Real-time fluorescence imaging in intraoperative decision making for cancer surgery

Enhancing clinical precision in lung cancer tissue biopsy through elevated response-threshold of an endoplasmic reticulum-targeted fluorogenic probe

Lung carcinoma is the leading cause of mortality globally, posing a significant public health concern. Fluorescent-mediated tumor imaging is emerging as a novel diagnostic and therapeutic approach in clinical practice. Nevertheless, traditional probes lack accuracy in diagnosing tumors due to the overlap in baseline values of certain tumor biomarkers between normal and tumor cells as both exhibit turn-on fluorescence, rendering it impossible to distinguish tumor tissue from normal tissue with high resolution. We introduce a sensing strategy that constructs a probe with an elevated biomarker response-threshold and targeting ability for the endoplasmic reticulum (ER), enabling precise distinction between tumor and normal cells, and successfully develop such a probe. Elevating the response-threshold is advantageous in minimizing interference from baseline values of biomarkers in normal cells. Additionally, targeting the ER ensures that the probe's response range is consistent with the biomarker content in the ER, collectively enhancing differentiation between normal and cancer cells. Using this novel probe, a distinct bright fluorescence signal from tumors could be observed in confocal imaging of tumor tissues from tumor-bearing mice after intravenous injection, in stark contrast to the limited fluorescence emanating from normal tissues. Furthermore, this probe demonstrated exceptional precision in distinguishing clinical lung cancer tissue from para-cancer tissue. This work presents a more reliable tumor detection strategy, capable of accurate diagnosis even when the biomarker is highly expressed in both normal and tumor tissues. It promises to be a valuable tool for future clinical applications, particularly in intraoperative assisted resection.

Ir-organometallic compounds-mediated internal and external dual-phototheranostics for collaborative antitumor therapy

Cerenkov light-based excitation represents an attractive alternative to conventional external light excitation, aiming to break the penetration limitations of in vivo optical imaging and therapy. However, Cerenkov light's inherent deficiency severely restricts its potential applications in tumor theranostic. Herein, we have seamlessly integrated organometallic compounds with radio-phototheranostics for the first time, achieving significant tumor inhibition and the inaugural instance of a radionuclide(18F)-activated NIR photosensitizer with a wavelength exceeding 800 nm through the innovative "internal-external attack" design and "two-in-one" internal energy transfer. In this study, coumarin 6 and IR775 derivatives were connected via iridium atoms to construct dual-function iridium-organometallic compounds (IR-C6Ir), combining internal and external responsive molecules for dual phototherapy and Cerenkov light red-shift fluorescence imaging. IR-C6Ir can be preferably accumulated at mitochondrial at the tumor site, inducing excellent anti-tumor effect with a 92.5 % tumor volume reduction at the lower concentration (0.65 μM) and excitation level (800 μCi of 18F and 0.5 W/cm2 of 808 nm laser irradiation). In addition, IR-C6Ir-mediated internal and external phototherapy exhibited the synergistic enhancement effect of "1 + 1>2" and achieved tumor multiplex visualization. The combination of internal phototherapy and external phototherapy motifs in one molecule, provides IR-C6Ir with a novel strategy for high-efficiency and low-toxicity phototherapy.

Combined PET and near-infrared fluorescence probe based on lapatinib targeting HER2 for in vivo tumor imaging

Combination of PET and optical imaging techniques holds significant potential for complete tumor resection to optimize patient outcomes. In this study, we combined two lapatinib-based molecular probes for detecting HER2-overexoression tumors through PET and near-infrared (NIR) fluorescence imaging. HER2 receptor had been confirmed to be overexpressed in many types of tumors and had become a specific target for molecular imaging. The radiolabeled probe [68Ga] Ga-NOTA-lapatinib demonstrated superior imaging performance in micro-PET scans, achieving clear differentiation of subcutaneous tumors from adjacent tissues. Complementarily, the NIR fluorescent probe LP-S exhibited prolonged tumor retention (>72 h) with distinct signal demarcation between malignant and normal tissues in ex vivo analyses. Fluorescence microscopy further validated specific intra-tumoral accumulation of the probe at cellular resolution. This synchronized dual-probe strategy, leveraging identical targeting moieties, established a robust platform for multimodality cancer imaging that bridges preoperative detection with intraoperative visualization.

Comparative Analysis of Long-Term Outcomes Between Near-Infrared Fluorescence Imaging with Indocyanine Green-Guided Mediastinal Lymphadenectomy and Conventional Surgery for Esophageal Cancer

BACKGROUND

This study aimed to compare the long-term oncologic outcomes of NIRF-guided mediastinal lymphadenectomy during esophagectomy with those of conventional surgery.

METHODS

The study enrolled consecutive patients who underwent esophagectomy for esophageal cancer by a single surgical team between September 2017 and July 2021. Patients treated after September 2019 received NIRF-guided mediastinal lymphadenectomy (NIRF group) and were compared with the earlier cohort (historical control group). Propensity-matching analysis was used to compare 3-year overall survival (OS), disease-free survival (DFS), and recurrence patterns between the groups. Survival outcomes were analyzed using Kaplan-Meier curves and Cox regression analysis.

RESULTS

The final analysis included 118 matched patients (NIRF group, 59; historical control group, 59). The median follow-up period for all the patients was 38 months (range, 33-42 months). The NIRF group showed a significantly higher number of total lymph nodes (P = 0.010) and mediastinal lymph nodes (P = 0.045) dissected than the historical control group. The 1- and 3-year DFS rates were 68.1% and 45.2% for the NIRF group versus 74.3% and 55.2% for the historical control group. The OS rates for the NIRF group were 90.6% (1-year rate) and 72.0% (3-year rate) versus 98.3% (1-year rate) and 76.9% (3-year rate) for the historical control group. Both OS and DFS were comparable between the two groups (P = 0.271 and P = 0.356, log-rank test, respectively). Additionally, the two groups had similar recurrence patterns (P = 0.053).

CONCLUSION

The use of NIRF imaging during esophagectomy facilitates precise resection of mediastinal lymph nodes. However, its impact on patient survival remains limited.

Fibroblast activation protein peptide-targeted NIR-I/II fluorescence imaging for stable and functional detection of hepatocellular carcinoma

PURPOSE

Cancer-associated fibroblasts (CAFs) are the primary stromal component of the tumor microenvironment in hepatocellular carcinoma (HCC), affecting tumor progression and post-resection recurrence. Fibroblast activation protein (FAP) is a key biomarker of CAFs. However, there is limited evidence on using FAP as a target in near-infrared (NIR) fluorescence imaging for HCC. Thus, this study aims to develop a novel NIR fluorescent imaging strategy targeting FAP+ CAFs in HCC.

METHODS

The ICG-FAP-TATA probe was synthesized by conjugating a novel cyclization anti-FAP peptide with an indocyanine green derivative (ICG-NH2) as fluorophore, capable for NIR window I (NIR-I, 700-900 nm) and II (NIR-II, 1000-1700 nm) imaging. Its efficacy in lesion localization and other potential applications was evaluated.

RESULTS

In vivo imaging of subcutaneous HCC models revealed that ICG-FAP-TATA specifically targeted FAP+ CAFs in the stroma and detected differences in CAFs loading within lesions. The fluorescence intensity/tumor-to-background ratio (TBR) positively correlated with FAP expression (R2 > 0.8, p < 0.05). Ex vivo incubation of tumor tissues with ICG-FAP-TATA provided stable fluorescence imaging of tumors in subcutaneous and orthotopic HCC models, including different cell line co-culture systems (LM3-luc, MHCC97H-luc, HepG2-luc + LX2), and various liver backgrounds (healthy/fibrotic) (n = 5 per group). TBR of the tumor mice models was higher for NIR-II than NIR-I imaging (3.89 ± 1.27 vs. 2.64 ± 0.64, p < 0.05). Moreover, NIR-I/II imaging of fresh tissues from seven patients with HCC undergoing surgery incubated with ICG-FAP-TATA visually provided the spatial distribution heterogeneity of CAFs. The targeted fluorescence was relatively enriched more in the blood flow direction and at the tumor edge, both of which were associated with tumor metastasis (all p < 0.05).

CONCLUSION

This study presents a rapid and effective method for detecting HCC lesions, locating FAP+ CAFs, and visualizing high-risk areas for tumor metastasis at the macroscopic level. It offers a new promising approach with translational potential for imaging HCC.

Molecular-Targeted Fluorescence Lymph Node Imaging Could Play a Clinical Role in the Surgical Setting: A Systematic Review

The lymphatic system plays a crucial role in the spread of solid tumors and is often the first site of metastasis, as cancer cells typically invade nearby lymph nodes (LN) before potentially spreading to other LNs through the lymphatic system and distant organs through the bloodstream [...].

