Search tips
Search criteria

Results 1-15 (15)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Towards clinically translatable NIR fluorescence molecular guidance for colonoscopy 
Biomedical Optics Express  2013;5(1):78-92.
White-light surveillance colonoscopy is the standard of care for the detection and removal of premalignant lesions to prevent colorectal cancer, and the main screening recommendation following treatment for recurrence detection. However, it lacks sufficient diagnostic yield, exhibits unacceptable adenoma miss-rates and is not capable of revealing functional and morphological information of the detected lesions. Fluorescence molecular guidance in the near-infrared (NIR) is expected to have outstanding relevance regarding early lesion detection and heterogeneity characterization within and among lesions in these interventional procedures. Thereby, superficial and sub-surface tissue biomarkers can be optimally visualized due to a minimization of tissue attenuation and autofluorescence by comparison with the visible, which simultaneously enhance tissue penetration and assure minimal background. At present, this potential is challenged by the difficulty associated with the clinical propagation of disease-specific contrast agents and the absence of a commercially available endoscope that is capable of acquiring wide-field, NIR fluorescence at video-rates. We propose two alternative flexible endoscopic fluorescence imaging methods, each based on a CE certified commercial, clinical grade endoscope, and the employment of an approved monoclonal antibody labeled with a clinically applicable NIR fluorophore. Pre-clinical validation of these two strategies that aim at bridging NIR fluorescence molecular guidance to clinical translation is demonstrated in this study.
PMCID: PMC3891347  PMID: 24466478
(170.2150) Endoscopic imaging; (170.2680) Gastrointestinal
2.  Intraoperative Imaging in Ovarian Cancer: Fact or Fiction? 
Molecular imaging  2011;10(4):248-257.
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.
PMCID: PMC3763956  PMID: 21521557
4.  High Resolution In Vivo Bioluminescent Imaging for the Study of Bacterial Tumour Targeting 
PLoS ONE  2012;7(1):e30940.
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.
PMCID: PMC3266281  PMID: 22295120
5.  Multispectral Optoacoustic Tomography of Matrix Metalloproteinase Activity in Vulnerable Human Carotid Plaques 
Molecular Imaging and Biology  2011;14(3):277-285.
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 (MMPSense™ 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.
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.
PMCID: PMC3346936  PMID: 21720908
Atherosclerosis; Optoacoustic imaging; Carotid arteries; Plaque; Contrast media; Inflammation; Medicine & Public Health; Imaging / Radiology
6.  The effect of chemotherapy on expression of folate receptor-alpha in ovarian cancer 
Cellular Oncology (Dordrecht)  2011;35(1):9-18.
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.
Materials & methods
FR-α expression was analyzed by semi-quantitative scoring of immunohistochemical staining on tissue microarrays (TMAs) from a database containing 361 ovarian cancer tissue samples, of which 210 serous and 116 non-serous carcinoma (35 missing). Serous carcinoma samples included 28 matched samples with tissue from both primary surgery and interval debulking surgery, and 12 matched samples with tissue from both primary surgery and surgery for recurrent disease.
FR-α expression was seen in 81.8% of serous ovarian cancers versus 39.9% of non-serous carcinomas (p < 0.001). In matched serous carcinoma samples, no significant change in FR-α expression in vital tumor tissue after chemotherapy was observed (p = 0.1). FR-α expression was not a prognostic marker of progression free survival (p = 0.8) or overall survival (p = 0.7).
FR-α was expressed in the majority of serous ovarian tumors, although >50% of cases showed only weak expression. Chemotherapy did not alter expression rates in remaining vital tumor tissue, indicating that folate-targeted agents may have a place in the treatment for ovarian cancer, before as well as after chemotherapy. Furthermore, FR-α status did not influence survival.
PMCID: PMC3268989  PMID: 21647742
Folate receptor-alpha; Ovarian cancer; Immunohistochemistry
7.  Intraoperative assessment of biliary anatomy for prevention of bile duct injury: a review of current and future patient safety interventions 
Surgical Endoscopy  2011;25(8):2449-2461.
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.
