'Virtual biopsy' device can non-invasively detect skin tumours

Scientists have developed a 'virtual biopsy' device that can quickly and non-invasively determine whether a skin tumour is cancerous and needs to be removed surgically.

Using sound vibrations and pulses of near-infrared light, the device can determine a skin lesion's depth and potential malignancy without using a scalpel, according to the researchers from a Rutgers University in the US.

The ability to analyse a skin tumour non-invasively could make biopsies much less risky and distressing to patients.

Currently, physicians who perform surgical biopsies often do not know the extent of a lesion -- and whether it will be necessary to refer the patient to a specialist for extensive tissue removal or plastic surgery -- until surgery has already begun.

The first-of-its-kind experimental procedure, called vibrational optical coherence tomography (VOCT), creates a 3D map of the legion's width and depth under the skin with a tiny laser diode.

It also uses soundwaves to test the lesion's density and stiffness since cancer cells are stiffer than healthy cells. An inch-long speaker applies audible soundwaves against the skin to measure the skin's vibrations and determine whether the lesion is malignant.

"This procedure can be completed in 15 minutes with no discomfort to the patient, who feels no sensation from the light or the nearly inaudible sound," said Frederick Silver, a professor at Rutgers University.

"It's a significant improvement over surgical biopsies, which are invasive, expensive and time consuming," said Silver.

The study found that a prototype device is able to accurately distinguish between healthy skin and different types of skin lesions and carcinomas.

The researchers tested the device over six months on four skin excisions and on eight volunteers without skin lesions.

Further studies are needed to fine-tune the device's ability to identify a lesion's borders and areas of greatest density and stiffness, researchers said, which would allow physicians to remove tumours with minimally invasive surgery.