Therapeutic Ultrasound Group

The main goal of our research is to develop high-intensity focused ultrasound surgery (HIFU) to the point at which it becomes a useful clinical tool for the treatment of appropriate soft-tissue tumours. To this end, we are working on the optimisation of the delivery of the ultrasound energy, on increasing understanding of the mechanisms by which tissue is destroyed, and is developing new methods of targeting tumours. The main mechanisms for target destruction are heating and acoustic cavitation (bubble formation and activity). We are developing a clinical prototype device with improved treatment delivery and monitoring capabilities.

We are also working with the Magnetic Resonance (MR) Group to develop MR imaging techniques for treatment guidance and monitoring. Focused ultrasound surgery techniques rely on raising the temperature of the target tissue volume to levels in excess of 56ºC and maintaining them for 1–2 s. This leads to instantaneous cell death and is known as thermal ablation. Methods for optimising the rate of tissue ablation are being sought. Blood flow within the target organ may be expected to produce localised cooling. We are studying this important topic both experimentally and theoretically.

Our work with isolated blood vessels is designed not only to inform the safe use of diagnostic ultrasound and contrast agents, but also to help understand the mechanisms by which ultrasound can enhance the delivery of chemotherapeutic agents.

The research in our group addresses many aspects of existing and novel applications of ultrasound in cancer therapy. Ultrasound is extremely versatile, allowing, as it does, imaging to provide diagnosis and treatment monitoring, enhancement of radio- and chemo-therapy effects by thermal and/or mechanical means, stimulation of immune responses, and tissue ablation using high temperatures (HIFU) or bubble driven mechanical disruption (histotripsy).

Our interests lie in harnessing this potential for therapeutic benefit, designing appropriate systems, doing pre-clinical research to understand these phenomena and to optimise potential therapies, and then translating them into the clinic.

The basic principle of HIFU is that a high power ultrasound beam is brought to a tight focus at a distance from its source and is used to heat tissue rapidly to temperatures which result in instantaneous cell death. Only cells within the focus are killed - overlying and surrounding tissue is unharmed. If the source is positioned outside the body, this provides a non-invasive treatment for tumours lying deep below the skin. This treatment is rapidly gaining widespread clinical acceptance, and we are at the forefront of its development.