Robotic-assisted colorectal surgery in colorectal cancer management: a narrative review of clinical efficacy and multidisciplinary integration

Colorectal cancer (CRC) remains a formidable global health challenge, ranking among the most prevalent malignancies and a principal contributor to cancer-associated mortality. While traditional open surgery has historically been the cornerstone of CRC treatment, the advent of minimally invasive techniques, particularly robotic-assisted colorectal surgery (RACS), has garnered significant momentum owing to technological advancements in the field. Robotic platforms, exemplified by the da Vinci Surgical System, offer superior three-dimensional visualization, enhanced dexterity, and heightened precision, yielding improved perioperative outcomes, particularly in anatomically intricate regions such as the pelvis. This review provides a critical appraisal of the current landscape of RACS, emphasizing its superiority over conventional open and laparoscopic approaches. The increased control and precision afforded by robotic surgery have been shown to optimize outcomes in complex procedures such as total mesorectal excision, with evidence indicating reduced intraoperative blood loss, shortened hospital stays, and improved functional recovery. Nonetheless, challenges persist, including absence of haptic feedback, prohibitive costs, and steep learning curve associated with robotic systems. Despite these limitations, RACS has demonstrated considerable promise in sphincter-preserving and function-preserving procedures, ultimately enhancing postoperative quality of life. Beyond the surgical field, this review also investigates the integration of robotic surgery within multidisciplinary treatment strategies for CRC, particularly in the context of locally advanced rectal cancer. The combination of robotic techniques with total neoadjuvant therapy and immunotherapy-especially in tumors characterized by mismatch repair deficiency or high microsatellite instability has shown notable clinical efficacy. Furthermore, emerging personalized therapeutic approaches, including immunotherapies and targeted chemotherapeutic agents, emphasize the transformative potential of RACS in delivering superior oncologic outcomes. Looking towards the future, innovations in robotic platforms, including intraoperative imaging, artificial intelligence, and augmented reality, herald new possibilities for further enhancing the precision and efficacy of colorectal surgeries. The standardization of RACS protocols, alongside ongoing training and robust clinical research, will be critical to fully realizing the benefits of these advancements across diverse clinical settings. By incorporating cutting-edge technologies and personalized treatment methods, robotic-assisted surgery is prepared to become a cornerstone in future of CRC management, with the potential to significantly improve both survival outcomes and patient quality of life.

A Near-Infrared Fluorescent Macromolecular Dye for Precise Identification of Glioblastoma Boundaries

Glioblastoma (GBM) is a highly invasive tumor with poorly defined boundaries, often leaving residual tissue after surgery, which contributes to the recurrence and poor prognosis. A critical challenge in GBM treatment is the precise identification of tumor boundaries during surgery to achieve a safe and complete resection. In this study, we present a novel near-infrared fluorescent agent, IR-PEG-cRGD, that is designed to accurately delineate GBM boundaries for surgical navigation of tumor resection. IR-PEG-cRGD is successfully prepared from the cyanine dye IR-820, which is conjugated to poly(ethylene glycol) (PEG) to prolong circulation time and enhance tumor accumulation. Additionally, a glioma-targeting peptide (cRGD, cyclo(Arg-Gly-Asp-d-Phe-Cys)) is conjugated to PEG to selectively target GBM. IR-PEG-cRGD demonstrates effective targeting and enrichment in subcutaneous human-derived GBM mice models, enabling specific distinguishing of the GBM margin from the surrounding parenchyma with a high signal-to-background ratio (SBR) of 4.79. Moreover, IR-PEG-cRGD can pass across the blood-brain barrier (BBB) efficiently. These findings indicate that IR-PEG-cRGD can serve as a valuable tool for the precise intraoperative delineation of GBM boundaries, aiding in safe and complete tumor resection.

Novel functionalized benzimidazole-salicylic acid derivatives: synthesis, photophysical characteristics and biological applications

Although the benzimidazole moiety is a versatile heterocyclic unit that has been widely applied in optical materials and medicinal chemistry, there are few bifunctional small-molecule benzimidazole derivatives with bio-activity and fluorescence. In this work, a series of novel benzimidazole-salicylic acid molecules were designed and synthesized; their optical properties were evaluated and their potential biological application was explored. The representative compound 5q exhibited excellent fluorescence properties, displaying blue imaging in HeLa cells and zebrafish. Additionally, it exhibited high selectivity for Fe3+ ions and demonstrated a notable inhibitory activity with IC50 = 6.86 ± 2.82 μM against SHP1PTP. Further effort was applied to explore the potential capability of compound 5q to reactivate the activity of SHP1 when inhibited by Fe3+ ions, indicating that compound 5q could be a fluorescent modulator to adjust SHP1 enzyme activity in biological systems.

Application of a CYP1B1-Targeted NIR Probe for Breast Cancer Diagnosis, Surgical Navigation, and CYP1B1-Associated Chemotherapy Resistance Monitoring

Early detection and precise treatment for breast cancer are crucial, given its high global incidence rate. Hence, the development of novel imaging targets is essential for diagnosing and monitoring resistance to chemotherapy, which is pivotal for achieving precise and personalized treatment for breast cancer patients. In our previous work, we successfully developed a near-infrared (NIR) probe 1 for CYP1B1-targeted imaging. In this study, we aimed to investigate the utility of the probe as a NIR fluorescence and photoacoustic dual-mode imaging probe for the detection and surveillance of breast cancer. Western blotting of cancer cell lines has confirmed that CYP1B1 is widely expressed in breast cancer and gynecological cancer. In vitro NIR fluorescence imaging capability of the probe for tracking CYP1B1-positive tumor cells was validated by using confocal microscopy. Further studies, including in vivo fluorescence and photoacoustic dual-model imaging and ex vivo biological distribution analysis on a triple-negative breast cancer xenograft mouse model, demonstrated that the probe selectively accumulated in tumor tissue within as early as 0.5 h postinjection. The results of the surgical resection experiment revealed that the tumor could be entirely removed under the guidance of NIR imaging, thereby indicating the probe's efficacy in surgical navigation. CYP1B1 expression was found to be upregulated in adriamycin (ADR)-resistant breast cancer cells, MCF-7/ADR. Consequently, the sensitivity of CYP1B1 overexpressed cells, MCF-7/1B1, to ADR was significantly reduced, with an IC50 value of 0.586 ± 0.0934 μM, compared to the parental MCF-7 cells with an IC50 value of 0.183 ± 0.0444 μM. In vivo and ex vivo imaging assays conducted on MCF-7/ADR tumor-bearing mice demonstrated that the probe was specifically enriched in tumor sites, suggesting its potential for monitoring chemotherapy resistance in breast cancer. This study expands the scope of application for NIR probe 1, establishing its utility in breast cancer diagnosis through fluorescence-photoacoustic dual-model imaging, monitoring of chemotherapy resistance, and guidance for surgical resection. This strategy paves the way for novel approaches to precise and personalized treatment for breast cancer patients.

Deep Equilibrium Unfolding Learning for Noise Estimation and Removal in Optical Molecular Imaging

In clinical optical molecular imaging, the need for real-time high frame rates and low excitation doses to ensure patient safety inherently increases susceptibility to detection noise. Faced with the challenge of image degradation caused by severe noise, image denoising is essential for mitigating the trade-off between acquisition cost and image quality. However, prevailing deep learning methods exhibit uncontrollable and suboptimal performance with limited interpretability, primarily due to neglecting underlying physical model and frequency information. In this work, we introduce an end-to-end model-driven Deep Equilibrium Unfolding Mamba (DEQ-UMamba) that integrates proximal gradient descent technique and learnt spatial-frequency characteristics to decouple complex noise structures into statistical distributions, enabling effective noise estimation and suppression in fluorescent images. Moreover, to address the computational limitations of unfolding networks, DEQ-UMamba trains an implicit mapping by directly differentiating the equilibrium point of the convergent solution, thereby ensuring stability and avoiding non-convergent behavior. With each network module aligned to a corresponding operation in the iterative optimization process, the proposed method achieves clear structural interpretability and strong performance. Comprehensive experiments conducted on both clinical and in vivo datasets demonstrate that DEQ-UMamba outperforms current state-of-the-art alternatives while utilizing fewer parameters, facilitating the advancement of cost-effective and high-quality clinical molecular imaging.

