Johns Hopkins researchers have developed a noninvasive infrared scanning system to help doctors determine whether pigmented skin growths are benign moles or melanoma, a lethal form of cancer.
The prototype system works by looking for the tiny temperature difference between healthy tissue and a growing tumor.
The researchers have begun a pilot study of 50 patients at Johns Hopkins to help determine how specific and sensitive the device is in evaluating melanomas and precancerous lesions. Further patient testing and refinement of the technology are needed, but if the system works as envisioned, it could help physicians address a serious health problem: The National Cancer Institute estimated that 68,720 new cases of melanoma were reported in the United States in 2009; it attributed 8,650 deaths to the disease.
To avert such deaths, 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 coloring of a mole, but the process is not perfect.
“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.”
With this goal in mind, Alani teamed with heat transfer expert Cila Herman, a professor of mechanical engineering in Johns Hopkins’ Whiting School of Engineering. Three years ago, Herman obtained a $300,000 National Science Foundation grant to develop new ways to detect subsurface changes in temperature. Working with Muge Pirtini, a mechanical engineering doctoral student, Herman aimed her 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. …