Improved Tumor Discrimination and Shortened Administration-to-Imaging Times in Fluorescence Guided Surgery Through Paired-Agent Protocols (original) (raw)

Receptor-Targeted Fluorescence-Guided Surgery With Low Molecular Weight Agents

Frontiers in Oncology, 2021

Cancer surgery remains the primary treatment option for most solid tumors and can be curative if all malignant cells are removed. Surgeons have historically relied on visual and tactile cues to maximize tumor resection, but clinical data suggest that relapse occurs partially due to incomplete cancer removal. As a result, the introduction of technologies that enhance the ability to visualize tumors in the operating room represents a pressing need. Such technologies have the potential to revolutionize the surgical standard-of-care by enabling real-time detection of surgical margins, subclinical residual disease, lymph node metastases and synchronous/metachronous tumors. Fluorescence-guided surgery (FGS) in the near-infrared (NIRF) spectrum has shown tremendous promise as an intraoperative imaging modality. An increasing number of clinical studies have demonstrated that tumor-selective FGS agents can improve the predictive value of fluorescence over non-targeted dyes. Whereas NIRF-labe...

Prediction of optimal contrast times post-imaging agent administration to inform personalized fluorescence-guided surgery

Journal of Biomedical Optics, 2020

Significance: Fluorescence guidance in cancer surgery (FGS) using molecular-targeted contrast agents is accelerating, yet the influence of individual patients' physiology on the optimal time to perform surgery post-agent-injection is not fully understood. Aim: Develop a mathematical framework and analytical expressions to estimate patient-specific time-to-maximum contrast after imaging agent administration for single-and paired-agent (coadministration of targeted and control agents) protocols. Approach: The framework was validated in mouse subcutaneous xenograft studies for three classes of imaging agents: peptide, antibody mimetic, and antibody. Analytical expressions estimating time-to-maximum-tumor-discrimination potential were evaluated over a range of parameters using the validated framework for human cancer parameters. Results: Correlations were observed between simulations and matched experiments and metrics of tumor discrimination potential (p < 0.05). Based on human cancer physiology, times-to-maximum contrast for peptide and antibody mimetic agents were <200 min, >15 h for antibodies, on average. The analytical estimates of time-to-maximum tumor discrimination performance exhibited errors of <10% on average, whereas patient-to-patient variance is expected to be greater than 100%. Conclusion: We demonstrated that analytical estimates of time-to-maximum contrast in FGS carried out patient-to-patient can outperform the population average time-to-maximum contrast used currently in clinical trials. Such estimates can be made with preoperative DCE-MRI (or similar) and knowledge of the targeted agent's binding affinity.

Exploring the role of fluorescence image-guided surgery (FIGS) in surgical oncology (nuclear medicine)

PROCEEDINGS OF INTERNATIONAL CONFERENCE ON NUCLEAR SCIENCE, TECHNOLOGY, AND APPLICATION 2020 (ICONSTA 2020), 2021

Surgical resection, in combination with or without chemotherapy/radiotherapy remains the primary treatment option for cancer patients. The main goal of surgery is to achieve complete removal of all cancerous tissues and improve safety by avoiding unnecessary destruction to normal cells. Unfortunately, the surgical margin positivity rate has not been improved significantly over the past few years despite the extensive use of preoperative imaging modalities, including single-photon emission tomography (SPECT) and positron emission tomography (PET). Surgery that is guided by fluorescence imaging, known as fluorescence image-guided surgery (FIGS) has the potential to revolutionize and address the issues associating with cancer surgery. Consequently, there is a growing interest in the promising impact of FIGS molecular navigation on surgical outcomes. In clinical settings, the application of FIGS involves co-injection of 2 singlelabeled targeting agents, 1 agent carrying a nuclear label and 1 agent carrying a fluorescent probe. Alternatively, the nuclear and fluorescent moiety can both be conjugated to 1 targeting molecule (called as hybrid molecule), offering more valuable benefits than the utilization of SPECT/PET tracer or fluorescence alone. It seems, the advancement of hybrid molecules makes the future of nuclear molecular imaging is becoming ever more interesting and so different from the past. Although considerable progresses have been made, the development of FIGS technology still needs further exploration and advancement. In this review, we describe recent developments of FIGS in the field of surgical oncology, its role in complementing the use of radiotracers in nuclear medicine, and a perspective on the potential of future hybrid SPECT/PET and fluorescence imaging.

