Prototype for Acoustic Detection of Melanomas

Researchers from Washington University in St. Louis have developed a prototype for a hand-held melanoma scanner. Melanoma is the fifth most common form of cancer in the US. It is the deadliest of the skin cancers, causing more than 75 percent of skin cancer deaths. The prognosis for patients over 70 is especially grim; according to one study, “Five-year disease-specific mortality and overall mortality are both worse for these patients.”

One of the contributing factors to the mortality rate is that it is hard to properly detect the thickness of melanoma tumors; thicker tumors are more likely to spread (one factor that contributes to the bad prognosis for the elderly), so better screening should potentially save lives.

Prototype of handheld melanoma probe.  Image courtesy of Yong Zhou,

Prototype of handheld melanoma probe. Image courtesy of Yong Zhou.

The Washington University device uses lasers and sound waves to detect the volume of tumors. As described in a press release from the Optical Society, “the technique relies on the photoacoustic effect, in which light is converted into vibrations. In the case of the new device, a laser beam shines into the skin at the site of a tumor. Melanin, the skin pigment that’s also in tumors, absorbs the light, whose energy is transferred into high-frequency acoustic waves. Unlike light, acoustic waves don’t scatter as much when traveling through skin. Tumor cells will produce more melanin than the surrounding healthy skin cells, and as a result, the acoustic waves can be used to map the entire tumor with high resolution. The device has a detector that can then turn the acoustic signal into a three-dimensional image on a screen.”

“The device is essentially ready for commercialization,” according to engineer Lihong Wang, one of the paper’s co-authors. There’s just one catch: It hasn’t yet undergone clinical trials, which could mean anywhere from an 18-month to a nearly five-year delay, depending on how long it takes the FDA to approve their trial design and for them to recruit subjects.

However, if we join in the researcher’s optimism, the device should help give oncologists a non-invasive way to estimate tumor volume that will be more accurate than a biopsy.