Radio and sound waves to image cancer treatment

This proposal aims to take a novel imaging technique that has been developed in the Electrical Engineering and Biomedical Engineering laboratories at the University of Oxford and turn it into a system that can be used to image the body. The novel imaging technique is referred to as electromagnetic acoustics (EMA) and it works by sending ultrasound waves and radio waves into the body. The interaction of the ultrasound and radio waves depends strongly on the properties of the tissue and by detecting the scattered radio waves the tissue properties can be assessed with a resolution of about 1 mm. The EMA information will be generated by simply mounting a metal coil around a standard diagnostic ultrasound probe and through appropriate processing of the radio waves from the coil an EMA image can be created that can be mapped onto the standard ultrasound image. The EMA image will provide magnetic resonance (MR)-like information but at much lower cost than conventional MR imaging. The ultrasound and RF waves have minimal inherent risks and so there will be no concerns with radiation dose as occurs with x-ray imaging. In this proposal we will look at two particular applications one is monitoring the treatment of cancer tumours and the second is to detect breast cancer.

The cancer application is aimed at minimally invasive surgery of tumours which is very attractive because it is easier on the patient than open surgery. The therapy we will consider is when either heat or cold are used to destroy cancerous tissue in place which means the tissue doesn't need to be physically removed as the body natural absorbs it. One disadvantage of this approach is that the surgeon can often not directly see what tissue is being destroyed and what is being spared. Standard imaging techniques, such as ultrasound, MR and x-ray, are not very good up picking up the changes. EMA should be very sensitive to the changes as both the stiffness and dielectric properties change when the tissue is destroyed. We will work with doctors at the Cancer Centre at the Churchill Hospital in Oxford to determine how well EMA works on detecting tissue that has been destroyed by their clinical devices. If this is successful it will allow for them to treat far more cancerous tumours with minimally invasive surgery then they can do at present.

In the breast cancer diagnosis the aim is to have EMA be used alongside other ultrasound based methods for determining whether breast tissue is cancerous. At present ultrasound methods are good at detecting suspicious regions of tissue in the breast but to confirm that the tissue is cancerous a biopsy needs to be done. Unfortunately ultrasound is not so good at distinguishing between benign and cancerous tissue and about 80% of biopsies shown no sign of cancer. We will use EMA to image patients who will undergo biopsies. We expect that the EMA signal will be stronger for cancerous tissue and if confirmed by this study then EMA could be used reduce the number of unnecessary biopsies.

If EMA is successful in these two applications then we will expand it to other areas. For example, we would explore its capability to detect other cancer tumours, e.g., in the prostate, pancreas, liver and kidney. It could also detect other diseases that result in changes in stiffness or dielectric properties, such as hardened arteries. We would also explore its ability to track changes in tissue associated with other treatments for cancer, such as, radiation or chemotherapy, as we anticipate that dielectric and stiffness properties will change during treatment.

The dominant impact of this research will be on the use of EMA to manage cancer by 1/ removing an imaging barrier for minimally invasive cancer therapeutics and 2/ providing new diagnostic information about tissue in order to improve detection of breast cancer without the need for biopsy. The key beneficiaries are going to be patients, both in the UK and elsewhere in the world, who need treatment or diagnosis. In order to bring EMA technology from the laboratory bench to the bed-side most quickly, it will be necessary to incorporate EMA into current therapy and diagnostic platforms. The principal vehicle for this will be, OxEMA, a company that has been formed in conjunction with Isis Innovation Ltd which is a University owned organization with a goal of commercializing technology developed at the University. Within our team we already have existing interactions with therapy companies (e.g., HAIFU and Philips) and imaging companies, (e.g., Philips, Ultrasonix and Zonare) and we envision OxEMA being able to engage companies in order to bring British-developed EMA technology into clinical settings all over the world within a five year time frame.

Beyond the direct applications described in this proposal we envision that EMA will have a broader impact in a five-ten year time frame in both therapeutics and diagnostics. In therapeutics removing the barrier of imaging ablation will allow for more minimally invasive therapies to be employed for a wider range of diseases, both within the cancer arena and in treatment of other diseases. For example, the use of ultrasound for therapy is hindered by the need (in most cases) for real-time MR guidance which increases the cost dramatically. A therapy system using EMA imaging for guidance would dramatically reduce the cost making the use of this non-invasive procedure available to more patients. For diagnostics EMA will almost certainly have application outside of breast tumour classification as many other tumours have changes in stiffness and dielectric properties (e.g., liver and prostate). Further, other pathologies in the body, such as, arterial wall stiffening and ulcers, would also be potential areas for impact of EMA.