Noninvasive imaging system predicts breast cancer patients’ response to chemo

An optical imaging technique developed at Columbia University could predict neoadjuvant chemotherapy outcomes in breast cancer patients as early as two weeks after beginning treatment, researchers reported this week in Radiology.

The study, co-led by Andreas H. Hielscher, PhD, focused on integrating a noninvasive, light-based system for measuring blood flow dynamics into breast cancer patients’ care routines. And though the tech behind Hielscher et al.’s method may be complex, the mode of measurement isn’t—the researchers were able to collect all necessary data from one 15-second breath hold.

“There is currently no method that can predict treatment outcome of chemotherapy early on in treatment, so this is a major advance,” Hielscher said in a release from Columbia. “X-ray imaging uses damaging radiation and so is not well-suited for treatment monitoring, which requires imaging sessions every two to three weeks. MRIs are expensive and take a long time, from 30 to 90 minutes, to perform.”

His team’s system, he said, uses harmless light, can be performed more frequently than an MRI and takes less than 10 minutes to complete.

Hielscher and colleagues analyzed imaging data from 34 invasive breast cancer patients, all of whom were treated between June 2011 and March 2016. Participants positioned their breasts in the optical system—which doesn’t use compression like a mammography—and the tomographic system went to work generating 3D images of both breasts simultaneously.

The method also allowed the researchers to study vasculature and blood flow patterns in the breasts, according to the study, so they were able to observe how a patient’s blood interacted with her tumor. All participants were asked to hold their breath for 15 seconds during the imaging scan, which inhibited backflow of blood through veins in the breast but not the inflow through the arteries.

“This helps us distinguish malignant from healthy tissue and tells us how the tumor is responding to chemotherapy earlier than other imaging techniques can,” Hielscher said.

Neoadjuvant chemotherapy is the typical treatment path for a woman diagnosed with invasive, but operable, breast cancer. Its goal, the authors wrote, is to shrink tumors prior to any surgical intervention. In some cases, the therapy converts inoperable cancers into operable ones, or downgrades a mastectomy to breast-conserving therapy. When neoadjuvant chemo patients achieve a complete response to the therapy, their risk of cancer recurrence is lowered—but less than half of women get to that point.

“Patients who respond to neoadjuvant chemotherapy have better outcomes than those who do not, so determining early in treatment who is going to be more likely to have a complete response is important,” co-study leader Dawn Hershman, MD, said in the Columbia release. “If we know early that a patient is not going to respond to the treatment they are getting, it may be possible to change treatment and avoid side effects.”

Hielscher’s team used the optical system on women before treatment and two weeks into chemotherapy, eventually comparing those images to the patients’ five-month results. Rates of blood inflow and outflow distinguished whether treatment was effective or ineffective in patients, the authors reported.

“If we can confirm these results in the larger study that we are planning to begin soon, this imaging system may allow us to personalize breast cancer treatment and offer the treatment that is most likely to benefit individual patients,” Hershman said.