PubMed was searched from January 1980 through December 2009 for articles concerning bile duct visualization techniques for prevention of BDI during laparoscopic cholecystectomy.
Nine techniques were identified. The critical-view-of-safety approach, indirectly establishing biliary anatomy, is accepted by most guidelines and commentaries as the surgical technique of choice to minimize BDI risk. Intraoperative cholangiography is associated with lower BDI risk (OR 0.67, CI 0.61–0.75). However, it incurs extra costs, prolongs the operative procedure, and may be experienced as cumbersome. An established reliable alternative is laparoscopic ultrasound, but its longer learning curve limits widespread implementation. Easier to perform are cholecystocholangiography and dye cholangiography, but these yield poor-quality images. Light cholangiography, requiring retrograde insertion of an optical fiber into the common bile duct, is too unwieldy for routine use. Experimental techniques are passive infrared cholangiography, hyperspectral cholangiography, and near-infrared fluorescence cholangiography. The latter two are performed noninvasively and provide real-time images. Quantitative data in patients are necessary to further evaluate these techniques.
The critical-view-of-safety approach should be used during laparoscopic cholecystectomy. Intraoperative cholangiography or laparoscopic ultrasound is recommended to be performed routinely. Hyperspectral cholangiography and near-infrared fluorescence cholangiography are promising novel techniques to prevent BDI and thus increase patient safety.
PMCID: PMC3142332  PMID: 21487883
Cholecystectomy; CBD; Common bile duct; Complications
8.  Selecting Potential Targetable Biomarkers for Imaging Purposes in Colorectal Cancer Using TArget Selection Criteria (TASC): A Novel Target Identification Tool 
Translational Oncology  2011;4(2):71-82.
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.
PMCID: PMC3069650  PMID: 21461170
9.  Adequate debridement and drainage of the mediastinum using open thoracotomy or video-assisted thoracoscopic surgery for Boerhaave’s syndrome 
Surgical Endoscopy  2011;25(8):2492-2497.
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.
In this study, 12 consecutive patients treated with a historical nonresectional drainage approach (1985–2001) were compared with 12 consecutive patients treated prospectively after the introduction of VATS during the period 2002–2009. Baseline characteristics were equally distributed between the two groups.
In the prospective group, 2 of the 12 patients had the VATS procedure converted to an open thoracotomy, and 2 additional patients were treated by open surgery. In the prospective group, 8 patients experienced postoperative complications compared with all 12 patients in the historical control group. Four patients (17%), two in each group, underwent reoperation. Six patients, three in each group, were readmitted to the hospital. The overall in-hospital mortality was 8% (1 patient in each group), which compares favorably with other reports (7–27%) based on drainage alone.
Adequate surgical debridement with drainage of the mediastinum and pleural cavity resulted in a low mortality rate. The results for VATS in this relatively small series were comparable with those for an open thoracotomy.
PMCID: PMC3142333  PMID: 21359901
Esophageal perforation; Esophagus; Thoracic surgery; Thoracotomy; Video-assisted
11.  Multispectral Real-time Fluorescence Imaging for Intraoperative Detection of the Sentinel Lymph Node in Gynecologic Oncology 
The prognosis in virtually all solid tumors depends on the presence or absence of lymph node metastases.1-3 Surgical treatment most often combines radical excision of the tumor with a full lymphadenectomy in the drainage area of the tumor. However, removal of lymph nodes is associated with increased morbidity due to infection, wound breakdown and lymphedema.4,5 As an alternative, the sentinel lymph node procedure (SLN) was developed several decades ago to detect the first draining lymph node from the tumor.6 In case of lymphogenic dissemination, the SLN is the first lymph node that is affected (Figure 1). Hence, if the SLN does not contain metastases, downstream lymph nodes will also be free from tumor metastases and need not to be removed. The SLN procedure is part of the treatment for many tumor types, like breast cancer and melanoma, but also for cancer of the vulva and cervix.7 The current standard methodology for SLN-detection is by peritumoral injection of radiocolloid one day prior to surgery, and a colored dye intraoperatively. Disadvantages of the procedure in cervical and vulvar cancer are multiple injections in the genital area, leading to increased psychological distress for the patient, and the use of radioactive colloid.
