New imaging system could mean near-instant biopsy results: News Center

September 27, 2022

Tissue biopsy with a new imaging system based on 2-photon fluorescence microscopy (TPFM) shows promising results. The system, described in the journal JAMA Dermatology, was developed by University of Rochester biomedical engineer Michael Giacomelli. (Photo courtesy of Giacomelli Laboratory)

Biopsies have been performed the same way since the 19th century, but new technology could allow for point-of-care skin cancer diagnosis.

Medicine has made spectacular progress over the past century. But when it comes to getting biopsy results, very little has changed. Consider, for example, what happens when a patient presents for a skin biopsy for non-melanoma skin cancer.

“The surgeon will remove a small piece of skin,” says Michel Giacomellilecturer in biomedical engineering and optics at the University University of Rochester. “Someone in pathology will look at it weeks or even a month later under a microscope. And then, depending on what they find, the patient is told that it’s fine, don’t worry, or you have to that you come back for a second appointment so that we can treat you.

Giacomelli is developing a new imaging system, contained on a portable cart, to shorten this process to two minutes. This would allow a surgeon to immediately determine if the lesion is cancerous and, if so, “treat the patient in the same visit instead of spreading it out over the next month and multiple visits.”

The system – using two-photon fluorescence microscopy (TPFM) – demonstrated remarkable accuracy in a pilot study summarized recently in JAMA Dermatology. When tested on 15 biopsies of known non-melanoma skin cancer, the technology was able to detect basal cell carcinoma with perfect accuracy (sensitivity and specificity of 100%) and squamous cell carcinoma with high accuracy (sensitivity of 89 % and specificity of 100%).

Non-melanoma skin cancer is the most common type of human cancer, with more cases per year than all other types of cancer combined in the United States. Eighty percent of non-melanoma skin cancers are basal cell carcinomas.

Applications in “all kinds of scenarios”

Typically, the biopsied tissue is excised, fixed, paraffin (preserved), stained and mounted on slides before being evaluated by a dermatopathologist. “That’s how it’s been since the end of the 19th century,” says Giacomelli. “Billions and billions of biopsies have been performed this way. Everyone is on the same page; It works very well. The problem is that it is very slow.

Giacomelli is now working closely with Associate Professor of Dermatology Sherrif Ibrahim on a follow-up study of 200 patients of the imaging system.

Even when tissue is quickly frozen for faster analysis, surgeons can wait an hour or more for biopsy results to be sure they have completely removed a malignant tumor from a patient still on the operating table. This monopolizes the surgeon’s time and the operating room, while disrupting workflow in busy pathology departments.

Giacomelli sees potential applications for his system in providing rapid biopsy results for all kinds of diseases. “There are all kinds of scenarios,” he says.

For example, “in prostate cases, surgeons often have a very poor idea of ​​what they’re getting into based solely on a prior X-ray or MRI,” says Giacomelli. “You see random cases where they remove the prostate, and sometimes there’s an obvious tumor that has spread beyond the prostate, or other times it’s very localized. This technology provides the ability to adjust patient treatment on the fly. »

The benefit of using TPFM is that it not only generates high-resolution images, but it also uses near-infrared light that penetrates deeper through tissue, making it “advantageous for imaging fresh, irregularly shaped biopsies quickly with minimal preparation,” the article notes. .

Giacomelli now works closely with Cherif Ibrahimassociate professor of dermatology at the university’s medical center, on a larger follow-up study of 200 patients, using randomly collected biopsy specimens at Ibrahim Rochester Dermatology Surgery in Victor, New York.

“The goal is to analyze how the technique works in a real scenario, where many people arrive and all kinds of things can appear,” says Giacomelli. “We really want to make sure there isn’t something weird that normally has nothing to do with cancer that we somehow confuse with cancer or something that has something to do with it. something to do with cancer but that we can’t imagine. You never know what you’re going to find once you start taking random biopsies of people.

Using TPFM imaging to guide surgeries?

Giacomelli has also embarked on a parallel study to see if a new system he developed incorporating TPFM and video can be used to guide surgeries.

The system overlays TPFM images of the site where the tissue is removed onto a webcam image, co-registering what it looks like on the eye with what it would look treated on a slide. “You can show what the excised tissue looks like and how much tumor is on the excision,” says Giacomelli. “They can then map that into the wound they are creating in order to decide which side to cut.”

In addition to Ibrahim, other co-authors of JAMA Dermatology The study includes Vincent Ching-Roa and Chi Huang, graduate students in Giacomelli’s lab, and Bruce Smoller, professor of pathology and laboratory medicine.

The National Institutes of Health funded the project.

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Key words: Department of Biomedical Engineering, Department of Dermatology, featured, Hajim School of Engineering and Applied Science, Institute of Optics, Michael Giacomelli, Sherrif Ibrahim

Category: Featured, Science and Technology

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