Metabolic Acidity/H2O2 Dual-Cascade-Activatable Molecular Imaging Platform Toward Metastatic Breast Tumor Malignancy

Fluorescence imaging in the second near-infrared window (NIR-II) is crucial for accurate tumor diagnosis, offering superior resolution and penetration capabilities. Current NIR-II probes are limited by either being "always on" or responding to one stimulus, leading to low signal-to-noise ratios and potential false positives. We introduced a dual-lock-controlled probe, HN-PBA, activated by both H2O2 and tumor acidic environment. This dual response ensures bright fluorescence at tumor sites, leading to higher tumor-to-normal tissue ratios (T/NT) compared to conventional "always on" probes and probes activated only by H2O2. This strategy allows precise tumor identification and removal of primary and metastatic tumors, achieving superior T/NT ratios (24.3/6.4 for orthotopic and lung metastasis, respectively). Our probe also effectively detected lung metastatic foci as small as≤0.7 mm and showed the capability for accurate lesion localization in clinical breast cancer specimens. This dual-stimuli-responsive strategy could aid future diagnostic probe design.

Tumor agnostic ultrasmall nanoprobes for fluorescence-guided surgical resection in peritoneal metastasis

PURPOSE

Surgical excision of metastases is the only curative treatment strategy in peritoneal carcinomatosis management, and the completeness of tumor resection determines the success of the surgery. Tumor-specific fluorescence-guided probes can improve the outcomes of cytoreductive surgery and thereby prognosis. This study aimed to develop and evaluate the feasibility of fluorescently labeled ultrasmall porous silica nanoparticles (UPSN) for image-guided resection of peritoneally disseminated tumors of different origins.

METHODS

Ultrasmall fluorescent nanoprobes were synthesized and characterized for their physicochemical properties and stability. Tumor-specific uptake and biodistribution profiles were evaluated in syngeneic CT26 colorectal and KPC-689 pancreatic cancer murine models. The practicability of real-time optical UPSN-guided resection was examined in the CT26 colorectal cancer model using a surgical stereomicroscope. Quantitative measurements of tumor sensitivity and specificity were performed. Histopathological examination validated in vivo findings about tumor-specific accumulation and safety of ultrasmall fluorescent probes.

RESULTS

As-synthesized UPSNs were successfully surface modified with Cy5 or Cy3 dyes maintaining sub-15 nm size and near neutral charge which is beneficial for optimized in vivo pharmacokinetics. UPSN-Cy5 demonstrated high tumor-specific uptake and favorable biodistribution profiles in peritoneal metastasis models of CT26 and KPC tumors. Dye-conjugated UPSN enabled resection of microscopic lesions and achieved a higher tumor-to-background ratios in comparison to FDA-approved indocyanine green (ICG) dye in both models. Microscopic evaluation showed tumor localization and off-target safety profile of the UPSN-Cy5.

CONCLUSION

Ultrasmall fluorescent probes were effective in surgical resection of peritoneal metastases with high sensitivity and specificity, thus emerging as promising tumor agnostic agents for image-guided cancer surgery.

An Augmented Reality Visor for Intraoperative Visualization, Guidance, and Temperature Monitoring Using Fluorescence

Fluorescence-guided surgeries, including tumor resection and tissue soldering, are advancing the frontiers of surgical precision by offering enhanced control that minimizes tissue damage, improving recovery and outcomes. However, integrating fluorescence visualization with real-time temperature monitoring remains a challenge, limiting broader clinical use. We address this issue with an augmented reality (AR) visor that combines nanomaterial excitation, fluorescence detection, and temperature monitoring. Using advanced fluorescent nanoparticles like indocyanine green-doped particles and carbon nanotubes, the visor provides a comprehensive view of both the surgical field and sub-surface conditions invisible to the naked eye. This integration improves the safety and efficacy of fluorescence-guided surgeries, including laser tissue soldering, by ensuring optimal temperatures and laser guidance in real time. The presented technology enhances existing surgical techniques and supports the development of new strategies and sensing technologies in areas where traditional methods fall short, marking significant progress in precision surgery and potentially improving patient care.

Recent advances of photodiagnosis and treatment for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) are the most common type of head and neck tumor that severely threatens human health due to its highly aggressive nature and susceptibility to distant metastasis. The diagnosis of HNSCC currently relies on biopsy and histopathological examination of suspicious lesions. However, the early mucosal changes are subtle and difficult to detect by conventional oral examination. As for treatment, surgery is still the primary treatment modality. Due to the complex anatomy and the lack of intraoperative modalities to accurately determine the incision margins, surgeons are in a dilemma between extensive tumor removal and improving the quality of patient survival. As more knowledge is gained about HNSCC, the increasing recognition of the value of optical imaging has been emphasized. Optical technology offers distinctive possibilities for early preoperative diagnosis, intraoperative real-time visualization of tumor margins, sentinel lymph node biopsies, phototherapy. Fluorescence imaging, narrow-band imaging, Raman spectroscopy, optical coherence tomography, hyperspectral imaging, and photoacoustic imaging have been reported for imaging HNSCC. This article provides a comprehensive overview of the fundamental principles and clinical applications of optical imaging in the diagnosis and treatment of HNSCC, focusing on identifying its strengths and limitations to facilitate advancements in this field.

Conversion therapy strategy: A novel GPC3-targeted multimodal organic phototheranostics platform for mid-late-stage hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is typically diagnosed at intermediate to advanced stage, making surgical treatment unfeasible. Conversion therapy aims to reduce tumor stage, improve hepatic resection feasibility, and lower recurrence rates. Since traditional therapies are often accompanied by uncertainty of efficacy, there is an urgent need to explore new treatment strategies. Near-infrared phototheranostics technology provides a new way for HCC diagnosis and treatment by its excellent optical properties. However, complex preparation and poor biocompatibility of phototheranostics probes limit clinical application. In this study, we developed a fluorescence/magnetic resonance dual-modality imaging (FLI/MRI) as well as photothermal/photodynamic therapy (PTT/PDT) GPC3-targeted multifunctional phototheranostics probe, IR820-GPC3-Gd NPs (IGD NPs), to improve the efficiency of conversion therapy for HCC. The IGD NPs were simply prepared with the IR820 as the core. Conjugating the HCC-specific targeting molecule GPC3 peptide and the MRI agent DOTA-Gd through click chemistry. IGD NPs target HCC cells through GPC3, releasing heat and reactive oxygen species (ROS) under noninvasive 808 nm laser irradiation to reduce tumor size and achieve downstaging. High-sensitivity FLI/MRI precisely delineates tumor boundaries, providing real-time surgical navigation and prognosis assessment. This novel probe offers a feasible and effective treatment option for advanced HCC.

Accuracy of the LaserSAFE technique for detecting positive surgical margins during robot-assisted radical prostatectomy: blind assessment and inter-rater agreement analysis

INTRODUCTION AND OBJECTIVES

Fluorescence confocal microscopy (FCM) is a new imaging modality capable of generating digital microscopic resolution scans of fresh surgical specimens, and holds potential as an alternative to frozen section (FS) analysis for intra-operative assessment of surgical margins. Previously, we described the LaserSAFE technique as an application of FCM for margin assessment in robot-assisted radical prostatectomy (RARP) using the Histolog® scanner. This study describes the accuracy and inter-rater agreement of FCM imaging compared to corresponding paraffin-embedded analysis (PA) among four blinded pathologists for the presence of positive surgical margins (PSM).

MATERIALS AND METHODS

RARP specimens from patients enrolled in the control arm of the NeuroSAFE PROOF study (NCT03317990) were analysed from April 2022 to February 2023. Prostate specimens were imaged using the Histolog® scanner before formalin fixation and PA. Four trained assessors, blinded to PA, reviewed and analysed FCM images of the posterolateral prostatic surface.

RESULTS

A total of 31 prostate specimens were included in the study. PA per lateral side of the prostate identified 11 instances of positive margins. Among the four histopathologists included in our study, FCM achieved a sensitivity of 73-91 and specificity of 94-100% for the presence of PSM. Fleiss' Kappa for inter-rater agreement on PSM was 0.78 (95% confidence interval = 0.64-0.92), indicating substantial agreement.

CONCLUSION

This blinded analysis of FCM versus PA among histopathologists with different experience levels demonstrated high accuracy and substantial inter-rater agreement for diagnosing PSM. This supports the role of the FCM as an alternative to FS.

