpectomy, upon dissection of possible perforators, and after wound closure. All patients were followed with clinical evaluations before surgery, 4 weeks, 4-6 months, and 12 months postoperatively.

RESULTS

Eleven patients were included: seven volume displacement and four volume replacement OBCS. ICG-A located the tissue supplied by the perforator and demonstrated sufficient perfusion in all cases. The ICG-A corresponded to the surgeons' clinical assessment. One patient developed a postoperative infection and seroma and was treated conservatively. No patients had postoperative necrosis, loss of reconstruction, or lymphedema of the arm. Edema of the breast occurred in four patients (36.4%). Scar assessments were significantly worse at 4-weeks and 4-6 months. The quality of life improved significantly during follow-up. Adjuvant treatment was administered timely in all cases.

CONCLUSION

ICG-A was feasible for OBCS in assessing intraoperative perfusion. Perfusion was sufficient in all patients and corresponded to the surgeon's clinical evaluation. No patients developed postoperative necrosis. Though edema of the breast occurred in 36.4%, a larger sample size is needed to investigate a possible correlation with ICG-A. Further studies, which includes patients requiring extensive tissue replacement challenging the borders of perfusion, are needed.

Enhanced stability and photothermal efficiency of Indocyanine Green J-aggregates by nanoformulation with Calix[4]arene for photothermal therapy of cancers

Photothermal therapy (PTT) is a method of growing attention, owing to its controllable process, high efficiency and minimal side effect. Indocyanine Green (ICG) is as Food and Drug Administration (FDA) approved agent that stands on the frontline of further developments of PTT toward clinics. However, the applicability of ICG-mediated PTT is limited by the rapid in vivo clearance and photo-degradation of ICG. To improve those parameters, nanosized ICG-loaded nanoparticles (ICG-J/CX) were fabricated in this study by co-assembly of anionic ICG J-aggregates (ICG-J) with cationic tetraguanidinium calix[4]arene (CX). This very simple approach produces ICG-J/CX with a well-defined nanometer range size and a close to neutral charge. The nanoparticles demonstrate high photothermal conversion efficiency (PCE) and dramatically improved photostability, as compared with ICG. The in vitro cellular uptake and cytotoxicity studies further demonstrated that the ICG-J/CX nanoparticles enhance uptake and photothermal efficiency in comparison with ICG or non-formulated ICG-J, overall demonstrating that ICG-J/CX mediated photothermal therapy have significant potential for attaining cancer treatment.

Global trends in indocyanine green fluorescence navigation in the field of gastric cancer: bibliometrics and knowledge atlas analysis

Background

Indocyanine green (ICG) fluorescence navigation can enhance the visualization of gastric cancer (GC) lesions, increase the lymph node detection rate, and reduce the incidence of anastomotic leakage in the treatment of GC. It thus holds considerable potential for application in GC clinical surgery and has attracted widespread research interest. The purpose of this study was to visualize the current topics and emerging trends in research regarding ICG in GC.

Methods

We searched the Web of Science Core Collection (WoSCC) for articles relevant to the use of ICG in GC. The resulting information was then analyzed from a bibliometric and knowledge graph analysis perspective using CiteSpace, Scimago Graphica, and R Studio so that the key trends and hot spots in research within this field could be identified and visualized.

Results

Ultimately, 1,385 papers from 58 countries or regions published from 1991 to 2022 were included in this study. The largest number of publications were from China, followed by Japan and the United States. High-yield institutions were concentrated in Asian countries, especially China. The top publication contributors were Shanghai Jiao Tong University. Li Y and Bang YJ ranked first among the top 10 most productive authors and top 10 most cocited authors, respectively. World Journal of Gastroenterology was the most productive academic journal on ICG in GC, while Cancer Research was the most commonly cocited journal. The keyword "indocyanine green" was among the top 5 keywords, and will likely remain a popular topic in future research. Furthermore, the emerging themes including surgery, biopsy, lymphadenectomy, dissection, and gastrectomy have attracted increasing attention.

Conclusions

Current research hotspots in this area focus on the clinical implementation of ICG in precision surgery for GC. Given the imaging tracer characteristics of ICG and its utility in GC surgery, the optimization and application of ICG-guided precision surgery techniques for GC will be a research hot spot going forward.

