In JoVE (1)

Other Publications (35)

Articles by Gooitzen M. van Dam in JoVE

 JoVE Medicine

Multispectral Real-time Fluorescence Imaging for Intraoperative Detection of the Sentinel Lymph Node in Gynecologic Oncology

1Department of Surgery, Division of Surgical Oncology, University Medical Center Groningen, 2Helmholtz Zentrum, Technical University Munich, 3Department of Obstetrics and Gynaecology, University Medical Center Groningen

JoVE 2225

Other articles by Gooitzen M. van Dam on PubMed

Spatiotemporal Expression of Heme Oxygenase-1 Detected by in Vivo Bioluminescence After Hepatic Ischemia in HO-1/Luc Mice

Liver Transplantation : Official Publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society. Nov, 2006  |  Pubmed ID: 17058249

Upregulation of heme oxygenase-1 (HO-1) has been proposed as a critical mechanism protecting against cellular stress during liver transplantation, providing a potential target for new therapeutic interventions. We investigated the feasibility of in vivo bioluminescence imaging (BLI) to noninvasively quantify the spatiotemporal expression of HO-1 after warm hepatic ischemia in living animals. Luciferase activity was measured by BLI as an index of HO-1 transcription in transgenic reporter mice (Ho1-luc) at standardized time points after 60 minutes of warm hepatic ischemia. HO-1 mRNA levels were measured in postischemic livers of mice sacrificed at the same time points in separate experiments. Bioluminescent signals from postischemic liver lobes were first detected at 3 hours after reperfusion. Peak levels were reached at 9 hours, after which bioluminescent activity declined and returned to baseline values at 48 hours after reperfusion. Upregulation of HO-1 as detected by in vivo BLI was preceded by increased HO-1 mRNA expression and confirmed by enhanced immunohistochemical staining of hepatocytes. In conclusion, this study shows that in vivo BLI allows a sensitive assessment of HO-1 expression after hepatic ischemia in living animals. The capability of whole-body temporal imaging of HO-1 expression provides a valuable tool in the development of novel strategies to modulate HO-1 expression in liver transplantation.

Oesophageal Cancer in The Netherlands: Increasing Incidence and Mortality but Improving Survival

European Journal of Cancer (Oxford, England : 1990). Jun, 2007  |  Pubmed ID: 17512189

Oesophageal cancer is highly lethal with a 5-year relative survival of 10-15%. An increasing incidence has been reported for several parts of the Western world. We studied time trends in incidence, mortality and survival for oesophageal cancer in the Netherlands during 1989-2003.

Current Relevance of Cervical Ultrasonography in Staging Cancer of the Esophagus and Gastroesophageal Junction

European Journal of Radiology. Jul, 2008  |  Pubmed ID: 17681735

To evaluate the value of external ultrasonography (US) of the neck in current dedicated preoperative staging of patients with cancer of the esophagus and gastroesophageal junction (GEJ).

Better Assessment of Nodal Metastases by PET/CT Fusion Compared to Side-by-side PET/CT in Oesophageal Cancer

Anticancer Research. May-Jun, 2008  |  Pubmed ID: 18630473

Recently, positron emission tomography/computed tomography (PET/CT) has been introduced in the staging of oesophageal cancer. The impact of PET/CT fusion in comparison with side-by-side PET/CT in these tumours, was analyzed.

Current Imaging Modalities to Visualize Vulnerability Within the Atherosclerotic Carotid Plaque

Journal of Vascular Surgery : Official Publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter. Dec, 2008  |  Pubmed ID: 18804942

There is increasing evidence that plaque vulnerability, rather than the degree of stenosis, is important in predicting the occurrence of subsequent cerebral ischemic events in patients with carotid artery stenosis. The many imaging modalities currently available have different properties with regard to the visualization of the extent of vulnerability in carotid plaque formation.

