A team of scientists from NPL and the University Hospitals Bristol NHS Foundation Trust have successfully completed an initial trial of a new, potentially more reliable, technique for screening breast cancer using ultrasound, and are now looking to develop the technique into a clinical device.

46,000 women are diagnosed with breast cancer in the UK each year, using state-of-the-art breast screening methods based on X-ray mammography, but only about 30% of suspicious lesions turn out to be malignant.

Each lesion must be confirmed by invasive biopsies, estimated to cost the NHS £35 million per year. Ionising radiation from X-rays also has the potential to cause cancer, which limits their use to single screenings of at risk groups, such as women over 50 years old.

There is, therefore, a compelling need to develop improved, ideally non-ionising, methods of detecting breast lesions and solid masses. Improved diagnosis would reduce unnecessary biopsies and the patient trauma associated with being wrongly diagnosed.

Ultrasound ticks many of the boxes: it is safe, low cost, and already extensively used in trusted applications such as foetal scanning. However, the quality of the images is not yet good enough for reliable diagnoses.

Part of the problem lies with the current detectors used. Different biological tissues have different sound speeds, and this affects the time taken for sound waves to arrive at the detector. This can distort the arriving waves, resulting in imaging errors such as suggesting abnormal inclusions where there may be none.

The new method trialled in this research works by detecting the intensity of ultrasonic waves. Intensity is converted to heat that is then sensed by a thin membrane of pyroelectric film, which generates a voltage output dependant on the temperature rise. Imaging detectors based on this new principle should be much less susceptible to the effects caused by the uneven sound speed in tissues.

An initial feasibility project has proved the concept by testing single detectors using purpose-built artefacts and the results confirmed that the new detectors generated more reliable maps of the internal structure of the artefacts than existing techniques.

Having received positive results and proven the potential of the project, NPL is now seeking funding to develop the work further.

The team hope to produce a demonstrator using a full array of 20 sensors, which should allow more rapid scanning and move the idea towards a system which might eventually be used clinically. Following successful completion of the demonstrator, NPL and the project partners will look to work with a manufacturer to commercialise the technology.

Dr Bajram Zeqiri, who leads the project at NPL, said:

"Our initial results are very promising. Whilst it's early days, we're very excited about its potential and, with the right funding, support and industry partners, we may well have something here which could have a huge and positive impact on cancer diagnosis and the lives of many thousands of women."

The project was funded by the research arm of the NHS, the National Institute of Health Research, under the Invention for Innovation funding stream, and co-funded by the NPL Strategic Research Programme.

Source: NPL