Indocyanine green dye and its application in gastrointestinal surgery: The future is bright green

Indocyanine green (ICG) is a water-soluble fluorescent dye that is minimally toxic and widely used in gastrointestinal surgery. ICG facilitates anatomical identification of structures (e.g., ureters), assessment of lymph nodes, biliary mapping, organ perfusion and anastomosis assessment, and aids in determining the adequacy of oncological margins. In addition, ICG can be conjugated to artificially created antibodies for tumour markers, such as carcinoembryonic antigen for colorectal, breast, lung, and gastric cancer, prostate-specific antigen for prostate cancer, and cancer antigen 125 for ovarian cancer. Although ICG has shown promising results, the optimization of patient factors, dye factors, equipment, and the method of assessing fluorescence intensity could further enhance its utility. This review summarizes the clinical application of ICG in gastrointestinal surgery and discusses the emergence of novel dyes such as ZW-800 and VM678 that have demonstrated appropriate pharmacokinetic properties and improved target-to-background ratios in animal studies. With the emergence of robotic technology and the increasing reporting of ICG utility, a comprehensive review of clinical application of ICG in gastrointestinal surgery is timely and this review serves that aim.

Percutaneous Computed Tomography (CT)-Guided Localization with Indocyanine Green for the Thoracoscopic Resection of Small Pulmonary Nodules

BACKGROUND

The identification of small lung nodules is challenging during mini-invasive thoracic surgery. Unable to palpate them directly, surgeons have developed several methods to preoperatively localize pulmonary nodules, including the computed tomography-guided positioning of coils or metallic landmarks (hook wire) or bronchoscopic marking.

METHODS

We present a series of patients scheduled for the video-assisted thoracoscopic sublobar resection of small pulmonary nodules, in which we performed preoperative percutaneous computed tomography (CT)-guided nodule localization through the injection of a mixture of indocyanine green and human albumin.

RESULTS

A total of 40 patients underwent a preoperative CT-guided injection of indocyanine green followed by VATS resection within 24 h. Patients tolerated the procedure well, no pain medication was administrated, and no complications were observed during the marking procedure. All pulmonary nodules were easily detected and successfully resected.

CONCLUSION

the near-infrared dye marking solution of indocyanine green (ICG) with diluted human albumin was safe, effective, and easy to perform. The ICG solution has the potential to facilitate the accurate localization and resection of pulmonary nodules during VATS surgery, avoiding the risk of marker displacement/migration.

A novel near-infrared EGFR targeting probe for metastatic lymph node imaging in preclinical mouse models

For the treatment of patients with oral squamous cell carcinoma (OSCC), the imaging of cervical lymph nodes and the evaluation of metastastic progression are of great significance. In recent years, the development of new non-radioactive lymph node tracers has been an area of intense research. Here, we report the synthesis, good biocompatibility, and in vivo evaluation of a new small molecule near-infrared (NIR) fluorescence probe by the conjugation of Lapatinib to S0456 (LP-S). We show that like Lapatinib, LP-S binds to the epidermal growth factor receptor (EGFR) resulting in high quality fluorescence imaging of metastatic lymph nodes in OSCC mouse models. After local injection of LP-S into the tumor, the lymphatic drainage pathway and lymph nodes can be clearly identified by NIR fluorescence imaging. Further, the LP-S probe shows higher contrast and longer retention in metastatic lymph nodes, allowing them to be differentiated from normal lymph nodes, and affording a new choice for fluorescence-guided surgery. Scheme. Chemical synthesis and application of EGFR targeting probe LP-S for imaging of metastatic lymph nodes (mLNs) in OSCC.

Revisiting molecularly conformation-planarized organic dyes for NIR-II fluorescence imaging

Fluorescence imaging in the second window (NIR-II, 1000-1700 nm) provides deeper penetration depth and higher resolution, but there is still a dilemma for designing NIR-II dyes for simultaneously enhancing fluorescence efficiency and prolonging excitation wavelength. Herein, a molecular conformation planarization strategy has been revisited to guide the synthesis of two donor-acceptor-donor dyes (named T-BBT and BT-BBT). On the one hand, conformational planarization can extend the absorption peaks of T-BBT and BT-BBT to the NIR region with high molar extinction coefficients of 30.5 × 103 and 16.4 × 103 L (mol-1 cm-1) at 1064 nm, respectively. On the other hand, structural rigidity can weaken electronic vibration coupling-related non-radiative decay pathways, whereby both T-BBT and BT-BBT display rather high fluorescence efficiencies of 3.6% and 13.5% in solution. Furthermore, a molecular doping strategy is adopted to alleviate fluorescence quenching in the aggregated state by suppressing long-distance energy migration, and 2.5 wt% doped BT-BBT nanoparticles show a high fluorescence efficiency of 2.0%, which enables the application of in vivo deep NIR-II fluorescence imaging for vessels and tumors with high resolution under 980 nm excitation. This work demonstrates that organic dyes with structural planarization can bridge the gap between NIR-II absorption and fluorescence efficiency.

