ASU, Banner Team Creates Gel To Measure Radiation Exposure During Treatment

By Nicholas Gerbis
Published: Friday, November 15, 2019 - 12:22pm
Updated: Friday, November 15, 2019 - 2:54pm
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Radiation therapy provides treatment and relief for many with cancers and other diseases. But too much radiation can cause serious illnesses or death. A new detector could offer a better way to monitor exposure.

The research appears in the journal Science Advances.

Overexposure to radiation can result from medical mistakes, but it can also arise from equipment errors.

Dosimeters can help ensure radiation goes only where it's needed and in the proper doses. Unfortunately, many devices measure dosage only at a single point, don't conform well to the body's curves and take too long to deliver results.

Co-author Kaushal Rege, a professor of chemical engineering in Arizona State University's Ira A. Fulton Schools of Engineering, said his group's gold nanogel overcomes these limitations.

"It can detect radiation in a spatial manner. So, if there's different doses at different locations, this device, if you will, has the ability to detect that," he said.

ASU partnered with the Banner MD Anderson Cancer Center in Gilbert to develop the dosimeter.

When gold ions in the gel encounter ionizing radiation, they become gold nanoparticles and produce a color, the intensity of which corresponds to the radiation level.

The color is produced by a property called plasmonics. In plasmonic materials, electrons resonate with certain kinds of electromagnetic radiation, which often have wavelengths bigger than the materials' particles. As the electrons absorb that energy and oscillate, they absorb or scatter light at different wavelengths.

The color's intensity is then measured using absorbance spectroscopy, a technique for analyzing samples based on the wavelengths they absorb.

The gel is still in lab tests and has far to go before it could potentially see human use. Researcher have thus far tested its effectiveness on canines undergoing clinical radiation therapy.

Science