Researchers from the University of Texas at Austin's Cockrell School of Engineering have developed a new method that uses light probes to detect cancerous skin lesions. This 3-in-1 spectroscopy probe uses one device to modulate light in three different ways to measure the properties of skin tissue and detect cancer. This instrument has been described in a paper published in the journal Review of Scientific Instruments, from AIP Publishing.

Tanning is the leading cause of skin cancer. In fact, it has often been considered a sort of addiction, similar to substance abuse. A 2006 study in the journal Cell showed that frequent tanners experienced withdrawal symptoms when they were given a substance to block the endorphins produced by the skin when exposed to UV rays. Whether it’s by sitting out in the sun or using a tanning bed, there is overwhelming evidence that suggests tanning of skin unprotected by lotions greatly increases the chance of skin cancer.

Skin cancer, especially melanoma, is one of the leading causes of cancer deaths in America, and nearly 10,000 people fall prey to it each year. If detected at an early stage, they can be removed and cause little damage. But untreated carcinomas can penetrate the skin layers or even spread to distant organs, making it potentially fatal.

Skin cancers are currently detected by performing biopsies — that is examining a tissue sample from unnatural lesions or warts on the skin, microscopically. But determining which lesion to examine can be quite ambiguous, since for every case of skin cancer detected there are roughly 25 negative biopsies performed. Since the cost of testing does not come cheaply, it leads to a huge financial burden.

The new probe developed can help reduce the high number and cost of negative biopsies by giving a clear picture, of which skin lesions are most likely cancerous, say the researchers. The device combines three spectroscopy techniques: Raman spectroscopy, diffuse reflectance spectroscopy, and laser-induced fluorescence spectroscopy to accurately probe and give detailed analysis of a skin lesion.

"As normal skin becomes cancerous, cell nuclei enlarge, the top layers of skin can thicken and the skin cells can increase their consumption of oxygen and become disorganized," said James Tunnell, the chief researcher, in a press release. "The changes alter the way light interacts with the tissue."

These changes can be detected only through multiple spectroscopic techniques. For example, diffuse optical spectroscopy can detect light absorbed by proteins such as hemoglobin while Raman spectroscopy can detect the vibrational modes of chemical bonds, such as those found in connective tissues, lipids, and cell nuclei.

The whole device is compact and portable. The probe itself is about the size of a pen and the spectroscopic and computer equipment that supports it all fit into a utility cart that can be wheeled between rooms. Each reading takes about 4.5 seconds to perform. The 3-in-1 nature of the probe saves time and money while still giving a comprehensive examination of the skin properties.

"Skin is a natural organ to apply imaging and spectroscopy devices to because of its easy access. This probe that is able to combine all three spectral modalities is the next critical step to translating spectroscopic technology to the clinic," Tunnel said in the statement.

The researchers have already begun testing their device in pilot clinical trials and are attempting to bring the device to dermatologists’ offices with the help of funding agencies to help detect skin cancers at early stages that might greatly reduce the fatality associated with this condition. 

Source: Sharma, M, Marple E, Reichenberg J, Tunnell J, Design and characterization of a novel multimodal fiber-optic probe and spectroscopy system for skin cancer applications. Review of Scientific Instruments. 2014.