Effect of indocyanine green near-infrared light imaging technique guided lymph node dissection on short-term clinical efficacy of minimally invasive radical gastric cancer surgery: a meta-analysis

Objective

In recent years, the utilization of indocyanine green near-infrared (ICG NIR) light imaging-guided lymph node dissection in the context of minimally invasive radical gastric cancer has emerged as a novel avenue for investigation. The objective of this study was to assess the influence of employing this technique for guiding lymph node dissection on the short-term clinical outcomes of minimally invasive radical gastric cancer surgery.

Methods

The present study conducted a comprehensive search for short-term clinical outcomes, comparing the group undergoing ICG NIR light imaging-guided lymph node dissection with the control group, by thoroughly examining relevant literature from the inception to July 2023 in renowned databases such as PubMed, Embase, Web of Science, and Cochrane Library. The primary endpoints encompassed postoperative complications, including abdominal infection, abdominal bleeding, pneumonia, anastomotic fistula, and overall incidence of complications (defined as any morbidity categorized as Clavien-Dindo class I or higher within 30 days post-surgery or during hospitalization). Additionally, secondary outcome measures consisted of the time interval until the initiation of postoperative gas and food intake, as well as various other parameters, namely postoperative hospital stay, operative time, intraoperative blood loss, total number of harvested lymph nodes, and the number of harvested metastatic lymph nodes. To ensure methodological rigor, the Cochrane Collaboration Risk of Bias Tool and the Newcastle-Ottawa Scale (NOS) were employed to assess the quality of the included studies, while statistical analyses were performed using Review Manager 5.4 software and Stata, version 12.0 software.

Results

A total of 19 studies including 3103 patients were ultimately included (n=1276 in the ICG group and n=1827 in the non-ICG group). In this meta-analysis, the application of ICG near-infrared light imaging in minimally invasive radical gastric cancer surgery effectively improved the occurrence of postoperative Clavien-Dindo grade II or higher complications in patients (RR=0.72, 95% CI 0.52 to 1.00) with a statistically significant P=0.05; in reducing intraoperative blood loss and shortening While reducing intraoperative blood loss and shortening postoperative hospital stay, it could ensure the thoroughness of lymph node dissection in minimally invasive radical gastric cancer surgery (MD=5.575, 95% CI 3.677-7.473) with significant effect size (Z=5.76, p<0.00001).

Conclusion

The utilization of indocyanine green near-infrared light imaging technology in the context of minimally invasive radical gastric cancer surgery demonstrates notable efficacy in mitigating the occurrence of postoperative complications surpassing Clavien-Dindo grade II, while concurrently augmenting both the overall quantity of lymph node dissections and the identification of positive lymph nodes, all the while ensuring the preservation of surgical safety. Furthermore, the implementation of this technique proves particularly advantageous in the realm of robotic-assisted radical gastric cancer surgery, thus bearing significance for enhancing the short-term prognostic outcomes of patients.

Efficacy of indocyanine green fluorescence for the identification of non-palpable breast tumours: systematic review

BACKGROUND

Accurate tumour localization is crucial for precise surgical targeting and complete tumour removal. Indocyanine green fluorescence, an increasingly used technique in oncological surgery, has shown promise in localizing non-palpable breast tumours. The aim of this systematic review was to describe the efficacy of indocyanine green fluorescence for the identification of non-palpable breast tumours.

METHODS

A systematic literature search was performed in PubMed, Embase, and the Cochrane Library, including studies from 2012 to 2023. Studies reporting the proportion of breast tumours identified using indocyanine green fluorescence were included. The quality of the studies and their risk of bias were appraised using the Methodological Index for Non-Randomized Studies ('MINORS') tool. The following outcomes were collected: identification rate, clear resection margins, specimen volume, operative time, re-operation rate, adverse events, and complications.