Potent Systemic Anticancer Activity of Adenovirally Expressed EGFR-selective TRAIL Fusion Protein

Molecular Therapy : the Journal of the American Society of Gene Therapy. Dec, 2008  |  Pubmed ID: 18813279

Previously, we demonstrated potent tumor cell-selective pro-apoptotic activity of scFv425:sTRAIL, a recombinant fusion protein comprised of EGFR-directed antibody fragment (scFv425) genetically fused to human soluble TNF-related apoptosis-inducing ligand (sTRAIL). Here, we report on the promising therapeutic systemic tumoricidal activity of scFv425:sTRAIL when produced by the replication-deficient adenovirus Ad-scFv425:sTRAIL. In vitro treatment of EGFR-positive tumor cells with Ad-scFv425:sTRAIL resulted in the potent induction of apoptosis of not only infected tumor cells, but importantly also of up to 60% of noninfected EGFR-positive tumor cells. A single intraocular injection of Ad-scFv425:sTRAIL in tumor-free nu/nu mice resulted in predominant liver infection and concomitant high blood plasma levels of scFv425:sTRAIL. These mice showed no sign of Ad-scFv425:sTRAIL-related liver toxicity. Identical treatment of mice with established intraperitoneal renal cell carcinoma xenografts resulted in rapid and massive tumor load reduction and subsequent long-term survival. Taken together, adenoviral-mediated in vivo production of scFv425:sTRAIL may be exploitable for systemic treatment of EGFR-positive cancer.

Real Time Noninvasive Monitoring of Contaminating Bacteria in a Soft Tissue Implant Infection Model

Journal of Biomedical Materials Research. Part B, Applied Biomaterials. Jan, 2009  |  Pubmed ID: 18618733

Infection is the main cause of biomaterials-related failure. A simple technique to test in-vivo new antimicrobial and/or nonadhesive implant coatings is unavailable. Current in vitro methods for studying bacterial adhesion and growth on biomaterial surfaces lack the influence of the host immune system. Most in vivo methods to study biomaterials-related infections routinely involve implant-removal, preventing comprehensive longitudinal monitoring. In vivo imaging circumvents these drawbacks and is based on the use of noninvasive optical imaging of bioluminescent bacteria. Staphylococcus aureus Xen29 is genetically modified to be stably bioluminescent, by the introduction of a modified full lux operon onto its chromosome. Surgical meshes with adhering S. aureus Xen29 were implanted in mice and bacterial growth and spread into the surrounding tissue was monitored longitudinally from bioluminescence with a highly sensitive CCD camera. Distinct spatiotemporal bioluminescence patterns, extending beyond the mesh area into surrounding tissues were observed. After 10 days, the number of living organisms isolated from explanted meshes was found to correlate with bioluminescence prior to sacrifice of the animals. Therefore, it is concluded that in vivo imaging using bioluminescent bacteria is ideally suited to study antimicrobial coatings taking into account the host immune system. In addition, longitudinal monitoring of infection in one animal will significantly reduce the number of experiments and animals.

Intraoperative Ischemia of the Distal End of Colon Anastomoses As Detected with Visible Light Spectroscopy Causes Reduction of Anastomotic Strength

The Journal of Surgical Research. Apr, 2009  |  Pubmed ID: 18952233

To explore new methods for intraoperative evaluation of tissue oxygenation, we evaluated the use of visible light spectroscopy as a predictor of anastomotic strength in an experimental model with ischemic murine colon anastomoses.

Antimicrobial Effects of an NO-releasing Poly(ethylene Vinylacetate) Coating on Soft-tissue Implants in Vitro and in a Murine Model

Acta Biomaterialia. Jul, 2009  |  Pubmed ID: 19251498

Infection of surgical meshes used in abdominal wall reconstructions often leads to removal of the implant and increases patient morbidity due to repetitive operations and hospital administrations. Treatment with antibiotics is ineffective due to the biofilm mode of growth of the infecting bacteria and bears the risk of inducing antibiotic resistance. Hence there is a need for alternative methods to prevent and treat mesh infection. Nitric oxide (NO)-releasing coatings have been demonstrated to possess bactericidal properties in vitro. It is the aim of this study to assess possible benefits of a low concentration NO-releasing carbon-based coating on monofilament polypropylene meshes with respect to infection control in vitro and in vivo. When applied on surgical meshes, NO-releasing coatings showed significant bactericidal effect on in vitro biofilms of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and CNS. However, using bioluminescent in vivo imaging, no beneficial effects of this NO-releasing coating on subcutaneously implanted surgical meshes in mice could be observed.

