1. From the Center for Cancer Research, National Cancer Institute (WDF, YL, PA, JG, SMS, DJL, MCC, SZ, AP, XY, WLD) and Departments of Nuclear Medicine (CCC) and Diagnostic Radiology (EJ), Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland, and Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center (SC), Leiden, The Netherlands