Raman Spectroscopy Could Improve Oral Cancer Diagnostics

According to research from the University Medical Center Hamburg-Eppendorf, Raman spectroscopy may provide early detection of oral squamous cell carcinoma. One of the most common cancers, oral squamous cell carcinoma is often undetected until a late stage.

Currently, clinically apparent, conspicuous mucosal lesions of the oral cavity require initial conservative treatment and monitoring. If they persist, surgical biopsy is used to make a diagnosis.

“Our study shows the potential of Raman spectroscopy for revealing whether a lesion is cancerous in real time,” said research team leader Levi Matthies. “Although it won’t replace biopsies any time soon, the technique could help reduce the lapse of valuable time as well as the number of invasive procedures.”

A new study shows that Raman spectroscopy could aid in early detection of oral squamous cell carcinoma. The work was performed with a compact portable Raman sensor designed by the researchers. Courtesy of Levi Matthies, University Medical Center Hamburg-Eppendorf.

The researchers used a variation of Raman spectroscopy known as SERDS (shifted excitation Raman difference spectroscopy), which is capable of analyzing tissues that exhibit strong background fluorescence. To test the method, they designed a compact and portable Raman sensor consisting of a tunable diode laser, a fiber-coupled spectrometer, and a Raman probe. The scientists used the device to analyze unlabeled biopsy samples from 37 patients at 180 measurement locations.

To classify the raw data, the team trained and tested computer models, ultimately distinguishing oral squamous cell carcinoma from nonmalignant lesions with an accuracy of over 88%, and from healthy tissue with an accuracy of over 89%. The majority of spectral features used to distinguish malignant and nonmalignant lesions came from protein and nucleic acid molecules.

“Our results show that this approach is a promising candidate for objective, chair-side diagnosis of oral cavity lesions in real time without the addition of labeling agents,” Matthies said. “It could help reduce the diagnostic gap between clinical exam and invasive biopsy.”

With further development, the researchers say the approach could be expanded to aid in the classification of precancerous conditions, grading the severity of dysplastic tissue aberration and distinguishing various oral lesion subtypes. Currently, the researchers are working to increase the speed of the method to support real-time diagnosis.

The research was published in Biomedical Optics Express (www.doi.org/10.1364/BOE.409456).