Hypothesis: Using the Warburg Effect Against Cancer by Reducing Glucose and Providing Lactate

Medical Hypotheses. Jul, 2009  |  Pubmed ID: 19264418

The avid consumption of glucose with concomitant lactate production by malignant cells, even under aerobic conditions, is called the Warburg effect, or aerobic glycolysis. This metabolic state is a final common pathway that apparently serves various invasive purposes. As most invasive tumours display the Warburg effect, this has proven of great clinical importance in detecting malignancies with 18-fluorine 2-deoxyglucose positron emission tomography (FDG-PET) scans. However, using the Warburg effect to target malignancies has proven more difficult. Since hypoglycaemia has been shown to be tumouricidal for cancers that display the Warburg effect, various schemes to block glucose utilization have been investigated. But in vivo it is difficult to selectively target glucose utilization in malignant cells without harming normal cells. Cancer cells produce large amounts of lactate under the Warburg effect, without fully oxidizing it to CO(2). In contrast normal cells can completely oxidize lactate under aerobic conditions. Recent studies have demonstrated that vital organs such as the brain, heart, liver, kidneys and muscle are capable of oxidizing lactate as a fuel alternative to glucose. It has also been shown that during hypoglycaemia intravenous lactate can serve as a salvage fuel in man. Other clinical studies showed that patients can effectively metabolize large amounts of exogenous lactate. All this appears to reflect the recently recognized major physiological role of lactate as a glucose alternative. Consequently, lactate is the most logical candidate to serve as a salvage fuel when local or systemic hypoglycemia is induced. Thus, we hypothesize that the combination of hypoglycaemia induced by insulin and concomitant lactate administration will selectively suppress cancers manifesting the Warburg effect, since such cancers will have great difficulty in metabolizing lactate. This metabolic therapy could be modulated in many ways both in amplitude, in duration and in timing with respect to other therapies. The validated isolated limb perfusion (ILP) model for sarcoma appears an attractive model to evaluate local therapy with insulin and lactate and test its (adjuvant) tumouricidal effects in animals and man. Such effects could be evaluated with modern metabolic detection techniques such as FDG-PET and magnetic resonance imaging in local models both in animals and humans. Subsequently the systemic effects of hypoglycaemia combined with sodium lactate administration could be evaluated.

Images in Cardiovascular Medicine. Multispectral Near-infrared Fluorescence Molecular Imaging of Matrix Metalloproteinases in a Human Carotid Plaque Using a Matrix-degrading Metalloproteinase-sensitive Activatable Fluorescent Probe

Circulation. May, 2009  |  Pubmed ID: 19470893

Obtaining Adequate Surgical Margins in Breast-conserving Therapy for Patients with Early-stage Breast Cancer: Current Modalities and Future Directions

Annals of Surgical Oncology. Oct, 2009  |  Pubmed ID: 19609829

Inadequate surgical margins represent a high risk for adverse clinical outcome in breast-conserving therapy (BCT) for early-stage breast cancer. The majority of studies report positive resection margins in 20% to 40% of the patients who underwent BCT. This may result in an increased local recurrence (LR) rate or additional surgery and, consequently, adverse affects on cosmesis, psychological distress, and health costs. In the literature, various risk factors are reported to be associated with positive margin status after lumpectomy, which may allow the surgeon to distinguish those patients with a higher a priori risk for re-excision. However, most risk factors are related to tumor biology and patient characteristics, which cannot be modified as such. Therefore, efforts to reduce the number of positive margins should focus on optimizing the surgical procedure itself, because the surgeon lacks real-time intraoperative information on the presence of positive resection margins during breast-conserving surgery. This review presents the status of pre- and intraoperative modalities currently used in BCT. Furthermore, innovative intraoperative approaches, such as positron emission tomography, radioguided occult lesion localization, and near-infrared fluorescence optical imaging, are addressed, which have to prove their potential value in improving surgical outcome and reducing the need for re-excision in BCT.

