The ability to analyze a skin tumor non-invasively could make biopsies much less risky and distressing to patients, researchers say.

Currently, physicians who perform surgical biopsies often don’t know the extent of a lesion–or the necessity of referring 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 lesion’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. It’s a significant improvement over surgical biopsies, which are invasive, expensive, and time-consuming,” says Frederick Silver, a professor of pathology and laboratory medicine at Rutgers Robert Wood Johnson Medical School, and lead researcher of the paper in Skin Research & Technology.

A prototype VOCT device accurately distinguished between healthy skin and different types of skin lesions and carcinomas, the study shows. 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, which would allow physicians to remove tumors with minimally invasive surgery.

The researchers are currently waiting for FDA approval for large-scale testing. Additional researchers are from Rutgers, the Neigel Center for Cosmetic and Laser Surgery, and the Center for Advanced Eye Care.