Light-scattering method could gauge patient response to chemotherapy

Using Doppler light scattering, researchers can determine how a patient will respond to chemotherapy, even before beginning treatment.

Content Dam Bow Online Articles 2018 04 Kody Childress Web

Recognizing that less than half of cancer patients respond favorably to chemotherapy, a team of researchers at Purdue University (West Lafayette, IN) has developed a light-scattering method for testing how patients will respond to various drugs—which could pave the way for more personalized treatment. Using Doppler light scattering, the researchers can determine how a patient will respond to chemotherapy, even before they begin treatment.

Related: Optical imaging system could ID breast cancer patients who will benefit most from chemotherapy

"Doppler weather radar sends electromagnetic waves into clouds, and while you don't see individual rain droplets, you pick up the overall motion of the raindrops. What you create with this is a 3D map of cloud motion," says David Nolte, the Edward M. Purcell Distinguished Professor of Physics and Astronomy at Purdue University. "We're looking at the motion inside living tissue rather than rain droplets, and we're using infrared light instead of radar. It's like watching the weather inside living tissue as the tissue is affected by cancer drugs."

Tiny chunks of tissue taken from a biopsy are placed in a multiwall plate, where various drugs are applied. Light from an LED shines into the middle of the tissue, and researchers look at the scattered light coming off.

In collaboration with John Turek, professor of basical medical sciences, and Mike Childress, associate professor of veterinary medicine, Nolte has built a library of data to associate various light patterns with the corresponding response of patients to treatment.

In a paper describing the work, the team reported an 84% success rate predicting patient response to therapy in its first complete preclinical trial.

The study was performed on 19 dogs previously diagnosed with B-cell lymphoma, which is molecularly and clinically similar to lymphoma in humans. The treatment of cancer in dogs is almost identical to treatment for humans, Nolte says. They have biopsies, go through chemotherapy, and come back for follow-ups.

Content Dam Bow Online Articles 2018 04 Kody Childress Web
Kody experienced prolonged survival following chemotherapy, with help from Mike Childress, an associate professor of comparative oncology at Purdue. This positive outcome was predicted by a novel biodynamic imaging test. Carolyn McGuire, Kody's owner, is shown here with the two. (Photo credit: Purdue University/Kevin Doerr)

The method for testing patient response to therapy, biodynamic digital holography, is currently in clinical trials in human ovarian, breast, and esophageal cancer. These trials are proceeding with similar levels of accuracy, Nolte says.

Attempts to create strategies for predicting patient response to chemotherapy have been made in the past. These older methods broke up tumors into individual cells and re-grew them as 2D cell cultures. This destroyed the cellular environment in which a tumor exists, which contributes significantly to its response to treatment. By preserving the cancer environment in living 3D biopsies, Nolte's team is able to assess how cells respond to drugs in the relevant environment.

Full details of the work appear in the journal Biomedical Optics Express.

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