High Spatiotemporal Near-Infrared II Fluorescence Lifetime Imaging for Quantitative Detection of Clinical Tumor Margins

Accurate detection of tumor margins is essential for successful cancer surgery. While indocyanine green (ICG)-based near-infrared (NIR) fluorescence (FL) surgical navigation enhances the visual identification of tumor margins, its accuracy remains subjective, underscoring the need for quantitative approaches. In this study, a high spatiotemporal fluorescence lifetime (FLT) imaging technology is developed in the second near-infrared window (NIR-II, 1000-1700 nm) for quantitative tumor margin detection, utilizing folate receptor-targeted ICG nanoprobes (FPH-ICG). FPH-ICG exhibits a significantly prolonged NIR-II FLT (750 ± 7 ps vs 260 ± 3 ps) and increased NIR-II FL brightness (FPH-ICG/ICG = 3.8). In vitro and in vivo studies confirm that FPH-ICG specifically targets folate receptor-α (FRα) on SK-OV-3 ovarian cancer cells, achieving high-contrast NIR-II FL imaging with a signal-to-background ratio of 10.8. Notably, NIR-II FLT imaging demonstrates superior accuracy (90%) and consistency in defining tumor margins compared to NIR-II FL imaging (58%) in both SK-OV-3 tumor-bearing mice and clinical tumor samples. These findings underscore the potential of NIR-II FLT imaging as a quantitative tool for guiding surgical tumor margin detection.

Carbonic Anhydrase IX Targeted Polyaspartamide fluorescent Probes for Tumor imaging

Background

Precise intraoperative tumor delineation is essential for successful surgical outcomes. However, conventional methods are often incompetent to provide intraoperative guidance due to lack specificity and sensitivity. Recently fluorescence-guided surgery for tumors to delineate between cancerous and healthy tissues has attracted widespread attention. The contrast-enhanced fluorescent imaging has been applied for non-invasive diagnosis of cancers using tumor-targeting fluorescent probes.

Methods

The carbonic anhydrase IX targeted polyaspartamide fluorescent compounds (SD-PHEA-NI) were synthesized by incorporating a tumor-targeting group of sulfadiazine (SD) and N-butyl-4-ethyldiamino-1,8-naphthalimide (NI) into water-soluble carriersof poly-α,β-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA). These derivatives were also characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, ultraviolet-visible spectroscopy, nuclear magnetic resonance spectroscopy and fluorescence assays. The cellular uptake, cytotoxicity, and fluorescence imaging ability were evaluated.

Results

Experiment results indicated that SD-PHEA-NI has low cytotoxic to Henrietta Lacks (HeLa) cells. Moreover, B16F10 melanoma cells can take up SD-PHEA-NI and show good green fluorescent images. However, SD-PHEA-NI displayed a low-intensity green fluorescence signal in healthy human embryonic kidney (293T) cells.

Conclusion

SD-PHEA-NI can be considered a potential fluorescent probe for the detection of tumors. This study has the potential to enhance tumor diagnosis and image-guided surgical interventions by providing real-time information and robust decision support, thereby reducing recurrence and complication rates and ultimately improving patient outcomes.

Highly Selective AIEgen-Based "Turn On" Fluorescent Imaging for Inflammation Detection

Hypochlorous acid (HClO) is released by immune cells in the immune system, and it helps the body fight off infections and inflammation by killing bacteria, viruses, and other pathogens. However, tissue damage or apoptosis may also be induced by excess HClO. On this basis, we designed the probe TPE-NS by choosing tetraphenylethylene (TPE) as the luminescent unit and dimethylthiocarbamoyl chloride as the recognition site. By Gaussian's transition state calculations, HClO will cut off the photoinduced electron transfer (PET) effect of TPE-NS by hydrolysis reaction, thus emitting strong fluorescence. TPE-NS has rapid recognition and excellent specificity for HClO, and the limit of detection is 7.27 μM. Finally, TPE-NS was successfully used for the visualization of endogenous and exogenous HClO in cell experiments.

Systematic comparison of fluorescence imaging in the near-infrared and shortwave-infrared spectral range using clinical tumor samples containing cetuximab-IRDye800CW

Significance

Shortwave-infrared (SWIR) imaging is reported to yield better contrast in fluorescence-guided surgery than near-infrared (NIR) imaging, due to a reduction in scattering. This benefit of SWIR was shown in animal studies, however not yet in clinical studies with patient samples.

Aim

We investigate the potential benefit of SWIR to NIR imaging in clinical samples containing cetuximab-IRDye800CW in fluorescence-guided surgery.

Approach

The potential of the epidermal growth factor-targeted NIR dye cetuximab-IRDye800CW in the shortwave range was examined by recording the absorption and emission spectrum. An ex vivo comparison of NIR and SWIR images using clinical tumor samples of patients with penile squamous cell carcinoma (PSCC) and head and neck squamous cell carcinoma (HNSCC) containing cetuximab-IRDye800CW was performed. The comparison was based on the tumor-to-background ratio and an adapted contrast-to-noise ratio (aCNR) using the standard of care pathology tissue assessment as the golden standard.

Results

Based on the emission spectrum, cetuximab-IRDye800CW can be detected in the SWIR range. In clinical PSCC samples, overall SWIR imaging was found to perform similarly to NIR imaging (NIR imaging is better than SWIR in the 2/7 criteria examined, and SWIR is better than NIR in the 3/7 criteria). However, when inspecting HNSCC data, NIR is better than SWIR in nearly all (5/7) examined criteria. This difference seems to originate from background autofluorescence overwhelming the off-peak SWIR fluorescence signal in HNSCC tissue.

Conclusion

SWIR imaging using the targeted tracer cetuximab-IRDye800CW currently does not provide additional benefit over NIR imaging in ex vivo clinical samples. Background fluorescence in the SWIR region, resulting in a higher background signal, limits SWIR imaging in HNSCC samples. However, SWIR shows potential in increasing the contrast of tumor borders in PSCC samples, as shown by a higher aCNR over a line.

Fluorescence detection of pituitary neuroendocrine tumour during endoscopic transsphenoidal surgery using bevacizumab-800CW: a non-randomised, non-blinded, single centre feasibility and dose finding trial [DEPARTURE trial]

PURPOSE

Achieving endocrine remission by gross total resection is challenging in pituitary neuroendocrine tumours (PitNETs) with cavernous sinus invasion. This study aims to assess the safety, feasibility, and optimal dose for intraoperative fluorescence imaging as an added instrument to discriminate PitNET from surrounding tissue using bevacizumab-800CW, targeting vascular endothelial growth factor A (VEGF-A).

METHODS

In part I, dose-escalation (0-4∙5-10-25 mg) was performed in 4 groups of 3 patients with PitNETs Knosp grade 3-4. In part II, after interim analysis, the 10 mg and 25 mg groups were expanded to a total of 6 patients. Quantitative fluoroscence molecular endoscopy consisted of wide field fluorescence molecular endoscopy and multi-diameter single fiber reflectance / single fiber fluorescence spectroscopy. Mean fluorescence intensity (MFI) of the fresh surgical specimen was calculated and VEGF-staining was performed.

RESULTS

Eighteen patients were included. All doses were well tolerated. Three serious adverse events were registered, but none were tracer-related. Part I showed an adequate in-vivo tumour-to-background ratio for both 10 mg (TBR 2∙00 [1∙86, 2∙19]) and 25 mg (TBR 2∙10, [1∙86, 2∙58]). Part II revealed a substantially higher MFI in the 25 mg group. With both 10 mg and 25 mg a statistically significant difference between tumour and surrounding tissue was detected (p < 0∙0001). All surgical specimens had VEGF-A expression.

CONCLUSION

This study demonstrates the safety and feasibility of quantitative fluorescence molecular endoscopy during PitNET surgery. Both 10 mg and 25 mg bevacizumab-800CW result in clear differentiation in-vivo, with improved contrast ex-vivo (MFI) in the 25 mg group.

TRIAL REGISTRATION

NCT04212793 / Study Details| Detection of PitNET Tissue During TSS Using Bevacizumab800CW| ClinicalTrials.gov.

A near-infrared fluorescent probe with assembly/aggregation-induced retention effect for specific diagnosis of metastasis and image-guided surgery in breast cancer

Image-guided surgery is crucial for achieving complete tumor resection, reducing postoperative recurrence and improving patient survival. However, current clinical near-infrared fluorescent probes, such as indocyanine green (ICG), face two main limitations: 1) lack of active tumor targeting, and 2) short retention time in tumors, which restricts real-time imaging during surgery. To address these issues, we developed a near-infrared fluorescent probe capable of in situ nanofiber formation within tumor lesions. This probe actively targets the integrin αvβ3 receptors overexpressed on breast cancer cells and exhibits assembly/aggregation-induced retention effects at the tumor site, significantly extending the imaging time window. Additionally, we found that the probe's fluorescence intensity can be enhanced under receptor induction. Due to its excellent tumor specificity and sensitivity, 1FCG-FFGRGD not only identifies primary breast cancer but also precisely locates smaller lymph node metastases and detects sub-millimeter peritoneal metastases. In summary, this near-infrared probe, leveraging assembly/aggregation-induced retention effects, holds substantial potential for various biomedical applications.