PET/SPECT Imaging: from Carotid Vulnerability to Brain Viability

European Journal of Radiology. Apr, 2010  |  Pubmed ID: 19246168

Current key issues in ischemic stroke are related to carotid plaque vulnerability, brain viability, and timing of intervention. The treatment of ischemic stroke has evolved into urgent active interventions, as 'time is brain'. Functional imaging such as positron emission tomography (PET)/single photon emission computed tomography (SPECT) could improve selection of patients with a vulnerable plaque and evaluation of brain viability in ischemic stroke.

Spatiotemporal Progression of Localized Bacterial Peritonitis Before and After Open Abdomen Lavage Monitored by in Vivo Bioluminescent Imaging

Surgery. Jan, 2010  |  Pubmed ID: 19733882

Bacterial peritonitis is a life-threatening abdominal infection associated with high morbidity and mortality. The rat is a popular animal model for studying peritonitis and its treatment, but longitudinal monitoring of the progression of peritonitis in live animals has been impossible until now and thus required a large number of animals. Our objective was to develop a noninvasive in vivo imaging technique to monitor the spatiotemporal spread of bacterial peritonitis.

Spectroscopy to Improve Identification of Vulnerable Plaques in Cardiovascular Disease

The International Journal of Cardiovascular Imaging. Jan, 2010  |  Pubmed ID: 19760516

Many apparent healthy persons die from cardiovascular disease, despite major advances in prevention and treatment of cardiovascular disease. Traditional cardiovascular risk factors are able to predict cardiovascular events in the long run, but fail to assess current disease activity or nearby cardiovascular events. There is a clear relation between the occurrence of cardiovascular events and the presence of so-called vulnerable plaques. These vulnerable plaques are characterized by active inflammation, a thin cap and a large lipid pool. Spectroscopy is an optical imaging technique which depicts the interaction between light and tissues, and thereby shows the biochemical composition of tissues. In recent years, impressive advances have been made in spectroscopy technology and intravascular spectroscopy is able to assess the composition of plaques of interest and thereby to identify and actually quantify plaque vulnerability. This review summarizes the current evidence for spectroscopy as a measure of plaque vulnerability and discusses the potential role of intravascular spectroscopic imaging techniques.

In Vivo Evaluation of Bacterial Infection Involving Morphologically Different Surgical Meshes

Annals of Surgery. Jan, 2010  |  Pubmed ID: 19864938

To study the influence of morphology of surgical meshes on the course of bacterial infection under the influence of the host immune system in an in vivo chronic bacterial infection model.

A Critical Appraisal of Circumferential Resection Margins in Esophageal Carcinoma

Annals of Surgical Oncology. Mar, 2010  |  Pubmed ID: 19924487

In esophageal cancer, circumferential resection margins (CRMs) are considered to be of relevant prognostic value, but a reliable definition of tumor-free CRM is still unclear. The aim of this study was to appraise the clinical prognostic value of microscopic CRM involvement and to determine the optimal limit of CRM.

The Potential for Bio-optical Imaging of Biomaterial-associated Infection in Vivo

Biomaterials. Mar, 2010  |  Pubmed ID: 19969345

This review presents the current state of Bioluminescence and Fluorescent Imaging technologies (BLI and FLI) as applied to Biomaterial-Associated Infections (BAI). BLI offers the opportunity to observe the in vivo course of BAI in small animals without the need to sacrifice animals at different time points after the onset of infection. BLI is highly dependent on the bacterial cell metabolism which makes BLI a strong reporter of viable bacterial presence. Fluorescent sources are generally more stable than bioluminescent ones and specifically targeted, which renders the combination of BLI and FLI a promising tool for imaging BAI. The sensitivity and spatial resolution of both imaging tools are, however, dependent on the imaging system used and the tissue characteristics, which makes the interpretation of images, in terms of the location and shape of the illuminating source, difficult. Tomographic reconstruction of the luminescent source is possible in the most modern instruments, enabling exact localization of a colonized implant material, spreading of infecting organisms in surrounding tissue and immunological tissue reactions. BLI studies on BAI have successfully distinguished between different biomaterials with respect to the development and clearance of BAI in vivo, simultaneously reducing animal use and experimental variation. It is anticipated that bio-optical imaging will become an indispensable technology for the in vivo evaluation of antimicrobial coatings.

