Radiofrequency ablation with four electrodes as a building block for matrix radiofrequency ablation: Ex vivo liver experiments and finite element method modelling. Influence of electric and activation mode on coagulation size and geometry.

Purpose: Radiofrequency ablation (RFA) is increasingly being used to treat unresectable liver tumors. Complete ablation of the tumor and a safety margin is necessary to prevent local recurrence. With current electrodes, size and shape of the ablation zone are highly variable leading to unsatisfactory local recurrence rates, especially for tumors >3 cm.

Prognostic features of breast cancer differ between women in the Democratic Republic of Congo and Belgium.

Objectives: Compared to European women, breast cancers in African women present at a younger age, with a higher tumor grade and are more often estrogen receptor (ER)/progesterone receptor (PR) negative. We here investigate the histopathological and immunohistochemical characteristics (ER, PR and human epidermal growth receptor 2 (HER2)) and the proportion of triple negative (Tneg) invasive breast cancers from an unselected series of patients diagnosed in Kinshasa, and compare them to a population of Caucasian women with a palpable breast cancer.

Materials And Methods: From 2010 till 2013, during the first breast cancer awareness campaign, organized in Kinshasa, 87 patients were diagnosed with invasive breast cancer.

Bipolar radiofrequency ablation with 2 × 2 electrodes as a building block for matrix radiofrequency ablation: Ex vivo liver experiments and finite element method modelling.

Purpose: Size and geometry of the ablation zone obtained by currently available radiofrequency (RF) electrodes is highly variable. Reliability might be improved by matrix radiofrequency ablation (MRFA), in which the whole tumour volume is contained within a cage of x × y parallel electrodes. The aim of this study was to optimise the smallest building block for matrix radiofrequency ablation: a recently developed bipolar 2 × 2 electrode system.

From the set-up of a screening program of breast cancer patients to the identification of the first BRCA mutation in the DR Congo.

Background: Breast cancer incidence in African population is low compared to western countries but the mortality rate is higher and the disease presents at a younger age and at a more advanced stage. The World Health Organisation and the Breast Health Global Initiative concluded that in low and middle income countries early breast cancer detection can be achieved by informing women on symptoms of breast cancer, on the practice of breast self-examination and clinical breast examination by trained health care workers. Based on these recommendations, we set up a breast cancer awareness campaign in Kinshasa, Democratic Republic of Congo (DRC).

Separate calculation of DW-MRI in assessing therapeutic effect in liver tumors in rats.

Aim: To explore whether the antitumor effect of a vascular disrupting agent (VDA) would be enhanced by combining with an antiangiogenic agent, and whether such synergistic effects can be effectively evaluated with separate calculation of diffusion weighted magnetic resonance imaging (DW-MRI).

Methods: Thirty-seven rats with implanted liver tumors were randomized into the following three groups: (1) ZD6126, a kind of VDA; (2) ZDTHA, ZD6126 in combination with an antiangiogenic, thalidomide; and (3) control. Morphological DW-MRI were performed and quantified before, 4 h and 2 d after treatment.

Bipolar radiofrequency ablation with four electrodes: ex vivo liver experiments and finite element method analysis. Influence of inter-electrode distance on coagulation size and geometry.

Purpose: The aim of this study was to develop an electrode system with simple needle electrodes which would allow a reliable and predictable ablation zone with radiofrequency ablation (RFA).

Materials And Methods: In the first step, four parallel electrodes (active length 3 cm, diameter 1.8 mm) were inserted in ex vivo bovine liver.

Enhanced antitumor efficacy of a vascular disrupting agent combined with an antiangiogenic in a rat liver tumor model evaluated by multiparametric MRI.

A key problem in solid tumor therapy is tumor regrowth from a residual viable rim after treatment with a vascular disrupting agent (VDA). As a potential solution, we studied a combined treatment of a VDA and antiangiogenic. This study was approved by the institutional ethical committee for the use and care of laboratory animals.

Comparison of two vascular-disrupting agents at a clinically relevant dose in rodent liver tumors with multiparametric magnetic resonance imaging biomarkers.

