McKelvey School of Engineering

Imaging technology could better monitor tumor growth, drug effectiveness

This image shows the growth dynamics of 3D tumor spheroids measured with optical coherence tomography (OCT), a type of optical imaging technology that Chao Zhou is using in his lab.

More than 90% of drugs in development never make it to market after failing in the testing process, either in cells in the lab, in small animals or in humans. A biomedical engineer in the McKelvey School of Engineering at Washington University in St. Louis plans to improve on an existing imaging method that will give researchers more insight into the effects of drug candidates on tumor models over time.

To achieve this goal, Chao Zhou, associate professor of biomedical engineering, plans to use optical coherence tomography (OCT), a type of optical imaging technology that has been used for two decades in ophthalmology to take images of the retina. He will develop an improved version of the method to penetrate into 3D tumor models to determine the effect of drugs on their growth with a three-year, $855,305 grant from the National Institutes of Health’s National Institute of Biomedical Imaging and Bioengineering.

Existing imaging technology measures drug efficacy on two-dimensional cell culture and can only see the surface of a tumor sample. However, tumors are three-dimensional. With existing technology, light cannot penetrate the depth of the tumor. In addition, researchers have to stain the sample to see it on a microscope, which destroys the sample.

“With the OCT technology, we can image cells up to 1 to 2 millimeters deep,” Zhou said. “That way we can see the surface as well as the center of the tumor and monitor it over time, say 3 to 4 weeks, to see how the tumor spheroid is growing and developing.”

“This is important because the only other way to evaluate the internal structure of a tumor spheroid is to cut it open and see what’s going on,” Zhou said. “With this technology, we can follow the same tumor spheroids and see how they respond to different drug treatment.”

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