Barrow Scientist Awarded NIH Grants to Improve Imaging for Brain Tumors
Barrow researcher Chad Quarles, PhD, and his team have received two R01 grants from the National Institutes of Health to develop advanced imaging methods for brain cancer, specifically glioblastoma. Among adults, glioblastoma is the deadliest and most common of the tumors that originate in the brain.
The grants provide more than $2 million over five years, allowing the team to research safe, affordable, and accurate imaging methods that are specifically sensitive to the unique biology of glioblastoma and other brain tumors.
Dr. Quarles said that although there have been advancements in therapeutic options for people with brain tumors, standard clinical imaging methods are unable to reliably and efficiently show whether a tumor is responding to therapy or continuing to grow. This forces clinicians to take a “wait and see” approach before considering changes to a person’s treatment.
“We want to leverage advances in imaging technology to develop targeted bioimaging methods that are specifically sensitive to a tumor’s underlying cellular, molecular, and metabolic features,” Dr. Quarles explained.
He said next-generation imaging methods could not only enable physicians to evaluate treatment response early on, but these methods could also better characterize tumors, define their margins, and predict where they will recur. These improvements could help physicians to select patient-specific therapeutic strategies that are tailored to a tumor’s unique biological signature.
Currently, contrast-enhanced MRI (CE-MRI) is the primary means to detect new and recurrent brain tumors, as well as to assess therapeutic response. However, this type of imaging cannot delineate between tumor types and is confounded by treatment effects.
“Contrast enhancement can occur where there’s tumor recurrence, but it can also occur as a consequence of radiation therapy,” Dr. Quarles said. “If we scan a patient every two to three months, it may take six months to figure out if that new enhancement originates from radiation effects or tumor recurrence. With these new imaging methods, we might be able to pick up on these changes over the course of weeks.”
Dr. Quarles said dynamic susceptibility contrast MRI (DSC-MRI) has been one of the most reliable methods for making this distinction in contrast enhancement because it can show changes in blood volume. To grow, cancerous tumor cells rely on the formation of new blood vessels — a process called angiogenesis.
He and his team believe advanced DSC-MRI could overcome the limitations of standard imaging and potentially impact radiographic diagnosis, response assessment, and image-guided biopsies.
Dr. Quarles and his team have developed and validated new DSC-MRI techniques for brain tumor imaging and are now working to optimize and validate the use of these techniques in a clinical setting.
We want to leverage advances in imaging technology to develop targeted bioimaging methods that are specifically sensitive to a tumor’s underlying cellular, molecular, and metabolic features.
-Dr. Chad Quarles, Associate Professor, Imaging Research
“The way we validate these methods in patients is by using image-guided biopsies,” he said. “We specifically recruit patients who are going to have brain tumor surgery and add on our scan before their surgery. The neurosurgeons mark specifically in the imaging space where the tumor samples came from so that we can spatially align those samples to our advanced imaging data.”
Dr. Quarles said the willingness of the neurosurgeons and neuroradiologists to work with scientists was one of the reasons he brought his research to Barrow in August 2015.
“You have to demonstrate that the imaging methods you develop have the sensitivity and specificity that’s necessary for making clinical decisions, but then to get it into actual clinical use you have to have clinicians who are willing to try new methods,” he said.
While brain tumors are the main focus of the R01 grants, Dr. Quarles said his lab has also received funding to apply bioimaging methods in people with Alzheimer’s disease and amyotrophic lateral sclerosis (ALS).