High-tech bra may help spot cancer

A fibre-optic brassiere that avoids using potentially harmful X-rays could soon be used to help detect breast cancer.

Scientists at University College London are due "within months" to complete a movable bedside imager that uses near-infrared (NIR) light to see inside the soft tissues of the body.

Instead of conventional X-ray mammography, the imager uses 32 fibres attached around the breast to read and feed back any changes taking place.

"NIR imaging should provide an excellent method of pre-screening for breast cancer because it is particularly good at picking up the changes associated with the development of small tumours," said Professor David Delpy, who is heading the development team within the medical physics and bio-engineering department at UCL. The number of blood vessels increases significantly around a growing tumour and NIR can track haemoglobin, the red pigment in blood.

"X-rays are less effective at spotting small tumours. They detect the small calcifications found in a tumour, but small ones often don't contain many of these," said Prof Delpy, who introduced the method at yesterday's conference, Medical Engineering - Improving the Quality of Life, at the Royal Society of Medicine in London.

Working with NIR light is difficult because breast tissue absorbs so much of the light energy that the detecting fibres are almost counting single photons - the smallest possible amounts of light.

But NIR light is completely harmless and can be used repeatedly or continuously, even on pregnant women. It also avoids the need for compression of the breast, which many women find painful and off-putting.

It may also become a useful tool for brain scanning, because it can identify damaged areas caused by a blow to the head. The UCL team is already using a larger, stationary version of the NIR system to monitor the brains of premature babies to identify early symptoms of damage.

"At the moment it looks a little like an Indian head-dress, with the fibres being held in place around the head by an elastic strip and double-sided tape," said Prof Delpy.

"At 26/27 weeks gestation babies have a head measurement of 6 or 7 cm ... and the system allows us to monitor the brain in a non invasive and totally safe manner. You can leave it on continuously. You are probably getting as much infra-red light on your head now as you would get from the system."

A number of major commercial manufacturers have shown an interest in the movable prototype, which is due for completion in six to seven months and whose development is being partly funded by the Wellcome Trust.

According to Professor Delpy, the overall cost of the NIR scans should be less than for current X-rays. Most of the technology for the new system was already in place, he said, and should be manufactured quite easily.

"It's not a competitor for X-ray mammography, it's just meant to complement it. If it works I would see someone having an X-ray mammograph and an optical image at the same time," he added.

"There's no problem of accumulation radiation growth so you could come back every six months and could then look for differences in the scans."