Optoacoustic Imaging Reveals Scope of Pancreatic Cancer at Early Stage

A new imaging technique could improve survival rates for pancreatic cancer by enabling physicians to detect the full extent of the disease for surgical intervention. The technique pairs a contrast agent with multispectral optoacoustic tomography (MSOT) to identify pancreatic cancer cells at the microscopic level, at ~10× more magnitude than what is currently possible.

A research project led by Lacey McNally and Ajay Jain, MD, professors of surgery at the University of Oklahoma’s OU College of Medicine will investigate the technique's efficacy in evaluating the spread of pancreatic cancer. McNally and Jain received a $3 million grant from the National Cancer Institute of the National Institutes of Health to fund the project.

“Pancreatic cancer is one of the hardest cancers to cure because it is difficult to detect cancer cells at the microscopic level,” Jain said. “Because there are usually no early symptoms of pancreatic cancer, it is typically not diagnosed until after it has spread, and outcomes are very poor — about a 9% overall chance of survival.”

Current imaging options for pancreatic cancer, like computed tomography (CT), can only detect the cancer when it has grown to about 1 cm in size.

The new imaging approach is expected to address gaps in imaging by detecting cancerous cells at the 200-μm level. The technique employs a contrast agent developed by McNally's lab. The contrast agent, administered intravenously, is designed to differentiate pancreatic cancer from other cells based on the cell’s environment. Because the contrast agent is activated by acidity, it's able to distinguish pancreatic cancer, which has an acidic environment, from other cells.

The other component, the MSOT imaging device, works in tandem by delivering infrared (IR) light to the patient. The IR radiation excites the dye of the contrast agent, creating sound waves that MSOT captures and converts to colors. The resulting image provides enough detail to identify cancer cells that would otherwise go undetected.

“This is a hybrid approach that accomplishes what a CT cannot,” McNally said. “Pancreatic cancer often creates tentacles that spread out beyond the primary tumor. Currently, there is no way for the surgeon to know where they are."

MSOT has the potential to inform a surgical team in real time where the cancer has metastasized, allowing them to remove it.

“Surgery and chemotherapy offer the patients the best chance, but for surgery to work, we have to remove all the cancer, and that is difficult to do,” Jain said. “This approach, at a very microscopic level, appears able to inform us whether we are getting all the cancer.”

If successful, the imaging technique could inform treatment plans. If, for example, MSOT shows that the cancer has invaded the two critical blood vessels that hug the head of the pancreas, surgeons could plan accordingly. If chemotherapy is given ahead of surgery, imaging could show whether cancerous cells on the blood vessels have been eradicated or if cancer is still present.

Ultimately, the new imaging approach could be used as a screening tool in patients who face a high risk of pancreatic cancer, such as those with a family history or a genetic predisposition for the disease.

“Early detection of pancreatic cancer offers the best chance of a cure,” Jain said. “If we could detect the cancer at an early, microscopic stage, it could be curable.”

The funding supports continued tests of the imaging by McNally and Jain. McNally is currently testing the imaging approach in several other clinical trials at OU Health Sciences, including a recently completed study in breast cancer.

“This type of research collaboration between a translational scientist and a surgeon is extremely unusual,” McNally said. “We have the opportunity to improve a surgical technique. The scientific and medical communities have made great strides in treating some types of cancer, but pancreatic cancer patients have the poorest survival. The outcome of this research could fundamentally change people’s lives.”

The University of Oklahoma and Georgia State University jointly own pending patent applications on contrast agents and the use of the MSOT device with contrast agents.