Multispectral LEDs shed light on oral cancer

By Kathy Kincade, Editor in Chief
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December 15, 2011 -- Multispectral imaging has long been used for space-based analysis of environmental conditions, crop management, and urban growth. Can this same advanced technology improve the ability to detect oral and skin cancers?


A Canadian medical device company with roots in terahertz imaging thinks so. Verisante Technology -- a public company formerly known as T-Ray Science -- has licensed multispectral imaging technology developed by researchers from the British Columbia Cancer Agency (BCCA) and is now developing a prototype for clinical testing in the detection of oral and skin cancers.

“This technology is designed to raise specificity so you don't get as many false positives.”
— Thomas Braun, CEO, Verisante
     Technology

Verisante's goal is to create a low-cost, user-friendly device that can identify cancerous lesions in the epithelial layer of tissue with more sensitivity and specificity than existing cancer detection methods.
"It will be like a digital camera with LEDs [light-emitting diodes] of different wavelengths that will take measurements from the reflected light and analyze the spectral fingerprint to give the practitioner an on-the-spot answer on whether they are looking at a high- or low-risk lesion and whether or not they should do a biopsy," said Thomas Braun, CEO of Verisante. "This technology is designed to raise specificity so you don't get as many false positives."
The system will use LEDs operating in several wavelengths to measure changes in the scattering properties of tissue and thus detect suspicious cellular changes, according to Haishan Zeng, PhD, a senior scientist in the BCCA's Integrative Oncology Department and co-inventor of the technology.
"Multispectral imaging is reflectance-based, so what you are getting is information about chromophores in the tissue," Zeng said. "The goal for us is to help identify suspicious lesions and to determine which lesions to biopsy and which location in the lesions to biopsy."
Attractive price point
In the past year Verisante has acquired the rights to two dozen patents and patents pending for cancer detection technologies, including white light reflectance imaging, fluorescence imaging, rapid Raman spectroscopy, and rapid multispectral imaging. The company's flagship product is a rapid Raman imaging system for detecting skin cancer that could also be used in the oral cavity.
While the Raman technology offers advantages over multispectral imaging in terms of sensitivity and specificity, it is also more expensive, which could make it a tougher sell in the dental market, according to Braun.
"The Raman system is expected to retail for $60,000," he said. "The trouble with developing a Raman dental probe and then doing a clinical study and getting all the regulatory approvals is that the only people who are willing to pay $60,000 are major medical centers."
The price point for the multispectral device is expected to be less than $5,000, he noted.
"The ideal would be to combine the multispectral and Raman imaging devices, but not everyone can afford the Raman system," Zeng said. "And in a lot of cases, multispectral can be quite good and very useful."
Zeng is now working with Verisante on the multispectral prototype.
"What we are trying to do is build a better, cheaper, more reliable instrument, with better ways to gather data," Zeng said. "We are developing physical modeling to extract the information from the image data."
Once the prototype is ready, Verisante will conduct a clinical trial, apply for Health Canada approval, obtain the European CE Mark, and then approach the U.S. Food and Drug Administration to file for 510(k) clearance, according to Braun. The company is already certified by the International Organization for Standardization (ISO) as a medical device manufacturer, he noted.
Another multispectral device
Verisante is not alone in its belief that multispectral imaging has a place in oral cancer detection. The Identafi oral cancer screening device -- originally developed by Trimira but acquired earlier this year by DentalEZ -- uses a combination of white, violet, and green-amber multispectral wavelengths to detect biochemical and morphological changes in the cells of the mouth, throat, tongue, and tonsils that may potentially lead to oral cancer.
Identafi is intended for use by dentists, hygienists, and oral surgeons and sells for about $3,200. An insurance code exists for the screening procedure, according to DentalEZ, and about 40% of insurers are currently reimbursing for this procedure.
But Braun believes the Verisante device will be a "quantum leap" forward from the Identafi and other commercially available cancer screening and detection products.
"What we are trying to do is come up with something that yields spectroscopic quality at a much lower price," he said. "A lot of medical devices can cause anxiety for the patient, but we want these products to be approachable. Ultimately, we want to be the Apple of medical devices."