A pilot study of pancreatic islet amyloid PET imaging with [(18)F]FDDNP

OBJECTIVES: Pancreatic islet amyloid deposition occurs before β-cell damage in type 2 diabetes mellitus patients. The islet and Alzheimer’s disease β-amyloid shares similar secondary structures. The Alzheimer’s disease β-amyloid targeting tracer [(18)F]FDDNP could be used to image pancreatic islet amyloid with PET. PATIENTS AND METHODS: Consecutive pancreatic tissue sections from a 69-year-old male type 2 diabetes mellitus patient were stained by hematoxylin and eosin, anti-amylin antibody, Congo Red, periodic acid-Schiff, and [(18)F]FDDNP reference compound, respectively. The pancreatic tissue sections were also incubated with [(18)F]FDDNP with and without its reference compound for autoradiography. Subsequently, we performed control [(18)F]FDDNP pancreatic PET/CT imaging in four healthy individuals. The mean standardized uptake values of [(18)F]FDDNP uptake in the pancreatic head, neck, body, and tail, blood pool, liver, and vertebral bone from 5 to 120 min after injection were determined. RESULTS: Islet amyloid was observed in all four standard staining methods in the pancreas tissue. Similar islet amyloid distribution and phenotypes were observed clearly in the [(18)F]FDDNP reference compound-stained pancreas tissue. [(18)F]FDDNP was intensively accumulated in the same pancreatic tissue in autoradiography, which was largely blocked by its reference compound. In the PET/CT scans of control human participants, the mean standardized uptake values in pancreas decreased to the blood pool level in 30 min and all parts of the pancreas had similar [(18)F]FDDNP uptake. The pancreas could be distinguished clearly from the liver at all-time points. CONCLUSION: These results suggested that [(18)F]FDDNP is a potential tracer for pancreatic islet amyloid PET imaging.