EpCAM as multi-tumour target for near-infrared fluorescence guided surgery

BMC cancer, 2016

Evaluation of resection margins during cancer surgery can be challenging, often resulting in incomplete tumour removal. Fluorescence-guided surgery (FGS) aims to aid the surgeon to visualize tumours and resection margins during surgery. FGS relies on a clinically applicable imaging system in combination with a specific tumour-targeting contrast agent. In this study EpCAM (epithelial cell adhesion molecule) is evaluated as target for FGS in combination with the novel Artemis imaging system. The NIR fluorophore IRDye800CW was conjugated to the well-established EpCAM specific monoclonal antibody 323/A3 and an isotype IgG1 as control. The anti-EpCAM/800CW conjugate was stable in serum and showed preserved binding capacity as evaluated on EpCAM positive and negative cell lines, using flow cytometry and cell-based plate assays. Four clinically relevant orthotopic tumour models, i.e. colorectal cancer, breast cancer, head and neck cancer, and peritonitis carcinomatosa, were used to evaluat...

Surgery with molecular fluorescence imaging using activatable cell-penetrating peptides decreases residual cancer and improves survival

Proceedings of the National Academy of Sciences, 2010

The completeness of tumor removal during surgery is dependent on the surgeon's ability to differentiate tumor from normal tissue using subjective criteria that are not easily quantifiable. A way to objectively assess tumor margins during surgery in patients would be of great value. We have developed a method to visualize tumors during surgery using activatable cell-penetrating peptides (ACPPs), in which the fluorescently labeled, polycationic cell-penetrating peptide (CPP) is coupled via a cleavable linker to a neutralizing peptide. Upon exposure to proteases characteristic of tumor tissue, the linker is cleaved, dissociating the inhibitory peptide and allowing the CPP to bind to and enter tumor cells. In mice, xenografts stably transfected with green fluorescent protein show colocalization with the Cy5-labeled ACPPs. In the same mouse models, Cy5-labeled free ACPPs and ACPPs conjugated to dendrimers (ACPPDs) delineate the margin between tumor and adjacent tissue, resulting in improved precision of tumor resection. Surgery guided by ACPPD resulted in fewer residual cancer cells left in the animal after surgery as measured by Alu PCR. A single injection of ACPPD dually labeled with Cy5 and gadolinium chelates enabled preoperative wholebody tumor detection by MRI, intraoperative guidance by real-time fluorescence, intraoperative histological analysis of margin status by fluorescence, and postoperative MRI tumor quantification. Animals whose tumors were resected with ACPPD guidance had better long-term tumor-free survival and overall survival than animals whose tumors were resected with traditional bright-field illumination only.

Intraoperative imaging-guided cancer surgery: from current fluorescence molecular imaging methods to future multi-modality imaging technology

Theranostics, 2014

Cancer is a major threat to human health. Diagnosis and treatment using precision medicine is expected to be an effective method for preventing the initiation and progression of cancer. Although anatomical and functional imaging techniques such as radiography, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) have played an important role for accurate preoperative diagnostics, for the most part these techniques cannot be applied intraoperatively. Optical molecular imaging is a promising technique that provides a high degree of sensitivity and specificity in tumor margin detection. Furthermore, existing clinical applications have proven that optical molecular imaging is a powerful intraoperative tool for guiding surgeons performing precision procedures, thus enabling radical resection and improved survival rates. However, detection depth limitation exists in optical molecular imaging methods and further breakthroughs from optical to mul...

Intraoperative Near-Infrared Fluorescence Tumor Imaging with Vascular Endothelial Growth Factor and Human Epidermal Growth Factor Receptor 2 Targeting …

Journal of Nuclear …, 2011

Fluorescence imaging is currently attracting much interest as a method for intraoperative tumor detection, but most current tracers lack tumor specificity. Therefore, this technique can be further improved by tumor-specific detection. With tumortargeted antibodies bound to a radioactive label, tumor-specific SPECT or PET is feasible in the clinical setting. The aim of the present study was to apply antibody-based tumor detection to intraoperative optical imaging, using preclinical in vivo mouse models. Methods: Anti-vascular endothelial growth factor (VEGF) antibody bevacizumab and anti-human epidermal growth factor receptor (HER) 2 antibody trastuzumab were labeled with the near-infrared (NIR) fluorescence dye IRDye 800CW. Tumor uptake of the fluorescent tracers and their 89 Zr-labeled radioactive counterparts for PET was determined in human xenograft-bearing athymic mice during 1 wk after tracer injection, followed by ex vivo biodistribution and pathologic examination. Intraoperative imaging of fluorescent VEGF-or HER2-positive tumor lesions was performed in subcutaneous tumors and in intraperitoneal dissemination tumor models. Results: Tumorto-background ratios, with fluorescent imaging, were 1.93 6 0.40 for bevacizumab and 2.92 6 0.29 for trastuzumab on day 6 after tracer injection. Real-time intraoperative imaging detected tumor lesions at even the submillimeter level in intraperitoneal dissemination tumor models. These results were supported by standard histology, immunohistochemistry, and fluorescence microscopy analyses. Conclusion: NIR fluorescence-labeled antibodies targeting VEGF or HER2 can be used for highly specific and sensitive detection of tumor lesions in vivo. These preclinical findings encourage future clinical studies with NIR fluorescence-labeled tumor-specific antibodies for intraoperative-guided surgery in cancer patients.

