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

Abstract

ObjectivesPancreatic 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 [18F]FDDNP could be used to image pancreatic islet amyloid with PET.Patients and methodsConsecutive 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 [18F]FDDNP reference compound, respectively. The pancreatic tissue sections were also incubated with [18F]FDDNP with and without its reference compound for autoradiography. Subsequently, we performed control [18F]FDDNP pancreatic PET/CT imaging in four healthy individuals. The mean standardized uptake values of [18F]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.ResultsIslet amyloid was observed in all four standard staining methods in the pancreas tissue. Similar islet amyloid distribution and phenotypes were observed clearly in the [18F]FDDNP reference compound-stained pancreas tissue. [18F]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 [18F]FDDNP uptake. The pancreas could be distinguished clearly from the liver at all-time points.ConclusionThese results suggested that [18F]FDDNP is a potential tracer for pancreatic islet amyloid PET imaging.