Groundbreaking New Technology Uses Sugar to Diagnose & Assess Prostate Tumors

The following was written by Sarah J. Nelson,PhD, Director of the Surbeck Laboratory of Advanced Imaging, and Margaret Hart Surbeck Distinguished Professor in the Department of Radiology and Biomedical Imaging

New imaging technology developed at UCSF in collaboration with GE Healthcare will rely on a natural compound to noninvasively and precisely image tumors and see if cancer medication is working effectively. The procedure uses a compound called pyruvate, which is created when glucose breaks down in the body. In cancers the pyruvate is preferentially converted to lactate, which can be detected using specialized magnetic resonance imaging (MRI) methods. Pre-clinical studies have shown that the rate of conversion and amount of lactate produced enables precise detection of a tumor, identification of which cancers are most aggressive and the ability to track early biochemical changes as tumors respond to medication.

A recent publication describes the first in-man study that has been performed at UCSF using this technology. The results have shown that it is safe in humans and that it effectively detects tumors in patients with prostate cancer. This lays the groundwork for the use of this technology to diagnose a variety of cancers and to track treatment noninvasively, without repeated biopsies.

Prostate cancer is the most common form of cancer, with more than 200,000 new cases reported each year in the United States. The increased use of prostate-specific antigen (PSA) levels for screening men has been widely recognized as having identified more patients with prostate cancer at an earlier, and potentially more treatable, stage. Many of those tumors are slow growing, but it is difficult to predict which those are. For an oncologist, this real-time imaging could provide immediate feedback on whether a patient should continue active surveillance of the tumor or pursue treatment, and also whether a therapy is working, either during standard treatment or in a clinical trial.

In this clinical research study, which started in December 2010, the researchers labeled pyruvate with carbon-13, processed the compound using dynamic nuclear polarization and injected this “hyperpolarized pyruvate” into 31 patients with prostate cancer, who were recruited in the UCSF Medical Center and UCSF Helen Diller Family Comprehensive Cancer Center. The team used MR methods to follow the delivery of pyruvate and its conversion to lactate in the prostate. The higher, more intense signals indicated a more rapid conversion to lactate, possibly a sign of more aggressive cancer. Conversely, normal prostates resulted in very limited conversion. This study focused on patients with relatively low-grade prostate tumors who had not yet received treatment, as to identify the safe and appropriate dosage of pyruvate needed. Future studies will use this technology to access the effectiveness of a patient’s therapy in shrinking their tumor.

For more information this study, please see the full article in Science Translational Medicine.

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