Limited Value of Staging Squamous Cell Carcinoma of the Anal Margin and Canal Using the Sentinel Lymph Node Procedure: A Prospective Study with Long-Term Follow-Up

Annals of Surgical Oncology. Apr, 2010  |  Pubmed ID: 20390456

BACKGROUND: Selection of patients with anal cancer for groin irradiation is based on tumor size, palpation, ultrasound, and fine needle cytology. Current staging of anal cancer may result in undertreatment in small tumors and overtreatment of large tumors. This study reports the feasibility of the sentinel lymph node biopsy (SLNB) in patients with anal cancer and whether this improves the selection for inguinal radiotherapy. METHODS: A total of 50 patients with squamous anal cancer were evaluated prospectively. Patients without a SLNB (n = 29) received irradiation of the inguinal lymph nodes based on lymph node status, tumor size, and location of the primary tumor. Inguinal irradiation treatment in patients with a SLNB was based on the presence of metastases in the SLN. RESULTS: SLNs were found in all 21 patients who underwent a SLNB. There were 5 patients (24%) who had complications after SLNB and 7 patients (33%) who had a positive SLN and received inguinal irradiation. However, 2 patients with a tumor-free SLN and no inguinal irradiation developed lymph node metastases after 12 and 24 months, respectively. CONCLUSIONS: We conclude that SLNB in anal cancer is technically feasible. SLNB can identify those patients who would benefit from refrain of inguinal irradiation treatment and thereby reducing the incidence of unnecessary inguinal radiotherapy. However, because of the occurrence of inguinal lymph node metastases after a tumor-negative SLNB, introduction of this procedure as standard of care in all patients with anal carcinoma should be done with caution to avoid undertreatment of patient who otherwise would benefit from inguinal radiotherapy.

Prognostic Factors and Patterns of Recurrence in Esophageal Cancer Assert Arguments for Extended Two-field Transthoracic Esophagectomy

American Journal of Surgery. Oct, 2010  |  Pubmed ID: 20409512

High recurrence rates determine the dismal outcome in esophageal cancer. We reviewed our experiences and defined prognostic factors and patterns of recurrences after curatively intended transthoracic esophagectomy.

The Risk of Biomaterial-associated Infection After Revision Surgery Due to an Experimental Primary Implant Infection

Biofouling. Oct, 2010  |  Pubmed ID: 20737327

The fate of secondary biomaterial implants was determined by bio-optical imaging and plate counting, after antibiotic treatment of biomaterials-associated-infection (BAI) and surgical removal of an experimentally infected, primary implant. All primary implants and tissue samples from control mice showed bioluminescence and were culture-positive. In an antibiotic treated group, no bioluminescence was detected and only 20% of all primary implants and no tissue samples were culture-positive. After revision surgery, bioluminescence was detected in all control mice. All the implants and 80% of all tissue samples were culture-positive. In contrast, in the antibiotic treated group, 17% of all secondary implants and 33% of all tissue samples were culture-positive, despite antibiotic treatment. The study illustrates that due to the BAI of a primary implant, the infection risk of biomaterial implants is higher in revision surgery than in primary surgery, emphasizing the need for full clearance of the infection, as well as from surrounding tissues prior to implantation of a secondary implant.

Limited Value of Staging Squamous Cell Carcinoma of the Anal Margin and Canal Using the Sentinel Lymph Node Procedure: a Prospective Study with Long-term Follow-up

Annals of Surgical Oncology. Oct, 2010  |  Pubmed ID: 20865825

Selection of patients with anal cancer for groin irradiation is based on tumor size, palpation, ultrasound, and fine needle cytology. Current staging of anal cancer may result in undertreatment in small tumors and overtreatment of large tumors. This study reports the feasibility of the sentinel lymph node biopsy (SLNB) in patients with anal cancer and whether this improves the selection for inguinal radiotherapy.