RESULTS

In total, 2061 articles were screened for eligibility, resulting in 11 studies, with 366 patients included: two RCTs, three non-randomized comparative studies, four single-arm studies, and two case reports. All studies achieved a 100 per cent tumour identification rate with indocyanine green fluorescence, except for one study, with an identification rate of 87 per cent (13/15). Clear resection margins were found in 88-100 per cent of all patients. Reoperation rates ranged from 0.0 to 5.4 per cent and no complications or adverse events related to indocyanine green occurred.

CONCLUSION

Indocyanine green fluorescence has substantial theoretical advantages compared with current routine localization methods. Although a limited number of studies were available, the current literature suggests that indocyanine green fluorescence is a useful, accurate, and safe technique for the intraoperative localization of non-palpable breast tumours, with equivalent efficacy compared with other localization techniques, potentially reducing tumour-positive margins.

Innovation versus Experimentation: An Application of Ethical Frameworks to the Acceptance of Fluorescence-Guided Pediatric Surgery

Innovation is essential to the advancement of the field of pediatric surgery. The natural skepticism toward new technologies in pediatrics leads to frequent confusion of surgical innovation and research. Using fluorescence-guided surgery as an archetype for this ethical discussion, we apply existing conceptual frameworks of surgical innovation to understand the distinction between innovation and experimentation, acknowledging the spectrum and "grey zone" in between. In this review, we discuss the role of Institutional Review Boards in evaluating surgical practice innovations, and the aspects of certain surgical innovations that are distinct from experimentation, including a thorough understanding of the risk profile, preexisting use in humans, and adaptation from related fields. Examining fluorescence-guided surgery through these existing frameworks as well as the concept of equipoise, we conclude that new applications of indocyanine green do not constitute human subjects research. Most importantly, this example gives practitioners a lens through which they may appraise potential surgical innovations to allow for a sensible and efficient improvement of the field of pediatric surgery. LEVEL OF EVIDENCE: V.

Synthesis, Optical Properties, and In Vivo Biodistribution Performance of Polymethine Cyanine Fluorophores

Near-infrared (NIR) cyanine dyes showed enhanced properties for biomedical imaging. A systematic modification within the cyanine skeleton has been made through a facile design and synthetic route for optimal bioimaging. Herein, we report the synthesis of 11 NIR cyanine fluorophores and an investigation of their physicochemical properties, optical characteristics, photostability, and in vivo performance. All synthesized fluorophores absorb and emit within 610-817 nm in various solvents. These dyes also showed high molar extinction coefficients ranging from 27,000 to 270,000 cm-1 M-1, quantum yields 0.01 to 0.33, and molecular brightness 208-79,664 cm-1 M-1 in the tested solvents. Photostability data demonstrate that all tested fluorophores 28, 18, 20, 19, 25, and 24 are more photostable than the FDA-approved indocyanine green. In the biodistribution study, most compounds showed tissue-specific targeting to selectively accumulate in the adrenal glands, lymph nodes, or gallbladder while excreted to the hepatobiliary clearance route. Among the tested, compound 23 showed the best targetability to the bone marrow and lymph nodes. Since the safety of cyanine fluorophores is well established, rationally designed cyanine fluorophores established in the current study will expand an inventory of contrast agents for NIR imaging of not only normal tissues but also cancerous regions originating from these organs/tissues.

The Use of Indocyanine Green and Near-Infrared Fluorescence Imaging Versus Blue Dye in Sentinel Lymph Node Biopsy in Cutaneous Melanoma: A Retrospective, Cohort Study

BACKGROUND

The use of indocyanine green (ICG) and near-infrared fluorescence imaging is a promising option for sentinel lymph node (SLN) mapping in cutaneous melanoma. The study objective was to compare the performance of ICG and blue dye at detecting SLNs with radioisotope nanocolloid (technetium-99).

METHODS

Between April 2018 and June 2022, 293 consecutive patients with cutaneous melanoma (Breslow thickness ≥ 0.8 mm) underwent wide local excision and SLN biopsy. Patients were divided into group A (ICG; n = 122) and group B (blue dye; n = 163). All patients underwent SPECT/CT imaging preoperatively. SLN detection parameters and complications were compared between the groups.