Multispectral fluorescence imaging is an emerging imaging modality that can be applied intraoperatively without the need for injection of radiocolloid. For intraoperative fluorescence imaging, two components are needed: a fluorescent agent and a quantitative optical system for intraoperative imaging. As a fluorophore we have used indocyanine green (ICG). ICG has been used for many decades to assess cardiac function, cerebral perfusion and liver perfusion.8 It is an inert drug with a safe pharmaco-biological profile. When excited at around 750 nm, it emits light in the near-infrared spectrum around 800 nm. A custom-made multispectral fluorescence imaging camera system was used.9.
The aim of this video article is to demonstrate the detection of the SLN using intraoperative fluorescence imaging in patients with cervical and vulvar cancer. Fluorescence imaging is used in conjunction with the standard procedure, consisting of radiocolloid and a blue dye. In the future, intraoperative fluorescence imaging might replace the current method and is also easily transferable to other indications like breast cancer and melanoma.
PMCID: PMC3185642  PMID: 21048667
12.  Intraoperative Multispectral Fluorescence Imaging for the Detection of the Sentinel Lymph Node in Cervical Cancer: A Novel Concept 
Molecular Imaging and Biology  2010;13(5):1043-1049.
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.
In ten patients with early stage cervical cancer, a mixture of patent blue and ICG was injected into the cervix uteri during surgery. Real-time color and fluorescence videos and images were acquired using a custom-made multispectral fluorescence camera system.
Real-time fluorescence lymphatic mapping was observed in vivo in six patients; a total of nine SLNs were detected, of which one (11%) contained metastases. Ex vivo fluorescence imaging revealed the remaining fluorescent signal in 11 of 197 non-sentinel LNs (5%), of which one contained metastatic tumor tissue. None of the non-fluorescent LNs contained metastases.
We conclude that lymphatic mapping and detection of the SLN in cervical cancer using intraoperative NIRF imaging is technically feasible. However, the technique needs to be refined for full applicability in cervical cancer in terms of sensitivity and specificity.
Electronic supplementary material
The online version of this article (doi:10.1007/s11307-010-0425-7) contains supplementary material, which is available to authorized users.
PMCID: PMC3179588  PMID: 20835767
Cervical cancer; Near-infrared fluorescence; Sentinel lymph node; Multispectral intraoperative imaging
13.  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  2010;17(10):2656-2662.
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.
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.
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.
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.
PMCID: PMC2941712  PMID: 20865825
14.  A Critical Appraisal of Circumferential Resection Margins in Esophageal Carcinoma 
Annals of Surgical Oncology  2009;17(3):812-820.
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.
To define the optimal tumor-free CRM we included 98 consecutive patients who underwent extended esophagectomy with microscopic tumor-free resection margins (R0) between 1997 and 2006. CRMs were measured in tenths of millimeters with inked lateral margins. Outcome of patients with CRM involvement was compared with a statistically comparable control group of 21 patients with microscopic positive resection margins (R1).
A cutoff point of CRM at ≤1.0 mm and >1.0 mm appeared to be an adequate marker for survival and prognosis (both P < 0.001). The outcome in patients with CRMs ≤1.0 and >0 mm was equal to that in patients with CRM of 0 mm (P = 0.43). CRM involvement was an independent prognostic factor for both recurrent disease (P = 0.001) and survival (P < 0.001). Survival of patients with positive CRMs (≤1 mm) did not significantly differ from patients with an R1 resection (P = 0.12).
Involvement of the circumferential resection margins is an independent prognostic factor for recurrent disease and survival in esophageal cancer. The optimal limit for a positive CRM is ≤1 mm and for a free CRM is >1.0 mm. Patients with unfavorable CRM should be approached as patients with R1 resection with corresponding outcome.
PMCID: PMC2820690  PMID: 19924487
15.  Obtaining Adequate Surgical Margins in Breast-Conserving Therapy for Patients with Early-Stage Breast Cancer: Current Modalities and Future Directions 
Annals of Surgical Oncology  2009;16(10):2717-2730.
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.
PMCID: PMC2749177  PMID: 19609829

Results 1-15 (15)