Reviewed by Tanya Das
It used to be that a cancer diagnosis was akin to a dreaded death sentence. Today, steady changes in living habits have drastically decreased mortality rates, and billions have been spent on cancer research to find treatments and possible cures. Progress has been slow, but the recent, innovative SpectroPens, devices able to detect cancer cells, may shed more light on how to battle uncontrolled cell growth.
Traditional surgical procedures are called invasive surgery, because the removal of uncontrolled cells can pose a threat to nearby organs. The incision process relies on the surgeon’s ability to approximate the location of cancer cell growths from pre-operation scans, but this often leaves leftover cancer cells that grow into another tumor. Finding these tumors is difficult; normal tissue and cancerous tissue all look the same to the eye, and during operation, other methods such as positron emission tomography and magnetic resonance imaging are impossible. Additionally, traditional surgical procedures for cancer have a high-risk factor if the operation is on a vital organ and the organ is damaged by the cutting method.
The SpectroPen is a recently developed alternative to traditional surgery; news concerning them was released in October 2010 by the Emory University School of Medicine, Georgia Institute of Technology, and the University of Pennsylvania through the journal Analytical Chemistry. This device, which is handheld like a pen and thus fitting to its name, uses a near-infrared laser and a light detector, and transmits fluorescence and Raman signals (associated with vibrations of a molecule that reveal its geometry) to a spectrometer through a fiber optic cable.
SpectroPens work by detecting dyes or agents that bind to cancerous cells. First, particles that consist of a dye (such as indocyanine green), gold that amplifies the dye, and an antibody that binds to the surface of tumor cells more than that of normal cells are injected into the body. These particles collect rapidly in tumor cells due to the presence of leaky blood vessels around tumors. When a SpectroPen shines on tissue, the device’s near-infrared radiation causes the dye to emit a strong glow, and the gold particles produce surface-enhanced Raman scattering signals, which amplify the fluorescence of the dye. The amplified glow resulting from Raman signals strongly differentiates between normal and cancerous cells. This signal data is then transmitted to the spectrometer, after which it can be analyzed to pinpoint the location and size of tumors smaller than 1 millimeter.
Compared to invasive surgery, SpectroPens seem more promising in ensuring precision. SpectroPens are currently undergoing further laboratory tests, and with in-vivo tests already in development, the device could be used in a few years in real-time operation rooms. The James Provenzale of University of Georgia of Veterinary Medicine is currently using SpectroPens to operate on dogs, and clinical trials are in motion at the University of Pennsylvania School of Medicine under the direction of Sunil Singhal; if the device lives up to its expectations, a breakthrough in cancer research may also be close at hand.
After billions of dollars spent in cancer research, the SpectroPen may provide insights on reaching higher success rates for operations, and may become the biggest breakthrough in cancer research yet. The battle against cancer, as persistent as the disease itself, will not be ending anytime soon, but the SpectroPen is a step forward - perhaps soon to be live at the nearest operation room.
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