Infrared device tested to detect melanoma early
Scientists from Johns Hopkins are testing an infrared device to help detect skin cancer, the most deadly of which is melanoma, that affects 68,720 individuals annually according to the National Cancer Institute. Melanoma can kill, and the infrared device could have profound benefits for detecting skin cancer early and non-invasively.
Finding melanoma is not easy, and relies on appearance such as dark color, irregular edges, and changes in skin moles that may have been present for years. Biopsy confirms the diagnosis. Melanoma can also hide under the fingernails, in the groin, on the scalp, and on the back where many individuals may neglect to look.
"The problem with diagnosing melanoma in the year 2010 is that we don't have any objective way to diagnose this disease," said Rhoda Alani, adjunct professor at the Johns Hopkins Kimmel Cancer Center and professor and chair of dermatology at the Boston University School of Medicine. "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."
The infrared device uses a unique way to detect melanoma. Cancer cells on the skin emit more heat than healthy tissue, but the difference is very subtle. The researchers at Johns Hopkins first cool the skin with compressed air, then record temperature changes in the suspicious area over two to three minutes. Cancer cells reheat more quickly. Then images are captured on camera.
"The system is actually very simple. 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", says heat transfer expert Cila Herman, a professor of mechanical engineering in Johns Hopkins' Whiting School of Engineering who has teamed up with Dr. Alani for the project. The current study has enrolled 50 patients to determine if the infrared system can work for finding melanoma early.
"Obviously, there is a lot of work to do," Herman said. "We need to fine-tune the instrument -- the scanning system and the software -- and develop diagnostic criteria for cancerous lesions. When the research and refinement are done, we hope to be able to show that our system can find melanoma at an early stage before it spreads and becomes dangerous to the patient."
Dr. Alani is optimistic, but cautiously so. She warns that the infrared device would not replace a dermatologists diagnosis for suspicion of melanoma, but envisons "that this will be useful as a tool in helping to diagnose early-stage melanoma." The hand held device could also be developed into a full body scanner to screen patients with multiple skin lesions for melanoma that when detected early would save lives. So far, all of the melanomas in the patients studied were detected with the infrared scanner.