New Research: Prostrate Cancer Tumour Imaging

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 Centres 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 tumour’s production of lactate to tumour aggressiveness. Other researchers also have linked that lactate production to tumour aggressiveness and response to therapy in other cancers.

The method uses compounds involved in normal tissue function — in this case, pyruvate, which is a naturally occurring by-product of glucose, and lactate, also known as lactic acid — and uses newly developed equipment to increase the visibility of those compounds by a factor of 50,000 in a magnetic resonance imaging (MRI) scanner.

That process requires pyruvate to be prepared in a strong magnetic field at a temperature of minus 272O C, then rapidly warmed to body temperature and transferred to the patient in an MRI scanner before the polarisation decays back to its native state.

The result is a highly defined and clear image of the tumour’s outline, as well as a graph of the amount of pyruvate in the tumour and the rate at which the tumour converts the pyruvate into lactate.

The sterile production process requires a dedicated clinical pharmacist with the knowledge of both quality control and of clinical practice.

The procedure must take place within minutes, which meant integrating a clean room into the scanning facility. QB3 also worked with GE Healthcare in designing Byers Hall, in which the Surbeck Laboratory of Advanced Imaging is housed, to accommodate the extremely strong magnetic field of the MRI scanner and enable time-sensitive experiments.

“All of that insight is why we moved this technology to Northern California,” said Jonathan Murray, general manager, Metabolic Imaging at GE Healthcare. “This is a huge accomplishment UCSF and QB3 have achieved.

They brought together the best engineering from UC Berkeley and the best bioscience and pharmacy knowledge from UCSF, and are now demonstrating the technology in a world-renowned academic medical centre.

We are delighted with the speed of progress of this collaboration. The science is very exciting.”