Current Concepts and Future Perspectives on Surgical Optical Imaging in Cancer

Journal of Biomedical Optics. Nov-Dec, 2010  |  Pubmed ID: 21198198

There are vibrant developments of optical imaging systems and contrast-enhancing methods that are geared to enhancing surgical vision and the outcome of surgical procedures. Such optical technologies designed for intraoperative use can offer high integration in the operating room compared to conventional radiological modalities adapted to intraoperative applications. Simple fluorescence epi-illumination imaging, in particular, appears attractive but may lead to inaccurate observations due to the complex nature of photon-tissue interaction. Of importance therefore are emerging methods that account for the background optical property variation in tissues and can offer accurate, quantitative imaging that eliminates the appearance of false negatives or positives. In parallel, other nonfluorescent optical imaging methods are summarized and overall progress in surgical optical imaging applications is outlined. Key future directions that have the potential to shift the paradigm of surgical health care are also discussed.

Intraoperative Multispectral Fluorescence Imaging for the Detection of the Sentinel Lymph Node in Cervical Cancer: a Novel Concept

Molecular Imaging and Biology : MIB : the Official Publication of the Academy of Molecular Imaging. Oct, 2011  |  Pubmed ID: 20835767

Real-time intraoperative near-infrared fluorescence (NIRF) imaging is a promising technique for lymphatic mapping and sentinel lymph node (SLN) detection. The purpose of this technical feasibility pilot study was to evaluate the applicability of NIRF imaging with indocyanin green (ICG) for the detection of the SLN in cervical cancer.

Adequate Debridement and Drainage of the Mediastinum Using Open Thoracotomy or Video-assisted Thoracoscopic Surgery for Boerhaave's Syndrome

Surgical Endoscopy. Aug, 2011  |  Pubmed ID: 21359901

Boerhaave's syndrome has a high mortality rate (14-40%). Surgical treatment varies from a minimal approach consisting of adequate debridement with drainage of the mediastinum and pleural cavity to esophageal resection. This study compared the results between a previously preferred open minimal approach and a video-assisted thoracoscopic surgery (VATS) procedure currently considered the method of choice.

Lower Rate of Major Bile Duct Injury and Increased Intraoperative Management of Common Bile Duct Stones After Implementation of Routine Intraoperative Cholangiography

Journal of the American College of Surgeons. Aug, 2011  |  Pubmed ID: 21459631

Our university medical center is the only center in The Netherlands that has adopted a policy of routine intraoperative cholangiography (IOC) during cholecystectomy. This study aimed to describe the rate of bile duct injury (BDI) and management of common bile duct (CBD) stones before and after implementation of a routine IOC policy.

Selecting Potential Targetable Biomarkers for Imaging Purposes in Colorectal Cancer Using TArget Selection Criteria (TASC): A Novel Target Identification Tool

Translational Oncology. 2011  |  Pubmed ID: 21461170

Peritoneal carcinomatosis (PC) of colorectal origin is associated with a poor prognosis. However, cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is available for a selected group of PC patients, which significantly increases overall survival rates up to 30%. As a consequence, there is substantial room for improvement. Tumor targeting is expected to improve the treatment efficacy of colorectal cancer (CRC) further through 1) more sensitive preoperative tumor detection, thus reducing overtreatment; 2) better intraoperative detection and surgical elimination of residual disease using tumor-specific intraoperative imaging; and 3) tumor-specific targeted therapeutics. This review focuses, in particular, on the development of tumor-targeted imaging agents. A large number of biomarkers are known to be upregulated in CRC. However, to date, no validated criteria have been described for the selection of the most promising biomarkers for tumor targeting. Such a scoring system might improve the selection of the correct biomarker for imaging purposes. In this review, we present the TArget Selection Criteria (TASC) scoring system for selection of potential biomarkers for tumor-targeted imaging. By applying TASC to biomarkers for CRC, we identified seven biomarkers (carcinoembryonic antigen, CXC chemokine receptor 4, epidermal growth factor receptor, epithelial cell adhesion molecule, matrix metalloproteinases, mucin 1, and vascular endothelial growth factor A) that seem most suitable for tumor-targeted imaging applications in colorectal cancer. Further cross-validation studies in CRC and other tumor types are necessary to establish its definitive value.