RESULTS

A total of 285 patients had complete data and were included in the analysis. The median age was 62.0 (range 10-91) years, and 139 (48.8%) were female patients. The mean Breslow thickness was 2.6 mm, 89 (31.2%) patients had ulceration, and 179 (62.8%) patients had mitosis ≥ 1 mm2. The mean number of SLNs detected per patient in group A was 1.58 and group B was 1.48. In groups A and B, the SLN detection rate was 96.7% versus 89.6% (p = 0.022) and the pathological SLN detection rate was 92.3% versus 97.1% (p = 0.481), respectively.

CONCLUSIONS

ICG had a higher SLN detection rate and equal pathological SLN detection rate to blue dye. ICG may not be inferior to blue dye and is a useful adjunct to radioisotope in SLN biopsy in cutaneous melanoma.

What is the best reconstruction procedure after esophagectomy? A meta-analysis comparing posterior mediastinal and retrosternal approaches

Thoracic esophagectomy is a particularly invasive and complicated surgical procedure, with a reconstruction of the gastrointestinal tract, such as the stomach, jejunum, or colon. The posterior mediastinal, retrosternal, and subcutaneous routes are the three possible esophageal reconstruction routes. Each route has advantages and disadvantages, and the optimal reconstruction route after esophagectomy remains controversial. Additionally, the best anastomotic techniques after esophagectomy in terms of location (Ivor Lewis or McKeown) and suturing (manual or mechanical) are debatable. Our meta-analysis investigating postoperative complications after esophagectomy between the posterior mediastinal and retrosternal routes revealed that the posterior mediastinal route was associated with a significantly lower anastomotic leakage rate than the retrosternal route (odds ratio = 0.78, 95% confidence interval: 0.70-0.87, p < 0.0001). Conversely, pulmonary complications (odds ratio = 0.80, 95% confidence interval: 0.58-1.11, p = 0.19) and mortality between the posterior mediastinal and retrosternal routes (odds ratio = 0.79, 95% confidence interval: 0.56-1.12, p = 0.19) were not significantly different. However, the incidence of pneumonia may be lower when using the retrosternal route rather than the posterior mediastinal route for performing minimally invasive esophagectomy. The McKeown procedure is oncologically necessary for tumors located above the carina to dissect upper mediastinal and cervical lymph nodes; however, the Ivor Lewis procedure offers perioperative and oncological safety for tumors located under the carina. An individualized treatment strategy for selecting the optimal reconstruction procedure can be proposed in future studies based on oncological and patient risk factors considering mid- to long-term quality of life.

Exploring the Applications of Indocyanine Green in Robot-Assisted Urological Surgery: A Comprehensive Review of Fluorescence-Guided Techniques

This comprehensive review aims to explore the applications of indocyanine green (ICG) in robot-assisted urological surgery through a detailed examination of fluorescence-guided techniques. An extensive literature search was conducted in PubMed/MEDLINE, EMBASE and Scopus, using keywords such as "indocyanine green," "ICG", "NIRF", "Near Infrared Fluorescence", "robot-assisted", and "urology". Additional suitable articles were collected by manually cross-referencing the bibliography of previously selected papers. The integration of the Firefly^® technology in the Da Vinci^® robotic system has opened new avenues for the advancement and exploration of different urological procedures. ICG is a fluorophore widely used in near-infrared fluorescence-guided techniques. The synergistic combination of intraoperative support, safety profiles and widespread availability comprises an additional asset that empowers ICG-guided robotic surgery. This overview of the current state of the art illustrates the potential advantages and broad applications of combining ICG-fluorescence guidance with robotic-assisted urological surgery.

Application of indocyanine green in surgery: A review of current evidence and implementation in trauma patients

