Interstitial thermal ablation with a fast rotating dual-mode transducer

Area of Science:

• Medical physics
• Biomedical engineering
• Minimally invasive therapies

Background:

• Interstitial ultrasound applicators offer a minimally invasive approach for treating unresectable or inaccessible targets.
• Miniaturized applicators and real-time monitoring present challenges in ultrasound-guided therapies.

Purpose of the Study:

• To develop and evaluate an original treatment strategy combining ultrasound imaging and therapy using a rotating dual-mode transducer.
• To assess the feasibility and sustainability of real-time imaging and deep thermal ablation with this novel system.

Main Methods:

• A dual-mode transducer was designed for simultaneous imaging and therapy, rotating at 8 revolutions per second.
• Numerical simulations were conducted to analyze tissue heating and transducer temperature.
• A prototype system was tested in vitro on porcine liver samples, utilizing apparent strain imaging.

Main Results:

• The rotating dual-mode transducer enabled real-time B-mode imaging interleaved with high-intensity ultrasound therapy.
• Narrower therapy apertures produced deeper lesions, with lesions up to 8 mm achieved under specific parameters.
• Apparent strain imaging enhanced visualization of treated versus spared tissue compared to B-mode imaging.

Conclusions:

• Real-time imaging and deep thermal ablation are feasible and sustainable using a rotating dual-mode transducer.
• Controlling transducer output is crucial for maintaining safety and efficacy.
• This technology presents a promising advancement for minimally invasive interstitial treatments.