New prostate cancer imaging shows real-time tumor metabolism

A UCSF research collaboration with GE Healthcare has produced the first results in humans of a new technology that promises to rapidly assess the presence and aggressiveness of prostate tumors in real time, by imaging the tumor's metabolism.

This is the first time researchers have used this technology to conduct real-time metabolic imaging in a human patient and represents a revolutionary approach to assessing the precise outlines of a tumor, its response to treatment and how quickly it is growing.

Data on the first four patients will be presented on Dec. 2 at the Radiology Society of North America's weeklong annual conference.

The initial results validate extensive preclinical research that has linked the speed at which tumors metabolize nutrients to the aggressiveness of their growth. The new imaging technique also has been used to show early biochemical changes in animal tumors in real time as they respond to medication therapy, long before a physical change occurs.

So far, the technology has produced the same response in human patients' tumors as it did in laboratory studies, even at the lowest dose, according to Sarah Nelson, PhD, a professor of Radiology and Biomedical Imaging and a member of the California Institute for Quantitative Biosciences (QB3) at UCSF.

"This is a key milestone that could dramatically change clinical treatment for prostate cancer and many other tumors," Nelson said. "We had shown this worked in animal models and tissues samples. Now, in men, we are seeing exactly the type of results we had hoped for."

For an oncologist, that means immediate feedback on whether a patient's therapy is working, either during standard treatment or in a clinical trial.

"If we can see whether a therapy is effective in real time, we may be able to make early changes in that treatment that could have a very real impact on a patient's outcome and quality of life," said Andrea Harzstark, MD, an oncologist with the UCSF Helen Diller Family Comprehensive Cancer Center who is leading the clinical aspects of the current study.

More than 200,000 men are diagnosed with prostate cancer each year and 28,000 die from it, making it one of the most common cancer in men nationwide and also one of the leading causes of cancer death in men, according to the Centers for Disease Control.

Yet the disease ranges widely in its rate of growth and aggressiveness, according to John Kurhanewicz, PhD, a UCSF expert in prostate cancer imaging. As a result, there is great debate over the ideal strategy for treating the disease, he said, leaving patients with a difficult and potentially life-changing decision over how aggressively to respond to the disease.

"This test could give both physicians and patients the information they need to make that decision," said Kurhanewicz, whose work with Dan Vigneron, PhD, and their colleagues from the UCSF Department of Radiology and Biomedical Imaging first linked a prostate tumor's production of lactate to tumor aggressiveness. Other researchers also have linked that lactate production to tumor aggressiveness and response to therapy in other cancers.