Advances and challenges in precision imaging

Technological innovations in genomics and related fields have facilitated large sequencing efforts, supported new biological discoveries in cancer, and spawned an era of liquid biopsy biomarkers. Despite these advances, precision oncology has practical constraints, partly related to cancer's biological diversity and spatial and temporal complexity. Advanced imaging technologies are being developed to address some of the current limitations in early detection, treatment selection and planning, drug delivery, and therapeutic response, as well as difficulties posed by drug resistance, drug toxicity, disease monitoring, and metastatic evolution. We discuss key areas of advanced imaging for improving cancer outcomes and survival. Finally, we discuss practical challenges to the broader adoption of precision imaging in the clinic and the need for a robust translational infrastructure.

Flower-Like Nanosensors for Photoacoustic-Enhanced Lysosomal Escape and Cytoplasmic Marker-Activated Fluorescence: Enabling High-Contrast Identification and Photothermal Ablation of Minimal Residual Disease in Breast Cancer

The clearance of minimal residual disease (MRD) after breast cancer surgery is crucial for inhibiting metastasis and recurrence. However, the most promising biomarker-activated fluorescence imaging strategies encounter accessibility issues of the delivered sensors to cytoplasmic targets. Herein, a flower-like composite nanosensor with photoacoustic (PA) effect-enhanced lysosomal escape and cytoplasmic marker-activated fluorescence is developed to address this challenge. Specifically, the incorporation of Co2+ into the synthesis of 2D Zn2+-derived metal-organic frameworks enabled rapid dopamine polymerization and deposition. Subsequently, the composite nanoflower (FHN), characterized by an average size of ≈80 nm and petal thickness of ≈6 nm, is formed through the sealing of micropores and simultaneous cross-linking of nanosheets. The pronounced reduction in thermal conductivity of FHN, and superposition of interpetal thermal fields under a pulsed laser (PL), lead to enhanced PA effect and membrane permeability. Thereby, nanosensors efficiently escape from lysosomes resulting in synergistic fluorescence activation by dual-factors (ATP, miRNA-21) and DNA probes installed on FHN. A subsequently high tumor-to-normal tissue signal ratio (TNR) of 17.4 lead to precise guidance of NIR irradiation for efficient MRD eradication and recurrence inhibition. This study provides a new approach for high-contrast identification and precise ablation of MRD based on the synergistic response of endogenous and exogenous factors.

Recent Advancements of Nanomedicine in Breast Cancer Surgery

Breast cancer surgery plays a pivotal role in the multidisciplinary approaches. Surgical techniques and objectives are gradually shifting from tumor complete resection towards prolonging survival, improving cosmetic outcomes, and restoring the social and psychological well-being of patients. However, surgical treatment still faces challenges such as inadequate sensitivity in sentinel lymph node localization, the need to improve intraoperative tumor boundary localization imaging, postoperative scar healing, and the risk of recurrence, necessitating other adjunct measures for improvement. To address these challenges, specificity-optimized nanomedicines have been introduced into the surgical therapeutic landscape of breast cancer. In particular, this review involves starting with an overview of breast structure and the composition of the tumor microenvironment and then introducing the guiding principle and foundation for the design of nanomedicine. Moreover, we will take the order process of breast cancer surgery diagnosis and treatment as the starting point, and adaptively propose the roles and advantages of nanomedicine in addressing the corresponding issues. Furthermore, we also involved the prospects of utilizing advanced technological approaches. Overall, this review seeks to uncover the sophisticated design and strategies of nanomedicine from a clinical standpoint, address the challenges faced in surgical treatment, and provide insights into this subject matter.

Potential Probes for Targeted Intraoperative Fluorescence Imaging in Gastric Cancer

Gastric cancer (GC) is a malignant tumor of the gastrointestinal tract associated with high mortality rates and accounting for approximately 1 million new cases diagnosed annually. Surgery, particularly radical gastrectomy, remains the primary treatment; however, there are currently no specific approaches to better distinguish malignant from healthy tissue or to differentiate between metastatic and non-metastatic lymph nodes. As a result, surgeons have to remove all lymph nodes indiscriminately, increasing intraoperative risks for patients and prolonging hospital stay. Near-infrared fluorescence imaging with indocyanine green (ICG) can provide real-time visualization of the surgical field using both conventional laparoscopy and robotic mini-invasive precision surgery platforms. However, its application shows some limits, as ICG is a non-targeted contrast agent. Several studies are now investigating the potential efficacy of fluorescent targeted agents that could selectively bind to the tumor tissue, offering a valuable tool for metastatic mapping during robotic gastrectomy. This review aims to summarize the key fluorescent agents that have been developed to recognize GC markers, as well as those targeting the tumor microenvironment (TME) and metabolic features. These agents hold great potential as valuable tools for enhancing precision surgery in robotic gastrectomy procedures improving the clinical recovery of GC patients.

Realizing real-time optical molecular imaging in peripheral nerve tissue via Rhodamine B

Background

Iatrogenic nerve injury is a consequential complication during surgery. Thus, real-time imaging of peripheral nerve (PN) possesses significant clinical implications. In recent years, the rapid advancements in optical molecular imaging (OMI) technology have provided essential technical foundations for the implementation of PN fluorescence imaging. This study aimed to realize real-time OMI of PNs via Rhodamine B.

Methods

Phosphate buffered saline (PBS), normal saline (NS), 5% glucose solution (GS), and fetal bovine serum (FBS) were selected for measuring the fluorescence spectra of Rhodamine B solutions prepared in each formulation. Rhodamine B solutions, with varying doses dissolved in 100 μL of each formulation, were prepared and applied to the exposed PNs of the mice for incubation later. To ascertain the optimal formulation and dose of Rhodamine B, an analysis was performed on the signal-to-background ratio (SBR) of the nerves. Based on the experimental results, we proceeded to incubate Rhodamine B solution on the PN tissue of mice and human subjects, as well as on neuronal cells, to verify the binding sites of Rhodamine B with nerve. Subsequently, histological studies were conducted to validate the binding site between Rhodamine B and the nerves. Finally, we injected the optimal combination of Rhodamine B solution into mice via the tail vein and collected the SBR of mouse nerve tissues at different time intervals to determine the optimal pre-injection time. Fluorescence images of various tissues were collected, and Hematoxylin and Eosin (H&E) staining results were observed to determine the metabolism of Rhodamine B in mice and its toxicity.

Results

The excitation peak of Rhodamine B in PBS, NS, 5% GS, and FBS formulations was 554 nm, and the emission peak was 576 nm. In PBS group, the maximum SBR was 15.37 ± 0.68 while the dose of Rhodamine B was 8 nmol. Through ex-vivo validation on fresh human nerve tissue and verification using mouse and human tissue sections, we observed fluorescent signals of Rhodamine Bin the regions of nerve tissue and the fluorescence signals were all concentrated on the neuronal cell membranes. After injection, the fluorescent signal in nerve tissue reached its peak at 24 hours (h), coinciding with the highest SBR (5.93 ± 0.92) in mouse nerve tissues at this time point. Additionally, the fluorescence signal could be maintained for at least 48 h. Within 24 h, lung dilation and fusion of alveoli occurred. Then these pathological manifestations gradually diminished, returning to normal at 2 weeks (w), with no significant acute or chronic adverse reactions observed in other tissues.

Conclusion

Rhodamine B enables fluorescence imaging of PNs and has the potential for clinical translation.

Near-infrared fluorescent molecular probes with cetuximab in the in vivo fluorescence imaging for epithelial ovarian cancer

BACKGROUND

Near-infrared fluorescence (NIRF) imaging is an excellent choice for image-guided surgery due to its simple operation and non-invasiveness. Developing tumor-specific fluorescent molecular probes is key to fluorescence imaging-guided surgery. EGFR (epidermal growth factor receptor) is closely related to the proliferation and growth of tumor cells and is highly expressed in epithelial ovarian cancer (EOC). The study aims to construct a NIR fluorescent molecular probe using cetuximab (an EGFR monoclonal antibody) and investigate its feasibility for targeting EOC in vivo through fluorescence imaging.

