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• Posted April 12, 2024

'Virtual Biopsy' Tests Skin Lesions Without a Scalpel

Folks with a suspicious-looking mole or questionable skin lesion often have to endure a scalpel or shaver so their doctor can cut off a sample to send in for biopsy.

But a new, noninvasive “virtual biopsy” might soon allow doctors to instead scan the spot to determine if it contains any cancer cells, researchers at Stanford Medicine report.

The new method, which measures how light waves from a laser bounce off human tissue, works in much the same way as ultrasound uses sound waves to visualize organs, researchers said.

And while it will be useful in dermatology, the new scan could also help doctors detect cancer in other ways, they added.

For example, surgeons could use the scan during breast cancer surgery to make sure they've removed all of a tumor, rather than waiting on a pathologist to analyze the tissue later.

“We've not only created something that can replace the current gold-standard pathology slides for diagnosing many conditions, but we actually improved the resolution of these scans so much that we start to pick up information that would be extremely hard to see otherwise,” said senior researcher Adam de la Zerda, an associate professor of structural biology at Stanford.

A former graduate student in de la Zerda's lab, Yonatan Winetraub, developed the method. Winetraum now leads his own research lab at Stanford focusing in part on virtual biopsies.

“This has the potential to transform how we diagnose and monitor concerning skin lesions and diseases in the clinic,” co-researcher Dr. Kavita Sarin, an associate professor of dermatology, said in a Stanford news release.

Typically, a pathologist slices biopsied tissue into thin layers and treats them with chemicals that highlight the patterns, shapes and structures of cells.

Preparing these slides take a lot of work, and it does irreversible damage to the biopsied tissue. Once a biopsy is sliced in one direction, for example, it can't be sliced another way to provide a different view.

The new technique involves a technology called optical coherence tomography (OCT).

OCT scans typically are used by eye doctors to examine the back of the eye, but de la Zerda and Winetraub enhanced the scans so they would work in other organs as well.

Better hardware, new processing methods and artificial intelligence have all helped transform OCT into a better, more useful scanning technique.

“We kept improving and improving the quality of the image, letting us see smaller and smaller details of a tissue,” de la Zerda said. “And we realized the OCT images we were creating were really getting very similar to [pathology slides] in terms of what they could show.”

Three Stanford dermatologists presented with random assortments of OCT images and pathology slides found they could detect cellular structures just as well with either, researchers said.

With this new technology, dermatologists won't have to wait to see if an unusual spot on a person's skin grows or changes before acting, de la Zerda said.

“Imagine if we could give physicians the ability, right there in the room with the patient, to take out an OCT camera and -- rather than slice the patient up in dozens of places -- image the cells inside each mole,” de la Zerda said.

Similar benefits could come with cancer surgery.

Researchers noted that about 20% of breast cancer patients require a second surgery because the first doesn't completely remove their cancer. OCT images produced in the operating room could help doctors detect missed cancer cells and avoid additional surgeries.

The new study was published April 10 in the journal Science Advances.

More information

The National Institutes of Health have more about skin biopsy.

SOURCE: Stanford Medicine, news release, April 10, 2024