Laser device detects breast cancer that X-rays can miss

A new optical screening device could help to detect aggressive breast cancers in younger women which conventional screening sometimes misses, while also being much less umcomfortable for the patient. Developed primarily at Florida International University, the system, which illuminates tissue with a near-infrared diode laser in a hand-held device and uses commercially-available charge-coupled devices (CCDs) as detectors, does not carry the risks of using ionising radiation, unlike X-ray mammography.

Mammography is regarded as the gold-standard for breast cancer detection, but it has a 20 per cent false-negative rate (that is, cancer is present but undetected), this figure rises when it is used on the more dense breast tissue of younger women, in whom breast cancer tends to be more aggressive.

The Florida team developed scanning heads that adapt to the shape of the patient’s breast and use optical fibres to split the laser and direct it at different angles into various points on the breast; the transmitted light is detected by 165 detector fibres linked to the CCD. The device detects the optical absorption of the infrared radiation, which is altered by the presence of haemoglobin; abnormal blood-flow in the breast tissue can indicate the presence of a tumour, which distorts the normal circulatory structure to supply itself with oxygen. Unlike a mammogram, the device allows scanning of the chest wall region.