Dr. Choyke on Differences Between PET Scans in Prostate Cancer

Peter L. Choyke, MD, FACP, director, Molecular Imaging Program, head, Imaging Section, Center for Cancer Research, National Cancer Institute (NCI), discusses the differences between PET scans in prostate cancer.

When conducing imaging on a patient with prostate cancer, there are 2 typical choices of PET scans—prostate-specific membrane antigen (PMSA) and sodium fluoride PET scans. Choyke says that through a comparative investigation done at NCI, they found that these 2 PET scans do not match up with each other. Early on in the disease course, the imaging from each of these PET scans matches up, but as the disease progresses, they match less, he explains.

Choyke says that this is important because some treatments such as radium-223 dichloride (Xofigo) are very dependent on the bone turnovers, which is reflected in the sodium fluoride PET scan. PSMA-PET, which indicates where the active disease is, does not overlap with the sodium fluoride PET scan, says Choyke. This means that there is a chance that giving radium-223 will do nothing to the cancer. Choyke says that there is work being done to better select patients for radium-223 so that the right patients get the right treatment.