High-intensity focused ultrasound: advances in technology and experimental trials support enhanced utility of focused ultrasound surgery in oncology

Abstract

High-intensity focused ultrasound (HIFU) is a rapidly maturing technology with diverse clinical applications. In the field of oncology, the use of HIFU to non-invasively cause tissue necrosis in a defined target, a technique known as focused ultrasound surgery (FUS), has considerable potential for tumour ablation. In this article, we outline the development and underlying principles of HIFU, overview the limitations and commercially available equipment for FUS, then summarise some of the recent technological advances and experimental clinical trials that we predict will have a positive impact on extending the role of FUS in cancer therapy.

Figure 1.

Diagram illustrating focusing principles of high-intensity focused ultrasound in single (a) and array (b) transducers. Reproduced with permission from Pioneer Bioscience Publishing Company, from Khokhlova and Hwang [16].

Figure 2.

The spherical surface of a patented array transducer with randomly distributed elements that allows multiple simultaneous foci and minimises off-target energy delivery. Reproduced with permission from IOP Publishing Ltd, from Hand et al [26].

Figure 3.

Examples of high-intensity focused ultrasound devices currently in Western clinical use or research. (a) Ablatherm® (EDAP TMS, Lyon, France), (b) ExAblate® OR (InSightec, Haifa, Israel), (c) Sonablate® 500 (SonaCare Medical, Charlotte, NC, previously Focus Surgery Inc., Indianapolis, IN), (d) Sonalleve MR-HIFU (Philips Healthcare, Guildford, UK), (e) ExAblate Neuro (InSightec). Figures are reproduced with permission from the manufacturers.