14 DAY TRIAL // Researchers at the University of California, Irvine (UC Irvine), have been developing a new LED device that could help advance photodynamic therapy for skin cancer.
They are experimenting novel ways to image cancerous lesions by using LEDs, and hope to develop a technique that could treat cancer, called photodynamic therapy, or PDT.
The principle of PDT is to inject photosensitizing chemicals that absorb light into a tumor, and then expose this tumor to light, while waiting for the chemicals to generate oxygen radicals and destroy the cancer cells.
The United States Food and Drug Administration (FDA) approved this technique for treating esophageal and lung cancer, but there are scientists that believe the method could also be used in treating skin cancer.
Rolf Saager works in the laboratory of Anthony Durkin at the Beckman Laser Institute at UC Irvine in collaboration with Kristen Kelly, MD, and Modulated Imaging Inc., and he believes that PDT could also be very useful against skin cancer.
The only problem is that there is no detailed imaging technique sensitive enough to target and monitor the effectiveness of the photodynamic therapy.
Thinking of ways to solve this problem, the researchers focused on a technique called spatial frequency domain imaging, that uses LEDs.
They designed a new device with a set of five different colors of LEDs, that lights up the skin with different intensity patterns, that can change depending on the pigments of the skin and on the structure of the tissue.
Adding appropriate models of light propagation to this device, the biochemistry of the tissue becomes visible.
Saager said that “through this imaging modality, it is now possible to assess how the therapeutic light will travel throughout the affected tissue, quantify the drug present within the lesion and monitor its efficacy during treatment.”
In order to test the new system, the researchers imaged a small group of people suffering from skin cancer, before they started treatment.
In five to ten seconds, they had images with a resolution of 30 microns, who mapped precisely the optical properties of the lesions, the tissue oxygenation and the quantitative distribution of the new drug.
The scientists now hope that their research would open the way to a therapy for basal cell carcinoma, which is the most common form of skin cancer.
Their work will be presented at the Optical Society's (OSA) 94th annual meeting, Frontiers in Optics (FiO) 2010 at the Rochester Riverside Convention Center in Rochester, New York, from Oct. 24-28.