Interview of Laurent Sandrin, Chairman and Chief Technology Officer at Echosens

Could you briefly outline how VCTE™ works?

 

FibroScan® is based on a unique, patented technology: VCTE™. VCTE™ stands for ‘Vibration Controlled Transient Elastography’.

VCTE™ involves generating a shear wave. The shear wave is a low-frequency elastic wave that propagates through tissues. This wave has an astonishing property: its speed varies according to the stiffness. The FibroScan® probe is placed on the surface of the skin, where it vibrates and generates a shear wave that propagates in the liver. We use ultrasound to measure the speed of the wave, because ultrasound is not sensitive to changes in stiffness.

 

What are the advantages of VCTE™?

 

VCTE™ has several advantages.

The first is the perfect control of the shear wave. The shear wave is the source of the measurement, since its speed is what allows us to determine the stiffness.

With FibroScan®, we have perfect control of the amplitude and frequency of the shear wave. Its frequency is 50 Hz, and it is important to maintain this frequency to be able to compare the measurements from any patient, wherever in the world the measurements were taken.

The second advantage of VCTE™ is that the procedure used for examinations carried out with FibroScan® is highly standardised: always the same number of measurements, always the same acquisition method, and the same shear wave characteristics. It is very important that the result should be repeatable and robust.

 

Can you briefly tell us about the clinical studies carried out on VCTE™?

 

The first application of liver stiffness is the correlation with the degree of liver fibrosis determined by biopsy. Many studies have shown that there is excellent correlation in the context of cirrhosis, and very good correlation for mutilating fibrosis and significant fibrosis.

Other studies have shown that stiffness itself is also of interest in its own right, because it is also sensitive to other liver conditions. In particular, I mean liver congestion and inflammation.

More recently, studies have shown that elasticity provides a way to predict patient survival, and I think that this might be the most important point.

Finally, I would also like to extend the scope to new parameters that can be measured with VCTE™.  In particular, I mean the CAP™, which is an ultrasonic attenuation controlled by the stiffness measurement, which provides a method for quantifying steatosis in the liver.