We sought to compare the therapeutic efficacy between two vascular-disrupting agents, combretastatin A4 phosphate (CA4P) and ZD6126, at a clinically relevant dose on tumor models with magnetic resonance imaging (MRI). Thirty rats with liver rhabdomyosarcoma were randomized into CA4P (10 mg/kg), ZD6126 (10 mg/kg), and control group (n=10 for each group). Multiparametric MRI biomarkers including tumor volume, enhancement ratio, necrosis ratio, apparent diffusion coefficient (ADC), and K (volume transfer constant) derived from T2-weighted, T1-weighted, contrast-enhanced T1-weighted, and diffusion-weighted imaging, and dynamic contrast-enhanced MRI were compared at pretreatment, 1 h, 6 h, 24 h, 48 h, and 120 h posttreatment; they were validated using ex-vivo techniques.

A dual-targeting anticancer approach: soil and seed principle.

Purpose: To test the hypothesis that targeting the microenvironment (soil) may effectively kill cancer cells (seeds) through a small-molecular weight sequential dual-targeting theragnostic strategy, or dual-targeting approach.

Materials And Methods: With approval from the institutional animal care and use committee, 24 rats were implanted with 48 liver rhabdomyosarcomas (R1). First, the vascular-disrupting agent combretastatin A4 phosphate (CA4P) was injected at a dose of 10 mg/kg to cause tumor necrosis, which became a secondary target.

Comparison between nonspecific and necrosis-avid gadolinium contrast agents in vascular disrupting agent-induced necrosis of rodent tumors at 3.0T.

Objective: : To compare a commercial contrast agent (CA) Dotarem and a necrosis-avid CA (NACA) for their ability to evaluate the therapeutic necrosis with a vascular disrupting agent (VDA) on magnetic resonance imaging in rodent liver tumors to determine which could better correlate with the histopathologic outcome.

Methods: : After the VDA treatment, 16 rats with 32 liver rhabdomyosarcomas were randomized into Dotarem and NACA groups (n = 8 per group) for both interindividual and intraindividual comparisons. T2-weighted imaging, T1-weighted imaging (T1WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and diffusion-weighted imaging were performed at baseline, after VDA treatment and CA injections.

Multiparametric MRI biomarkers for measuring vascular disrupting effect on cancer.

Solid malignancies have to develop their own blood supply for their aggressive growth and metastasis; a process known as tumor angiogenesis. Angiogenesis is largely involved in tumor survival, progression and spread, which are known to be significantly attributed to treatment failures. Over the past decades, efforts have been made to understand the difference between normal and tumor vessels.

Does digital mammography in a decentralized breast cancer screening program lead to screening performance parameters comparable with film-screen mammography?

Objective: To evaluate if the screening performance parameters of digital mammography (DM) in a decentralized screening organization were comparable with film-screen mammography (FSM).

Methods: A nationwide screening program was launched in 2001, and since 2005 screening with DM has been allowed. Firstly, the parameters of the three regional screening units (RSUs) that first switched to DM (11,355 women) were compared with the FSM period of the same three RSUs (23,325 women).

Morphological, functional and metabolic imaging biomarkers: assessment of vascular-disrupting effect on rodent liver tumours.

Objectives: To evaluate effects of a vascular-disrupting agent on rodent tumour models.

Methods: Twenty rats with liver rhabdomyosarcomas received ZD6126 intravenously at 20 mg/kg, and 10 vehicle-treated rats were used as controls. Multiple sequences, including diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) with the microvascular permeability constant (K), were acquired at baseline, 1 h, 24 h and 48 h post-treatment by using 1.

Quantitative diffusion tensor imaging in amyotrophic lateral sclerosis: revisited.

Voxel-based analyses (VBA) are increasingly being used to detect white matter abnormalities with diffusion tensor imaging (DTI) in different types of pathologies. However, the validity, specificity, and sensitivity of statistical inferences of group differences to a large extent depend on the quality of the spatial normalization of the DTI images. Using high-dimensional nonrigid coregistration techniques that are able to align both the spatial and orientational diffusion information and incorporate appropriate templates that contain this complete DT information may improve this quality.

Evaluation of clinical image processing algorithms used in digital mammography.

Screening is the only proven approach to reduce the mortality of breast cancer, but significant numbers of breast cancers remain undetected even when all quality assurance guidelines are implemented. With the increasing adoption of digital mammography systems, image processing may be a key factor in the imaging chain. Although to our knowledge statistically significant effects of manufacturer-recommended image processings have not been previously demonstrated, the subjective experience of our radiologists, that the apparent image quality can vary considerably between different algorithms, motivated this study.

Tumor models and specific contrast agents for small animal imaging in oncology.

