A team headed up at Rutgers University has developed a device that performs virtual biopsies of skin lesions, by combining optical coherence tomography images with stiffness measurements performed simultaneously using vibrational analysis. The technique, termed vibrational optical coherence tomography (VOCT), rapidly determines a skin lesion’s depth and potential malignancy, without using a scalpel (Skin Res. Technol. 10.1111/srt.12712).
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 don’t 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.
VOCT creates a 3D map of the lesion’s width and depth under the skin using a tiny laser diode. It also uses soundwaves to assess the lesion’s density and stiffness, since tumours and cancer cells are stiffer than normal tissues. An inch-long speaker applies 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,” says lead researcher Frederick Silver. “It’s a significant improvement over surgical biopsies, which are invasive, expensive and time consuming.”
The researchers tested the device over six months on four skin excisions and eight volunteers without skin lesions. They found that precancerous and cancerous lesions were characterized by changes in both the morphology and stiffness of the cellular components of the skin. The prototype VOCT device, which awaits FDA approval for large-scale testing, could accurately distinguish benign and cancerous or precancerous lesions compared with normal skin and scar.
Further studies are needed to fine-tune the device’s ability to identify a lesion’s borders and areas of greatest density and stiffness, which would allow physicians to remove tumours with minimally invasive surgery.