Background: Modern surgical medicine strives to manage trauma while improving outcomes using functional imaging. Identification of viable tissues is crucial for the surgical management of polytrauma and burn patients presenting with soft tissue and hollow viscus injuries. Bowel anastomosis after trauma-related resection is associated with a high rate of leakage. The ability of the surgeon’s bare eye to determine bowel viability remains limited, and the need for a more standardized objective assessment has not yet been fulfilled. Hence, there is a need for more precise diagnostic tools to enhance surgical evaluation and visualization to aid early diagnosis and timely management to minimize trauma-associated complications. Indocyanine green (ICG) coupled with fluorescence angiography is a potential solution for this problem. ICG is a fluorescent dye that responds to near-infrared irradiation. Methods: We conducted a narrative review to address the utility of ICG in the surgical management of patients with trauma as well as elective surgery. Discussion: ICG has many applications in different medical fields and has recently become an important clinical indicator for surgical guidance. However, there is a paucity of information regarding the use of this technology to treat traumas. Recently, angiography with ICG has been introduced in clinical practice to visualize and quantify organ perfusion under several conditions, leading to fewer cases of anastomotic insufficiency. This has great potential to bridge this gap and enhance the clinical outcomes of surgery and patient safety. However, there is no consensus on the ideal dose, time, and manner of administration nor the indications that ICG provides a genuine advantage through greater safety in trauma surgical settings. Conclusions: There is a scarcity of publications describing the use of ICG in trauma patients as a potentially useful strategy to facilitate intraoperative decisions and to limit the extent of surgical resection. This review will improve our understanding of the utility of intraoperative ICG fluorescence in guiding and assisting trauma surgeons to deal with the intraoperative challenges and thus improve the patients’ operative care and safety in the field of trauma surgery.

Buccal mucosal application of dissolvable microneedle patch containing photosensitizer provides effective localized delivery and phototherapy against oral carcinoma

The effectiveness of phototherapy using photosensitizers is limited by the challenges in their delivery at the site of irradiation. Here, we demonstrate the localized application of a photosensitizer-loaded microneedle patch for effective photodynamic and photothermal therapy in oral carcinoma. Indocyanine green (ICG) was studied as a photosensitizer for its effect on oral carcinoma, FaDu cells. Different parameters including concentration, near-infrared (NIR) laser irradiation intensity and irradiation time were optimized while measuring temperature increase and reactive oxygen species (ROS) generation in FaDu cells. A dissolvable microneedle (DMN) patch made of sodium carboxymethyl cellulose and sodium alginate was fabricated by the micromolding technique. DMN showed sufficient mechanical strength for insertion in the excised porcine buccal mucosa. DMN dissolved within 30 s in phosphate buffer and 30 min in the excised buccal mucosa. Confocal microscopy studies revealed DMN penetration up to a depth of 300 µm within the buccal mucosa. ICG-DMN applied on the back of the rat was found to be localized at the application site before and after irradiation using an 808 nm NIR laser. ICG-DMN was applied on the FaDu xenografted tumor model in athymic nude mice. The localized temperature increase and ROS generation significantly (P<0.05) decreased the tumor volume after ICG-DMN application compared with the control group. In conclusion, DMN can be developed for the localized administration of photosensitizers for phototherapy in oral carcinoma.

Mapping the Lymphatic Drainage Pattern of Esophageal Cancer with Near-Infrared Fluorescent Imaging during Robotic Assisted Minimally Invasive Ivor Lewis Esophagectomy (RAMIE)-First Results of the Prospective ESOMAP Feasibility Trial

While the sentinel lymph node concept is routinely applied in other surgical fields, no established and valid modality for lymph node mapping for esophageal cancer surgery currently exists. Near-infrared light fluorescence (NIR) using indocyanine green (ICG) has been recently proven to be a safe technology for peritumoral injection and consecutive lymph node mapping in small surgical cohorts, mostly without the usage of robotic technology. The aim of this study was to identify the lymphatic drainage pattern of esophageal cancer during highly standardized RAMIE and to correlate the intraoperative images with the histopathological dissemination of lymphatic metastases. Patients with clinically advanced stage squamous cell carcinoma or adenocarcinoma of the esophagus undergoing a RAMIE at our Center of Excellence for Surgery of the Upper Gastrointestinal Tract were prospectively included in this study. Patients were admitted on the day prior to surgery, and an additional EGD with endoscopic injection of the ICG solution around the tumor was performed. Intraoperative imaging procedures were performed using the Stryker 1688 or the FIREFLY fluorescence imaging system, and resected lymph nodes were sent to pathology. A total of 20 patients were included in the study, and feasibility and safety for the application of NIR using ICG during RAMIE were shown. NIR imaging to detect lymph node metastases can be safely performed during RAMIE. Further analyses in our center will focus on pathological analyses of ICG-positive tissue and quantification using artificial intelligence tools with a correlation of long-term follow-up data.

