Researchers at Johns Hopkins University (JHU) have developed a noninvasive infrared scanning system to help doctors determine whether pigmented skin growths are benign moles or melanoma, a potentially lethal form of cancer. The prototype system looks for the tiny temperature difference between healthy tissue and a growing tumor. The researchers have begun a pilot study of 50 patients at JHU to help determine how specific and sensitive the device is in evaluating melanomas and precancerous lesions. If the system works as envisioned, it could help physicians address a serious health problem by identifying a mole that may be melanoma at an early, treatable stage. Currently, doctors look for subjective clues such as the size, shape and coloring of a mole, but “we don’t have any objective way to diagnose this disease,” says Rhoda Alani, MD, adjunct professor at JHU’s Kimmel Cancer Center and professor and chair of dermatology at Boston University School of Medicine. “Our goal is to give an objective measurement as to whether a lesion may be malignant, [which] could take much of the guesswork out of screening patients for skin cancer.”
Alani has teamed with heat transfer expert Cila Herman, professor of mechanical engineering in JHU’s Whiting School of Engineering, who is developing new ways to detect subsurface changes in temperature. Because cancer cells divide more rapidly than normal cells, they typically generate more metabolic activity and release more energy as heat. Herman uses a highly sensitive infrared camera to detect subtle temperature differences between cancerous and healthy skins cells. The researchers cool a patient’s skin with a harmless one-minute burst of compressed air, then immediately record infrared images of the target skin area for two to three minutes. Cancer cells typically reheat more quickly than the surrounding healthy tissue, and the difference can be captured by the infrared camera and viewed through sophisticated image processing.
“The system is actually very simple,” Herman says. “An infrared image is similar to the images seen through night-vision goggles. In this medical application, the technology itself is noninvasive; the only inconvenience to the patient is the cooling.”
In the pilot study, dermatologist-identified lesions undergo thermal scanning with the new system, then a biopsy is performed to determine whether melanoma is actually present. “We, at this point, are not able to say that this instrument is able to replace the clinical judgment of a dermatologist, but we envision that this will be useful as a tool in helping to diagnose early-stage melanoma,” Alani says. The researchers envision a hand-held scanning system that dermatologists could use to evaluate suspicious moles. The technology also might be incorporated into a full-body scanning system for patients with a large number of pigmented lesions. The skin cancer scanning system is protected under an international patent application submitted by JHU’s TTO, which has engaged in talks with investors and medical devices firms concerning possible licensing deals.
Source: EurekAlert!