Image: The EchoPulse device treats benign tumors non-invasively (Photo courtesy of Theraclion).
A combination of high intensity focused ultrasound (HIFU) and echotherapy can treat benign tumors such as breast fibroadenomas and thyroid nodules.
The Theraclion (Paris, France) EchoPulse device works by delivery of concentrated HIFU directly to the tumor via an image-guided targeting system, resulting in precise tissue necrosis. The heart of the system is the HIFU piezoelectric transducer, with a frequency of 3 MHz, a maximal acoustic power of 125 W, and automatic depth compensation feature. The second ultrasonic system component is a transducer that operates on a frequency range of 7.5-12 MHz, which provides real-time monitoring of the target area.
Both ultrasound components are housed in the visualization and treatment unit (VTU), which also includes an articulated arm for easy positioning on the treatment area, and a motorized head able to perform not only sagittal and transverse slices, but also micro-movements with millimetric precision thanks to finely tuned electromagnetic friction brakes. The system also includes a patient movement detector and a touch-screen user interface that provides step-by-step procedural control.
Also included is a disposable EPack for the cooling system that is replaced before each treatment. The cooling system allows the ultrasound waves to be transmitted without loss or distortion, while at the same time protecting the patient’s skin from the heat of the HIFU waves. It includes a cooling pack, two pumps, a disposable set of tubing, and a pouch containing 500 ml of fluid. The pump circulates the fluid in a closed circuit between the pouch and the VTU, with a temperature sensor to ensure that the fluid is properly cooled; internal pressure is then adjusted accordingly.
“Advantages of the system include non-invasive, scarless treatment under conscious sedation; fast, efficient, and harmless procedural protocols for practitioners; and lower costs of hospitalization for medical centers,” said the company in a statement. “The idea for this technology was developed by EDAP in 1993. Theraclion is partnering with University of Virginia for proceeding with clinical studies.”
HIFU technology is based on nonlinear acoustic mathematical optimization methods to analyze and simulate the propagation of sound in material. The information is then used to enhance the shape of an acoustic lens so that that ultrsound pressure is focused precisely on the location of the tissue to be ablated, while the surrounding tissue retains as little damage as possible.