Synthesis and evaluation in primates of (N-[11C]methyl)-benperidol as a pet tracer of cerebral D2 receptor binding

The routine production of the D2 receptor-binding radioligand [11C]NMB has been optimized. Uncorrected batch yields of 62–105 mCi of [11C]NMB are obtained within 35 minutes EOB, with a specific activity exceeding 500 Ci/mmol and a radiochemical purity exceeding 95%. PET imaging of baboons shows rapid, specific localization of [11C]NMB to cerebral D2 receptor-rich tissue of primate brain. The specific localization of the radioligand is altered by drug challenge or pathological conditions, indicating utility of the ligand for human application.