Intraoperative Near-Infrared Fluorescence Tumor Imaging with Vascular Endothelial Growth Factor and Human Epidermal Growth Factor Receptor 2 Targeting Antibodies

Journal of Nuclear Medicine, 2011

Fluorescence imaging is currently attracting much interest as a method for intraoperative tumor detection, but most current tracers lack tumor specificity. Therefore, this technique can be further improved by tumor-specific detection. With tumortargeted antibodies bound to a radioactive label, tumor-specific SPECT or PET is feasible in the clinical setting. The aim of the present study was to apply antibody-based tumor detection to intraoperative optical imaging, using preclinical in vivo mouse models. Methods: Anti-vascular endothelial growth factor (VEGF) antibody bevacizumab and anti-human epidermal growth factor receptor (HER) 2 antibody trastuzumab were labeled with the near-infrared (NIR) fluorescence dye IRDye 800CW. Tumor uptake of the fluorescent tracers and their 89 Zr-labeled radioactive counterparts for PET was determined in human xenograft-bearing athymic mice during 1 wk after tracer injection, followed by ex vivo biodistribution and pathologic examination. Intraoperative imaging of fluorescent VEGF-or HER2-positive tumor lesions was performed in subcutaneous tumors and in intraperitoneal dissemination tumor models. Results: Tumorto-background ratios, with fluorescent imaging, were 1.93 6 0.40 for bevacizumab and 2.92 6 0.29 for trastuzumab on day 6 after tracer injection. Real-time intraoperative imaging detected tumor lesions at even the submillimeter level in intraperitoneal dissemination tumor models. These results were supported by standard histology, immunohistochemistry, and fluorescence microscopy analyses. Conclusion: NIR fluorescence-labeled antibodies targeting VEGF or HER2 can be used for highly specific and sensitive detection of tumor lesions in vivo. These preclinical findings encourage future clinical studies with NIR fluorescence-labeled tumor-specific antibodies for intraoperative-guided surgery in cancer patients.

Fluorescence molecular imaging systems for intraoperative image-guided surgery

Applied Spectroscopy Reviews, 2017

Despite advances in diagnostic and therapeutic technology of human diseases, cancer remains among the leading causes of morbidity and mortality worldwide. The development of molecular imaging has made it possible to diagnose and treat cancer at early stages, which increases the likelihood of survival. Nuclear medicine has played a key role in diagnosis and staging of human malignancy. However, most imaging technology can only be used in the preoperative diagnosis stage, and these methods are time consuming and often expose patients to a high amount of radiation. Combined with appropriate contrast agents, fluorescence molecular imaging is an easy-to-use imaging tool that can be

Development of a drug–device combination for fluorescence-guided surgery in neuroendocrine tumors

Journal of Biomedical Optics, 2020

Significance: The use of cancer-targeted contrast agents in fluorescence-guided surgery (FGS) has the potential to improve intraoperative visualization of tumors and surgical margins. However, evaluation of their translational potential is challenging. Aim: We examined the utility of a somatostatin receptor subtype-2 (SSTR2)-targeted fluorescent agent in combination with a benchtop near-infrared fluorescence (NIRF) imaging system to visualize mouse xenografts under conditions that simulate the clinical FGS workflow for open surgical procedures. Approach: The dual-labeled somatostatin analog, 67 Ga-MMC(IR800)-TOC, was injected into mice (n ¼ 24) implanted with SSTR2-expressing tumors and imaged with the customized OnLume NIRF imaging system (Madison, Wisconsin). In vivo and ex vivo imaging were performed under ambient light. The optimal dose (0.2, 0.5, and 2 nmol) and imaging time point (3, 24, 48, and 72 h) were determined using contrast-to-noise ratio (CNR) as the image quality parameter. Video captures of tumor resections were obtained to provide an FGS readout that is representative of clinical utility. Finally, a log-transformed linear regression model was fitted to assess congruence between fluorescence readouts and the underlying drug distribution. Results: The drug-device combination provided high in vivo and ex vivo contrast (CNRs > 3, except lung at 3 h) at all time points with the optimal dose of 2 nmol. The optimal imaging time point was 24-h post-injection, where CNRs > 6.5 were achieved in tissues of interest (i.e., pancreas, small intestine, stomach, and lung). Intraoperative FGS showed excellent utility for examination of the tumor cavity pre-and post-resection. The relationship between fluorescence readouts and gamma counts was linear and strongly correlated (n ¼ 334, R 2 ¼ 0.71; r ¼ 0.84; P < 0.0001). Conclusion: The innovative OnLume NIRF imaging system enhanced the evaluation of 67 Ga-MMC(IR800)-TOC in tumor models. These components comprise a promising drugdevice combination for FGS in patients with SSTR2-expressing tumors.