Despite the widespread use of various imaging modalities in clinical and experimental oncology without or with combined application of commercially available nonspecific contrast agents (CAs), development of tissue- or organ- or disease-specific CAs has been a continuing effort for pursuing ever-improved sensitivity, specificity, and applicability. This is particularly true with magnetic resonance imaging (MRI) due to its intrinsic superb spatial/temporal/contrast resolutions and adequate detectability for tiny amount of substances. In this context, research using small animal tumor models has played an indispensible role in preclinical exploration of tissue specific CAs.

Diffusion-weighted MRI of hepatic tumor in rats: comparison between in vivo and postmortem imaging acquisitions.

Purpose: To determine the feasibility of in vivo diffusion-weighted imaging (DWI) to distinguish between normal liver, viable tumor and necrosis compared to postmortem DWI in a rat model with vascular-targeting treatment.

Materials And Methods: Fifteen rats with liver implantation of 30 rhabdomyosarcomas were treated with combretastatin A-4-phosphate (CA4P) at 10 mg/kg. Two days after treatment, T2-weighted imaging, precontrast T1-weighted imaging, postcontrast T1-weighted imaging, and DWI were performed in vivo and postmortem with a 1.

Radiofrequency ablation versus resection for resectable colorectal liver metastases: time for a randomized trial? An update.

Background: A recent proposal of a randomized trial comparing resection and radiofrequency ablation (RFA) in a selected subgroup of patients with small resectable colorectal liver metastases (CRLM) has initiated a debate on this issue. Meanwhile, new data have been published. The aim of the study was to update and critically review the oncological evidence in favor of and against the use of RFA for resectable CRLM in general and in favor of and against conducting a randomized trial in a selected subgroup of patients.

A modified rabbit model of reperfused myocardial infarction for cardiac MR imaging research.

We sought to obtain a rabbit myocardial infarction (MI) model for research with cardiac magnetic resonance imaging (cMRI) by overcoming a few technical difficulties. A novel endotracheal method was developed for intubation and ventilation. Fourteen rabbits were divided into group-1 (n = 8) with open-chest occlusion of left circumflex coronary artery and closed-chest reperfusion, and group-2 (n = 6) of non-ischemic control; and received ECG-triggered cMRI with delayed contrast enhancement (DE-cMRI) at a 1.

Treatment of rodent liver tumor with combretastatin a4 phosphate: noninvasive therapeutic evaluation using multiparametric magnetic resonance imaging in correlation with microangiography and histology.

Objectives: To document tumoricidal events after intravenous administration of a vascular targeting agent combretastatin A-4-phosphate (CA4P) in rodent liver tumors by using multiparametric magnetic resonance imaging (MRI) in correlation with microangiography and histopathology.

Materials And Methods: Thirty rhabdomyosarcomas of 8 to 14 mm in diameter were obtained 16 days after implantation in liver lobes of 15 rats. Using a 1.

An improved method for simulating microcalcifications in digital mammograms.

The assessment of the performance of a digital mammography system requires an observer study with a relatively large number of cases with known truth which is often difficult to assemble. Several investigators have developed methods for generating hybrid abnormal images containing simulated microcalcifications. This article addresses some of the limitations of earlier methods.

Computed tomographic colonography: automated tool for polyp measurement delivering on patient risk stratification.

Objective: We evaluated an automated polyp size measurement tool in computed tomographic colonography for its accuracy and value for patient risk stratification.

Methods: A simulation program generated a raw data phantom with sessile and pedunculated polyps of known sizes using 120 to 140 kV and 50, 40, 20, 15, and 10 mAs. All polyps were measured by clicking on the polyp surface.

Murine liver implantation of radiation-induced fibrosarcoma: characterization with MR imaging, microangiography and histopathology.

We sought to establish and characterize a mouse liver tumor model as a platform for preclinical assessment of new diagnostics and therapeutics. Radiation-induced fibrosarcoma (RIF-1) was intrahepatically implanted in 27 C3H/Km mice. Serial in vivo magnetic resonance imaging (MRI) with a clinical 1.

Clinical image quality criteria for full field digital mammography: a first practical application.

In order to quantify the clinical quality of full-field digital mammography, a set of image quality parameters is developed. The set consisted of 12 image quality criteria and 8 physical characteristics of the image. The first set interrogates the visibility of anatomical structures and typical characteristics of a digital image, such as noise and saturation of dark and white areas.