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

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 [F]FDDNP could be used to image pancreatic islet amyloid with PET.

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 [F]FDDNP reference compound, respectively. The pancreatic tissue sections were also incubated with [F]FDDNP with and without its reference compound for autoradiography. Subsequently, we performed control [F]FDDNP pancreatic PET/CT imaging in four healthy individuals. The mean standardized uptake values of [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.

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 [F]FDDNP reference compound-stained pancreas tissue. [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 [F]FDDNP uptake. The pancreas could be distinguished clearly from the liver at all-time points.

These results suggested that [F]FDDNP is a potential tracer for pancreatic islet amyloid PET imaging.