Université d'Auvergne Clermont1 | CNRS

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Axis 3: Embolization in parenchymal disease

Context

This axis federates activities of fundamental and applied research around interventional targeted therapies (transarterial chemoembolization, embolization) for liver cancer.

These approaches allow a minimally invasive approach to complex pathologies or weakened patients. We are working on the development of endovascular techniques and new assessment tools (3D contrast enhanced ultrasound) to quantify the tumoral perfusion, which is critical in validating their therapeutic impact.  

Objectives 

Clinical objective: standardization of transarterial chemoembolization in pigs

Transarterial chemoembolization involves an intra-arterial injection of drug (cisplastin-lipiodol) directly to the liver tumor via a catheter. The lack of standardization in terms of selectivity, level (partial or total), duration and nature of embolization material, the dose of chemotherapy, place of administration (selective or not selective), makes the comparison of results between clinical centers difficult. In collaboration with the CHU Estaing and the Clinical Center of Investigation, we study the cisplatin pharmacokinetics and the effects of the level of embolization in pigs to standardize the technique.

 
 Embolization guidance with Digital Subtraction Angiography.  Bland vs. loaded particles for chemoembolization.

Technical objective: evaluation of tumoral response by 3D Contrast Enhanced Ultrasound

Contrast enhanced ultrasound is a new ultrasound modality based on the intravenous injection of contrast agents. As contrast agents are strictly intravascular, they behave as a tracer to assess tissue vascularization in both temporal and spatial domain. A real time sequence of micro as macro vascularisation can be obtained , thus enabling the evaluation of the efficiency of the thransarterial chemoembolization.  In routine, the assessment of vascular kinetics from 2D contrast enhanced ultrasound is often based on a quantitative analysis of pixel intensity, related to contrast agent concentration. Intensity variations, as a function of time, may be related to blood flow, to vascular volume, and to the relative proportion of viable tumor. Reliability depends on the homogeneity of the signal to noise ratio, and on the uniformity of the acoustic field in the selected region of interest. In parallel with this 2D technique, 3D information available with recent ultrasound scanners, allow three-dimensional analysis of vascularization, thus improving the localization and assessment of out of the plane. In this context, we plan to develop 3D contrast enhanced ultrasound technique and to build a generic tool for quantification of perfusion, with quantitative parameters for the monitoring of chemoembolization.

Publications