METHODS

We determined the expression of EGFR in EOC. NIR fluorescent molecular probe with cetuximab (cetuximab-Cy7) was chemically engineered and identified. The subcutaneous xenografted tumor model of EOC was induced using SKOV3-Luc cell line with positive expression of EGFR. Cetuximab-Cy7 was used for in vivo fluorescence imaging, and phosphate-buffered saline, free Cy7 dye and mouse isotype immunoglobulin G-Cy7 were used as controls. NIRF imaging system was performed to study the distribution and targeting of the probes. Tumors were imaged in situ and ex vivo, and fluorescent intensity was quantified. Resected specimens were analyzed to confirm diagnosis, and immunohistochemical (IHC) staining was used to identify EGFR expression.

RESULTS

EGFR expression was increased in EOC tissues than fallopian tube tissues. The high expression of EGFR was significantly correlated with well-differentiation, residual lesions ≤ 1 cm, no recurrence and increased survival. NIRF imaging showed that the cetuximab-Cy7 enabled detection of tumor lesions in EOC-bearing mice with the optimal dose of 30 µg. The suitable imaging time window may be 24-96 h post-injection. Ex vivo fluorescence imaging indicated that fluorescent signal was mainly detected in the tumor and the lung. IHC results confirmed that xenografts were EGFR positive.

CONCLUSION

Cetuximab-Cy7 can specifically target the tumors of EOC xenografted nude mice. This research lays the foundation for future studies on EOC surgery navigation.

Trends in cancer imaging

Molecular imaging of cancer is a collaborative endeavor, uniting scientists and physicians from diverse fields. Such collaboration is actively developing and translating cutting-edge molecular imaging approaches to enhance the diagnostic landscape of human malignancies. The advent of positron emission tomography (PET) and PET imaging tracers has realized non-invasive target annotation and tumor characterization at the molecular level. In surgical procedures, novel imaging techniques, such as fluorescence or Cherenkov luminescence, help identify tumors and enhance surgical precision. Simultaneously, progress in imaging equipment, innovative algorithms, and artificial intelligence has opened avenues for next-generation cancer screening and imaging, augmenting the efficiency and accuracy of cancer diagnosis. In this review, we provide a panorama of molecular cancer imaging and ongoing developments in the field.

Progress of fluorescence imaging in lymph node dissection surgery for prostate and bladder cancer

Fluorescence imaging is a relatively new imaging method used to visualize different tissue structures to help guide intraoperative operations, which has potential advantages with high sensitivity and contrast compared to conventional imaging. In this work, we review fluorescent contrast agents and devices used for lymphatic system imaging. Indocyanine green is the most widely utilized due to its high sensitivity, specificity, low background fluorescence, and safety profile. In prostate and bladder cancer lymph node dissection, the complex lymphatic drainage can result in missed metastatic nodes and extensive dissection increases the risk of complications like lymphocele, presenting a significant challenge for urologists. Fluorescence-guided sentinel lymph node dissection facilitates precise tumor staging. The combination of fluorescence and radiographic imaging improves the accuracy of lymph node staging. Multimodal imaging presents new potential for precisely identifying metastatic pelvic lymph nodes.

Visualization of nonsmall-cell lung cancer by near-infrared fluorescence imaging with tumor-targeting peptide ABT-510

Nonsmall-cell lung cancer (NSCLC) is the most frequent type of lung cancer, with early surgical treatment proving vital for prolonged patient survival. However, precise visualization of NSCLC remains a challenge due to limited molecular imaging probes, the unique anatomical structure of the lungs, and respiratory movement interference. In this study, we investigated the potential utility of CD36, which is highly expressed in NSCLC, as an imaging target. A selective and water-soluble fluorescent probe, MPA-ABT-510, was successfully constructed by coupling ABT-510 with MPA, a near-infrared (NIR) fluorescent dye. Molecular docking analysis shows that MPA-ABT-510 possesses strong binding affinity to the CD36 protein, with specific hydrogen bond interactions at defined amino acid residues. In vitro assays reveals that the fluorescein isothiocyanate-labeled peptide ABT-510 specifically binds to the CD36-high expressing NSCLC cell lines H1299 and A549. In vivo imaging verifies that the MPA-ABT-510 efficiently accumulates in the tumor site with a distinct fluorescent signal. Ex vivo imaging revealed that tumor-to-lung fluorescence ratios for subcutaneous and orthotopic H1299 mouse models were 7.19 ± 0.73 and 1.91 ± 0.42, respectively, while those for A549 mice were 5.53 ± 0.64 and 1.77 ± 0.41, respectively. Biodistribution analysis demonstrated efficient MPA-ABT-510 uptake in H1299 and A549 liver metastases models with tumor-to-liver fluorescence ratios of 2.47 ± 0.48 and 2.19 ± 0.22, respectively. High MPA-ABT-510 accumulation was evident in A549 intestinal metastases models, as evidenced by tumor-to-colorectal fluorescence ratios of 4.27 ± 0.11. MPA-ABT-510 exhibits superior imaging capabilities with minimal safety concerns, so it is a promising candidate for NSCLC surgical navigation.

Orbital Adipose Tissue: The Optimal Control for Back-Table Fluorescence Imaging of Orbital Tumors

Control tissue is essential for ensuring the precision of semiquantitative analysis in back-table fluorescence imaging. However, there remains a lack of agreement on the appropriate selection of control tissues. To evaluate the back-table fluorescence imaging performance of different normal tissues and identify the optimal normal tissue, a cohort of 39 patients with orbital tumors were enrolled in the study. Prior to surgery, these patients received indocyanine green (ICG) and following resection, 43 normal control tissues (34 adipose tissues, 3 skin tissues, 3 periosteal tissues, and 3 muscle tissues) were examined using back-table fluorescence imaging. The skin tissue demonstrated significantly elevated fluorescence intensity in comparison to the diseased tissue, whereas the muscle tissue exhibited a broad range and standard deviation of fluorescence signal intensity. Conversely, the adipose and periosteum displayed weak fluorescence signals with a relatively consistent distribution. Additionally, no significant correlations were found between the signal-to-background ratio (SBR) of adipose tissue and patients' ages, genders, weights, disease duration, tumor origins, dosing of administration of ICG infusion, and the time interval between ICG infusion and surgery. However, a positive correlation was observed between the SBR of adipose tissue and its size, with larger adipose tissues (>1 cm) showing an average SBR 27% higher than smaller adipose tissues (≤1 cm). In conclusion, the findings of this study demonstrated that adipose tissue consistently exhibited homogeneous hypofluorescence during back-table fluorescence imaging, regardless of patient clinical variables or imaging parameters. The size of the adipose tissue was identified as the primary factor influencing its fluorescence imaging characteristics, supporting its utility as an ideal control tissue for back-table fluorescence imaging.

Interim Phase II Results Using Panitumumab-IRDye800CW during Transoral Robotic Surgery in Patients with Oropharyngeal Cancer

PURPOSE

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has continually increased during the past several decades. Using transoral robotic surgery (TORS) significantly improves functional outcomes relative to open surgery for OPSCC. However, TORS limits tactile feedback, which is often the most important element of cancer surgery. Fluorescence-guided surgery (FGS) strategies to aid surgeon assessment of malignancy for resection are in various phases of clinical research but exhibit the greatest potential impact for improving patient care when the surgeon receives limited tactile feedback, such as during TORS. Here, we assessed the feasibility of intraoperative fluorescence imaging using panitumumab-IRDye800CW (PAN800) during TORS in patients with OPSCC.

PATIENTS AND METHODS

Twelve consecutive patients with OPSCC were enrolled as part of a nonrandomized, prospective, phase II FGS clinical trial using PAN800. TORS was performed with an integrated robot camera for surgeon assessment of fluorescence. Intraoperative and ex vivo fluorescence signals in tumors and normal tissue were quantified and correlated with histopathology.

RESULTS

Intraoperative robot fluorescence views delineated OPSCC from normal tissue throughout the TORS procedure (10.7 mean tumor-to-background ratio), including in tumors with low expression of the molecular target. Tumor-specific fluorescence was consistent with surgeon-defined tumor borders requiring resection. Intraoperative robot fluorescence imaging revealed an OPSCC fragment initially overlooked during TORS based on brightfield views, further substantiating the clinical benefit of this FGS approach.

CONCLUSIONS

The results from this patient with OPSCC cohort support further clinical assessment of FGS during TORS to aid resection of solid tumors.

