Doctors need to identify a mole that may be melanoma at an early, treatable stage. To do this, doctors now look for subjective clues such as the size, shape and colouring of a mole, but the process is not perfect. Rhoda Alani, professor and chair of dermatology at the Boston University School of Medicine, said: “Our goal is to give an objective measurement as to whether a lesion may be malignant. It could take much of the guesswork out of screening patients for skin cancer.”
With this goal in mind, the research team aimed its research at measuring heat differences just below the surface of the skin. Because cancer cells divide more rapidly than normal cells, they typically generate more metabolic activity and release more energy as heat. To detect this, the researchers use a highly sensitive infrared camera. Normally, the temperature difference between cancerous and healthy skins cells is extremely small, so the scientists devised a way to make the difference stand out.
First, they cool a patient’s skin with a one-minute burst of compressed air. When the cooling is halted, they 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 this difference can be captured by the infrared camera and viewed through image processing.
The researchers have begun a pilot study of 50 patients to help determine how specific and sensitive the device is in evaluating melanomas and precancerous lesions. To test it, dermatologist-identified lesions undergo thermal scanning with the new system, and then a biopsy is performed to determine whether melanoma is actually present. Further patient testing and refinement of the technology are needed.
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, they said.
MEDICA.de; Source: Johns Hopkins University