Intraoperative Assessment of Biliary Anatomy for Prevention of Bile Duct Injury: a Review of Current and Future Patient Safety Interventions

Surgical Endoscopy. Aug, 2011  |  Pubmed ID: 21487883

Bile duct injury (BDI) is a dreaded complication of cholecystectomy, often caused by misinterpretation of biliary anatomy. To prevent BDI, techniques have been developed for intraoperative assessment of bile duct anatomy. This article reviews the evidence for the different techniques and discusses their strengths and weaknesses in terms of efficacy, ease, and cost-effectiveness.

Enhancing Surgical Vision by Using Real-time Imaging of αvβ3-integrin Targeted Near-infrared Fluorescent Agent

Annals of Surgical Oncology. Nov, 2011  |  Pubmed ID: 21509632

This study was designed to improve the surgical procedure and outcome of cancer surgery by means of real-time molecular imaging feedback of tumor spread and margin delineation using targeted near-infrared fluorescent probes with specificity to tumor biomarkers. Surgical excision of cancer often is confronted with difficulties in the identification of cancer spread and the accurate delineation of tumor margins. Currently, the assessment of tumor borders is afforded by postoperative pathology or, less reliably, intraoperative frozen sectioning. Fluorescence imaging is a natural modality for intraoperative use by directly relating to the surgeon's vision and offers highly attractive characteristics, such as high-resolution, sensitivity, and portability. Via the use of targeted probes it also becomes highly tumor-specific and can lead to significant improvements in surgical procedures and outcome.

Intraoperative Imaging in Ovarian Cancer: Fact or Fiction?

Molecular Imaging. Aug, 2011  |  Pubmed ID: 21521557

Tumor-targeted fluorescence imaging for cancer diagnosis and treatment is an evolving field of research that is on the verge of clinical implementation. As each tumor has its unique biologic profile, selection of the most promising targets is essential. In this review, we focus on target finding in ovarian cancer, a disease in which fluorescence imaging may be of value in both adequate staging and in improving cytoreductive efforts, and as such may have a beneficial effect on prognosis. Thus far, tumor-targeted imaging for ovarian cancer has been applied only in animal models. For clinical implementation, the five most prominent targets were identified: folate receptor α, vascular endothelial growth factor, epidermal growth factor receptor, chemokine receptor 4, and matrix metalloproteinase. These targets were selected based on expression rates in ovarian cancer, availability of an antibody or substrate aimed at the target approved by the Food and Drug Administration, and the likelihood of translation to human use. The purpose of this review is to present requirements for intraoperative imaging and to discuss possible tumor-specific targets for ovarian cancer, prioritizing for targets with substrates ready for introduction into the clinic.

Multispectral Optoacoustic Tomography of Matrix Metalloproteinase Activity in Vulnerable Human Carotid Plaques

Molecular Imaging and Biology : MIB : the Official Publication of the Academy of Molecular Imaging. Jul, 2011  |  Pubmed ID: 21720908

AIMS: Elevated expression of cathepsins, integrins and matrix metalloproteinases (MMPs) is typically associated with atherosclerotic plaque instability. While fluorescent tagging of such molecules has been amply demonstrated, no imaging method was so far shown capable of resolving these inflammation-associated tags with high fidelity and resolution beyond microscopic depths. This study is aimed at demonstrating a new method with high potential for noninvasive clinical cardiovascular diagnostics of vulnerable plaques using high-resolution deep-tissue multispectral optoacoustic tomography (MSOT) technology. METHODS AND RESULTS: MMP-sensitive activatable fluorescent probe (MMPSenseâ„¢ 680) was applied to human carotid plaques from symptomatic patients. Atherosclerotic activity was detected by tuning MSOT wavelengths to activation-dependent absorption changes of the molecules, structurally modified in the presence of enzymes. MSOT analysis simultaneously provided morphology along with heterogeneous MMP activity with better than 200 micron resolution throughout the intact plaque tissue. The results corresponded well with epi-fluorescence images made from thin cryosections. Elevated MMP activity was further confirmed by in situ zymography, accompanied by increased macrophage influx. CONCLUSIONS: We demonstrated, for the first time to our knowledge, the ability of MSOT to provide volumetric images of activatable molecular probe distribution deep within optically diffuse tissues. High-resolution mapping of MMP activity was achieved deep in the vulnerable plaque of intact human carotid specimens. This performance directly relates to pre-clinical screening applications in animal models and to clinical decision potential as it might eventually allow for highly specific visualization and staging of plaque vulnerability thus impacting therapeutic clinical decision making.