Intraoperative angiography of the neurovascular bundle using indocyanine green and near-infrared fluorescence improves anatomical dissection during robot-assisted radical prostatectomy: initial clinical experience

Landmark artery identification in the neurovascular bundle (NVB) is important for nerve-sparing in radical prostatectomy. We aimed to investigate intraoperative angiography using indocyanine green and near-infrared fluorescence (ICG-NIRF) during robot-assisted radical prostatectomy (RARP) to identify the NVB, visualise vascularisation and haemostasis, and preserve erectile function. Our retrospective, unicentric study was performed in consecutive localised prostate cancer RARP patients (stage T1/T2, prostate-specific antigen < 10 ng/ml) who underwent ICG-NIRF angiography in France (2016-2021). When ready to dissect the NVB, the anaesthesiologist intravenously injected ICG (3 ml); the surgeon used alternating standard light or fluorescence to optimise NVB visualisation and facilitate microdissection. Primary outcomes: safety and feasibility of ICG-NIRF. Secondary outcomes: functional erectile dysfunction (Sexual Health Inventory for Men (SHIM) questionnaire) over 9 months, proportion of bilateral NVBs identified, ICG-related complications. Standard descriptive statistics were used; t test determined the significance of changes in SHIM scores versus baseline. Ninety-one patients received intraoperative angiography. The NVB was identified in all cases, without difficulties. No ICG-related complications or allergies were observed. There was no significant difference in the SHIM score at 9 months compared with baseline (p = 0.331), and erectile dysfunction returned to baseline levels in almost all patients. Intraoperative, real-time ICG-NIRF angiography is simple, non-invasive, and improves identification of key anatomical landmarks to optimise micropreservation of the NVB during RARP and preserve erectile function. Larger clinical studies should confirm preliminary results.

Is ICG essential in all colorectal surgery? A 3-year experience in a single center: a cohort study

INTRODUCTION AND OBJECTIVES

Indocyanine green (ICG) was introduced as a promising diagnostic tool to provide real-time assessment of intestinal vascularization. Nevertheless, it remains unclear whether ICG could reduce the rate of postoperative AL. The objective of this study is to assess its usefulness and to determine in which patients is most useful and would benefit the most from the use of ICG for intraoperative assessment of colon perfusion.

METHODS

A retrospective cohort study was conducted in a single center, including all patients who underwent colorectal surgery with intestinal anastomosis between January 2017 and December 2020. The results of patients in whom ICG was used prior to bowel transection were compared with the results of the patients in whom this technique was not used. Propensity score matching (PSM) was employed to compare groups with and without ICG.

RESULTS

A total of 785 patients who underwent colorectal surgery were included. The operations performed were right colectomies (35.0%), left colectomies (48.3%), and rectal resections (16.7%). ICG was used in 280 patients. The mean time since the infusion of ICG until detection of fluorescence in the colon wall was 26.9 ± 1.2 s. The section line was modified in 4 cases (1.4%) after ICG due to a lack of perfusion in the chosen section line. Globally, a non-statistically significant increase in anastomotic leak rate was observed in the group without ICG (9.3% vs. 7.5%; p = 0.38). The result of the PSM was a coefficient of 0.026 (CI - 0.014 to 0.065, p = 0.207).

CONCLUSIONS

ICG is a safe and useful tool to assess the perfusion of the colon prior to performing the anastomosis in colorectal surgery. However, in our experience, it did not significantly lower the anastomotic leakage rate.

The Evolution of Fluorescence-Guided Surgery

There has been continual development of fluorescent agents, imaging systems, and their applications over the past several decades. With the recent FDA approvals of 5-aminolevulinic acid, hexaminolevulinate, and pafolacianine, much of the potential that fluorescence offers for image-guided oncologic surgery is now being actualized. In this article, we review the evolution of fluorescence-guided surgery, highlight the milestones which have contributed to successful clinical translation, and examine the future of targeted fluorescence imaging.

Opportunities of ICG-fluorescent imaging of lymph nodes during radical cystectomy in patients with bladder cancer: A review

Today, the "golden standard" for the treatment of aggressive forms of bladder cancer is radical cystectomy. An important stage is the pelvic lymphadenectomy. This procedure is crucial for staging the tumor process, determining the subsequent treatment tactics and improving the results of surgery. Currently, the concept of a signaling lymph node (LN) is actively developing, which allows reducing the necessary level of dissection of the pelvic LN. Reducing the number of resected LN increases the level of surgical safety of the patient. The leading method of intraoperative visualization of signal LN is the fluorescence of indocyanine green in the near infrared range of the spectrum. The prospects of this diagnostic method for radical cystectomy in patients with bladder cancer determine the vector of future scientific research in this area.