Illuminating the future of precision cancer surgery with fluorescence imaging and artificial intelligence convergence

Real-time and accurate guidance for tumor resection has long been anticipated by surgeons. In the past decade, the flourishing material science has made impressive progress in near-infrared fluorophores that may fulfill this purpose. Fluorescence imaging-guided surgery shows great promise for clinical application and has undergone widespread evaluations, though it still requires continuous improvements to transition this technique from bench to bedside. Concurrently, the rapid progress of artificial intelligence (AI) has revolutionized medicine, aiding in the screening, diagnosis, and treatment of human doctors. Incorporating AI helps enhance fluorescence imaging and is poised to bring major innovations to surgical guidance, thereby realizing precision cancer surgery. This review provides an overview of the principles and clinical evaluations of fluorescence-guided surgery. Furthermore, recent endeavors to synergize AI with fluorescence imaging were presented, and the benefits of this interdisciplinary convergence were discussed. Finally, several implementation strategies to overcome technical hurdles were proposed to encourage and inspire future research to expedite the clinical application of these revolutionary technologies.

Dual-Locked Fluorescent Probes Activated by Aminopeptidase N and the Tumor Redox Environment for High-Precision Imaging of Tumor Boundaries

Clear delineation of tumor margins is essential for accurate resection and decreased recurrence rate in the clinic. Fluorescence imaging is emerging as a promising alternative to traditional visual inspection by surgeons for intraoperative imaging. However, traditional probes lack accuracy in tumor diagnosis, making it difficult to depict tumor boundaries accurately. Herein, we proposed an offensive and defensive integration (ODI) strategy based on the "attack systems (invasive peptidase) and defense systems (reductive microenvironment)" of multi-dimensional tumor characteristics to design activatable fluorescent probes for imaging tumor boundaries precisely. Screened out from a series of ODI strategy-based probes, ANQ performed better than traditional probes based on tumor unilateral correlation by distinguishing between tumor cells and normal cells and minimizing false-positive signals from living metabolic organs. To further improve the signal-to-background ratio in vivo, derivatized FANQ, was prepared and successfully applied to distinguish orthotopic hepatocellular carcinoma tissues from adjacent tissues in mice models and clinical samples. This work highlights an innovative strategy to develop activatable probes for rapid diagnosis of tumors and high-precision imaging of tumor boundaries, providing more efficient tools for future clinical applications in intraoperative assisted resection.

Near-infrared II fluorescence-guided glioblastoma surgery targeting monocarboxylate transporter 4 combined with photothermal therapy

BACKGROUND

Surgery is crucial for glioma treatment, but achieving complete tumour removal remains challenging. We evaluated the effectiveness of a probe targeting monocarboxylate transporter 4 (MCT4) in recognising gliomas, and of near-infrared window II (NIR-II) fluorescent molecular imaging and photothermal therapy as treatment strategies.

METHODS

We combined an MCT4-specific monoclonal antibody with indocyanine green to create the probe. An orthotopic mouse model and a transwell model were used to evaluate its ability to guide tumour resection using NIR-II fluorescence and to penetrate the blood-brain barrier (BBB), respectively. A subcutaneous tumour model was established to confirm photothermal therapy efficacy. Probe specificity was assessed in brain tissue from mice and humans. Finally, probe effectiveness in photothermal therapy was investigated.

FINDINGS

MCT4 was differentially expressed in tumour and normal brain tissue. The designed probe exhibited precise tumour targeting. Tumour imaging was precise, with a signal-to-background (SBR) ratio of 2.8. Residual tumour cells were absent from brain tissue postoperatively (SBR: 6.3). The probe exhibited robust penetration of the BBB. Moreover, the probe increased the tumour temperature to 50 °C within 5 min of laser excitation. Photothermal therapy significantly reduced tumour volume and extended survival time in mice without damage to vital organs.

INTERPRETATION

These findings highlight the potential efficacy of our probe for fluorescence-guided surgery and therapeutic interventions.

FUNDING

Jilin Province Department of Science and Technology (20200403079SF), Department of Finance (2021SCZ06) and Development and Reform Commission (20200601002JC); National Natural Science Foundation of China (92059207, 92359301, 62027901, 81930053, 81227901, U21A20386); and CAS Youth Interdisciplinary Team (JCTD-2021-08).

Intraoperative molecular imaging of colorectal lung metastases with SGM-101: a feasibility study

PURPOSE

Metastasectomy is a common treatment option for patients with colorectal lung metastases (CLM). Challenges exist with margin assessment and identification of small nodules, especially during minimally invasive surgery. Intraoperative fluorescence imaging has the potential to overcome these challenges. The aim of this study was to assess feasibility of targeting CLM with the carcinoembryonic antigen (CEA) specific fluorescent tracer SGM-101.

METHODS

This was a prospective, open-label feasibility study. The primary outcome was the number of CLM that showed a true positive fluorescence signal with SGM-101. Fluorescence positive signal was defined as a signal-to-background ratio (SBR) ≥ 1.5. A secondary endpoint was the CEA expression in the colorectal lung metastases, assessed with the immunohistochemistry, and scored by the total immunostaining score.

RESULTS

Thirteen patients were included in this study. Positive fluorescence signal with in vivo, back table, and closed-field bread loaf imaging was observed in 31%, 45%, and 94% of the tumors respectively. Median SBRs for the three imaging modalities were 1.00 (IQR: 1.00-1.53), 1.45 (IQR: 1.00-1.89), and 4.81 (IQR: 2.70-7.41). All tumor lesions had a maximum total immunostaining score for CEA expression of 12/12.

CONCLUSION

This study demonstrated the potential of fluorescence imaging of CLM with SGM-101. CEA expression was observed in all tumors, and closed-field imaging showed excellent CEA specific targeting of the tracer to the tumor nodules. The full potential of SGM-101 for in vivo detection of the tracer can be achieved with improved minimal invasive imaging systems and optimal patient selection.

TRIAL REGISTRATION

The study was registered in ClinicalTrial.gov under identifier NCT04737213 at February 2021.

Assessment of the Quality of Patient-Oriented Internet Information on Fluorescence Imaging in Surgery

BACKGROUND

In the digital age, patients are increasingly turning to the Internet to seek medical information to aid in their decision-making process before undergoing medical treatments. Fluorescence imaging is an emerging technological tool that holds promise in enhancing intra-operative decision-making during surgical procedures. This study aims to evaluate the quality of patient information available online regarding fluorescence imaging in surgery and assesses whether it adequately supports informed decision-making.

METHOD

The term "patient information on fluorescence imaging in surgery" was searched on Google. The websites that fulfilled the inclusion criteria were assessed using 2 scoring instruments. DISCERN was used to evaluate the reliability of consumer health information. QUEST was used to assess authorship, tone, conflict of interest and complementarity.

RESULTS

Out of the 50 websites identified from the initial search, 10 fulfilled the inclusion criteria. Only two of these websites were updated in the last two years. The definition of fluorescence imaging was stated in only 50% of the websites. Although all websites mentioned the benefits of fluorescence imaging, none mentioned potential risks. Assessment by DISCERN showed that 30% of the websites were rated low and 70% were rated moderate. With QUEST, the websites demonstrated an average score of 62.5%.

CONCLUSION

This study highlights the importance of providing patients with accurate and balanced information about medical technologies and procedures they may undergo. Fluorescence imaging in surgery is a promising technology that can potentially improve surgical outcomes. However, patients need to be well-informed about its benefits and limitations in order to make informed decisions about their healthcare.

A novel PSMA targeted dual-function near-infrared fluorescence and PET probe for the image-guided surgery and detection of prostate cancer

PURPOSE

Prostate-specific membrane antigen (PSMA) is a promising diagnostic biomarker for prostate cancer (PCa). NYM016, a novel small-molecule PSMA-targeted fluorescence probe for the surgical navigation of PCa, was designed in this work. Furthermore, the potential of the PET agent [68Ga]Ga-NYM016 for the radionuclide imaging of PCa was evaluated.

METHODS

NYM016 was designed with the near-infrared fluorescent group Cyanine 7 (Cy7) and the chelating group NOTA. The radioactive probe [68Ga]Ga-NYM016 was designed and synthesized on the basis of NYM016. The abovementioned probes were assessed in PSMA-positive xenograft-bearing models and patients diagnosed with PCa.

RESULTS

NYM016 obviously aggregated in the tumor site of the mouse model, and its fluorescence intensity was stable within 24 h. NYM016 was well-tolerated, and no adverse events were found in the clinical study. Moreover, it was also observed in the excised lesions from the patient with PCa, and its fluorescence aggregated at the same site where PSMA was highly expressed. In addition, the PSMA xenograft demonstrated intense [68Ga]Ga-NYM016 uptake at 2.5 min after injection. At 3 h after injection, [68Ga]Ga-NYM016 uptake by the PSMA xenograft gradually increased to 6.40 ± 0.19%ID/g, which was higher that by the blocked and negative groups (2.28 ± 0.07%ID/g, P < 0.05; 2.28 ± 0.22%ID/g, P < 0.05). In the clinical study, [68Ga]Ga-NYM016 was well-tolerated and no adverse events were observed. Substantial accumulation was observed in primary and metastatic lesions in a patient with recurrence with the maximum standardized uptake value of 18.93. Meanwhile, negative [68Ga]Ga-NYM016 uptake was observed at the prostate site of a patient with prostatitis.

