Laser Imaging System Targets Oral Cancer

A new laser probe not only looks promising for early detection of oral cancer but also could be used during surgery to locate the edges of a tumor.

Researchers at UC Davis Health System in Sacramento, California, developed the fiber-optic probe. The lab of Laura Marcu, PhD, a professor of biomedical engineering at UC Davis, collaborated with a team led by Gregory Farwell, MD, in the otolaryngology department at the UC Davis Cancer Center.

The probe uses a laser to stimulate molecules in the patient’s tissues. Some molecules respond by reemitting fluorescent light. The device detects and analyzes this light, using time-resolved light induced fluorescence spectroscopy (TR-LIFS) to determine the types of molecules.

Approximately 43,000 people in the United States are diagnosed with tumors of the mouth, pharynx, or larynx each year. The main risk factor is tobacco use, though a recent increase in cases has been linked to human papillomavirus. The UC Davis researchers hope their new probe will lead to earlier detection; currently, few cases are diagnosed at an early stage.

“There’s a lot out there about breast, prostate, and brain cancer, but people are not so aware about oral cancer and its devastating consequences,” said Dr. Marcu, as quoted in a UC Davis news release. “People don’t think to look for it, and there isn’t any routine screening.”

The probe can also assist surgeons in real time. During surgery, blood can distort the intensity of the fluorescence but not its duration. By measuring changes in fluorescence over time, surgeons can see the tumor margins even as they are cutting the tissue.

The researchers used the probe on nine human volunteers who underwent surgery at the UC Davis Medical Center for mouth, throat, or larynx cancer. A comparison of TR-LIFS readings with biopsy samples from the same locations found that the probe could accurately diagnose cancer in the surgical environment.

Details of the study are to be published in an upcoming issue of the journal Otolaryngology—Head and Neck Surgery.

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