Intraoperative Tumor-specific Fluorescence Imaging in Ovarian Cancer by Folate Receptor-α Targeting: First In-human Results

Nature Medicine. Oct, 2011  |  Pubmed ID: 21926976

The prognosis in advanced-stage ovarian cancer remains poor. Tumor-specific intraoperative fluorescence imaging may improve staging and debulking efforts in cytoreductive surgery and thereby improve prognosis. The overexpression of folate receptor-α (FR-α) in 90-95% of epithelial ovarian cancers prompted the investigation of intraoperative tumor-specific fluorescence imaging in ovarian cancer surgery using an FR-α-targeted fluorescent agent. In patients with ovarian cancer, intraoperative tumor-specific fluorescence imaging with an FR-α-targeted fluorescent agent showcased the potential applications in patients with ovarian cancer for improved intraoperative staging and more radical cytoreductive surgery.

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

Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine. Nov, 2011  |  Pubmed ID: 21990576

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 tumor-targeted 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.

The Effect of Chemotherapy on Expression of Folate Receptor-alpha in Ovarian Cancer

Cellular Oncology (Dordrecht). Feb, 2012  |  Pubmed ID: 21647742

Folate receptor alpha (FR-α) has been identified as a potential target in ovarian cancer for diagnostic and therapeutic purposes, based on its overexpression in serous epithelial ovarian carcinoma. The effect of chemotherapy on FR-α expression may be important in the applicability of FR-α directed agents in the case of residual tumor tissue. The objective of this study was to assess FR-α expression in ovarian carcinoma and to evaluate whether FR-α expression is altered by chemotherapy.

High Resolution in Vivo Bioluminescent Imaging for the Study of Bacterial Tumour Targeting

PloS One. 2012  |  Pubmed ID: 22295120

The ability to track microbes in real time in vivo is of enormous value for preclinical investigations in infectious disease or gene therapy research. Bacteria present an attractive class of vector for cancer therapy, possessing a natural ability to grow preferentially within tumours following systemic administration. Bioluminescent Imaging (BLI) represents a powerful tool for use with bacteria engineered to express reporter genes such as lux. BLI is traditionally used as a 2D modality resulting in images that are limited in their ability to anatomically locate cell populations. Use of 3D diffuse optical tomography can localize the signals but still need to be combined with an anatomical imaging modality like micro-Computed Tomography (μCT) for interpretation.In this study, the non-pathogenic commensal bacteria E.coli K-12 MG1655 and Bifidobacterium breve UCC2003, or Salmonella Typhimurium SL7207 each expressing the luxABCDE operon were intravenously (IV) administered to mice bearing subcutaneous (s.c) FLuc-expressing xenograft tumours. Bacterial lux signal was detected specifically in tumours of mice post IV-administration and bioluminescence correlated with the numbers of bacteria recovered from tissue. Through whole body imaging for both lux and FLuc, bacteria and tumour cells were co-localised. 3D BLI and μCT image analysis revealed a pattern of multiple clusters of bacteria within tumours. Investigation of spatial resolution of 3D optical imaging was supported by ex vivo histological analyses. In vivo imaging of orally-administered commensal bacteria in the gastrointestinal tract (GIT) was also achieved using 3D BLI. This study demonstrates for the first time the potential to simultaneously image multiple BLI reporter genes three dimensionally in vivo using approaches that provide unique information on spatial locations.

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