CONCLUSION

The novel fluorescence probe NYM016 and the radioactive tracer [68Ga]Ga-NYM016 are promising candidates for the surgical navigation and radionuclide imaging of PCa, respectively.

TRIAL REGISTRATION

The clinical evaluation of this study was registered at Clinicaltrial.gov (NCT05623878) on 21 Dec, 2022.

A Concept for Preoperative and Intraoperative Molecular Imaging and Detection for Assessing Extent of Disease of Solid Tumors

The authors propose a concept of "systems engineering," the approach to assessing the extent of diseased tissue (EODT) in solid tumors. We modeled the proof of this concept based on our clinical experience with colorectal carcinoma (CRC) and gastrinoma that included short and long-term survival data of CRC patients. This concept, applicable to various solid tumors, combines resources from surgery, nuclear medicine, radiology, pathology, and oncology needed for preoperative and intraoperative assessments of a patient's EODT. The concept begins with a patient presenting with biopsy-proven cancer. An appropriate preferential locator (PL) is a molecule that preferentially binds to a cancer-related molecular target (i.e., tumor marker) lacking in non-malignant tissue and is the essential element. Detecting the PL after an intravenous injection requires the PL labeling with an appropriate tracer radionuclide, a fluoroprobe, or both. Preoperative imaging of the tracer's signal requires molecular imaging modalities alone or in combination with computerized tomography (CT). These include positron emission tomography (PET), PET/CT, single-photon emission computed tomography (SPECT), SPECT/CT for preoperative imaging, gamma cameras for intraoperative imaging, and gamma-detecting probes for precise localization. Similarly, fluorescent-labeled PLs require appropriate cameras and probes. This approach provides the surgeon with real-time information needed for R0 resection.

Clearly fluorescent delineating ER+ breast tumor incisal edge and identifying tiny metastatic tumor foci at high resolution

Fluorescence-image guided surgery (FGS) can intraoperatively provide real-time visualization of a tumor incisal edge and high-resolution identification of tumor foci to improve treatment outcomes. In this contribution, we report a fluorescent probe NB-TAM based on intramolecularly folded photoinduced electron transfer (PET), which displayed a prominent turn-on response in the near-infrared (NIR) window upon specific interaction with the estrogen receptor (ER). Significantly, NB-TAM could delineate a clear tumor incisal edge (tumor-to-normal tissue ratio > 5) in a 70-min time window, and was successfully used to guide the facile and precise resection of ER+ breast tumors in mice. To our surprise, NB-TAM was found to be capable of identifying very tiny lung metastatic ER+ breast tumor foci (0.4 × 0.3 mm), and this ultrahigh resolution was essential to effectively promote tumor resection precision and early diagnosis of tiny tumors. These results clearly elucidate the promising application of NB-TAM as a diagnostic agent for intraoperative fluorescence imaging of ER+ breast cancer.

Enhancing precision in colorectal cancer surgery: development of an LGR5-targeting RSPO1 peptide mimetic as a contrast agent for intraoperative fluorescence molecular imaging

Colorectal cancer (CRC) is the third most common cancer worldwide. In the United States alone, CRC was responsible for approximately 52,550 deaths in 2023, with an estimated 153,020 new cases. CRC presents with synchronous peritoneal spread in 5-10% of patients, and up to 20-50% of patients with recurrent disease will develop metachronous colorectal cancer peritoneal metastatic (CRC-PM) disease. Eradication of the tumor, tumor margins and microscopic residual disease is paramount, as microscopic residual disease is associated with local recurrences, with 5-year survival rates of less than 35%. The success of resection and reduction of residual disease depends on the accuracy with which cancer cells and normal tissue can be intra-operatively distinguished. Fluorescence Molecular Imaging (IFMI) and tumor-targeted contrast agents represent a promising approach for intraoperative detection and surgical intervention. Proper target selection, the development of scalable imaging agents and enhanced real-time tumor and tumor microenvironment imaging are critical to enabling enhanced surgical resection. LGR5 (leucine-rich repeat-containing G-protein-coupled receptor 5), a colonic crypt stem cell marker and the receptor for the R-spondins (RSPO) in the Wnt signaling pathway, is also expressed on colorectal cancer stem cells (CSC) and on CRC tumors and metastases, suggesting it could be a useful target for imaging of CRC. However, there are numerous diverging reports on the role of LGR5 in CRC therapy and outcomes. Herein, we report on the synthesis and validation of a 37 amino acid RSPO1-mimetic peptide, termed RC18, that was specifically designed to access the R-spondin binding site of LGR5 to potentially be used for interoperative imaging of CRC-PM. The receptor-binding capabilities of the RC18 indicate that direct interactions with LGR5 neither significantly increased LGR5 signaling nor blocked RSPO1 binding and signal transduction, suggesting that the RSPO1-mimetic is functionally inert, making it an attractive contrast agent for intraoperative CRC-PM imaging.

Devices and Methods for Dosimetry of Personalized Photodynamic Therapy of Tumors: A Review on Recent Trends

Significance: Despite the widespread use of photodynamic therapy in clinical practice, there is a lack of personalized methods for assessing the sufficiency of photodynamic exposure on tumors, depending on tissue parameters that change during light irradiation. This can lead to different treatment results. Aim: The objective of this article was to conduct a comprehensive review of devices and methods employed for the implicit dosimetric monitoring of personalized photodynamic therapy for tumors. Methods: The review included 88 peer-reviewed research articles published between January 2010 and April 2024 that employed implicit monitoring methods, such as fluorescence imaging and diffuse reflectance spectroscopy. Additionally, it encompassed computer modeling methods that are most often and successfully used in preclinical and clinical practice to predict treatment outcomes. The Internet search engine Google Scholar and the Scopus database were used to search the literature for relevant articles. Results: The review analyzed and compared the results of 88 peer-reviewed research articles presenting various methods of implicit dosimetry during photodynamic therapy. The most prominent wavelengths for PDT are in the visible and near-infrared spectral range such as 405, 630, 660, and 690 nm. Conclusions: The problem of developing an accurate, reliable, and easily implemented dosimetry method for photodynamic therapy remains a current problem, since determining the effective light dose for a specific tumor is a decisive factor in achieving a positive treatment outcome.

Shining a Light on Venom-Peptide Receptors: Venom Peptides as Targeted Agents for In Vivo Molecular Imaging

Molecular imaging has revolutionised the field of biomedical research by providing a non-invasive means to visualise and understand biochemical processes within living organisms. Optical fluorescent imaging in particular allows researchers to gain valuable insights into the dynamic behaviour of a target of interest in real time. Ion channels play a fundamental role in cellular signalling, and they are implicated in diverse pathological conditions, making them an attractive target in the field of molecular imaging. Many venom peptides exhibit exquisite selectivity and potency towards ion channels, rendering them ideal agents for molecular imaging applications. In this review, we illustrate the use of fluorescently-labelled venom peptides for disease diagnostics and intraoperative imaging of brain tumours and peripheral nerves. Finally, we address challenges for the development and clinical translation of venom peptides as nerve-targeted imaging agents.

Imaging guided adrenalectomy with Indocyanine green fluorescence in a dog with a pheochromocytoma

IMPORTANCE

This case report presents the successful surgical removal of a pheochromocytoma in a dog using indocyanine green (ICG) fluorescence imaging.

CASE PRESENTATION

A 10-year-old, 6.87 kg, spayed female poodle was referred for an abdominal mass and eight episodes of vomiting. Computed tomography revealed masses in the spleen and left adrenal gland. Based on the plasma normetanephrine levels, the patient was diagnosed with pheochromocytoma. Subsequently, a total splenectomy and left adrenalectomy were performed. A dose of 5 mg/kg ICG was administered intravenously 24 h prior to surgery. Using ICG allowed visualization of tumor margins, aiding in complete resection and minimizing anesthesia-related risks.

CONCLUSIONS AND RELEVANCE

No evidence of recurrence or metastasis has been observed for 12 months. To our knowledge, this is the first report of the surgical removal of a pheochromocytoma using intraoperative ICG imaging in veterinary medicine. This case highlights the efficacy of ICG fluorescence imaging as a valuable tool for the surgical management of adrenal tumors in veterinary medicine.

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.