Amyloid PET imaging in multiple sclerosis: an 18F-florbetaben study

Background: Positron emission tomography (PET) images with amyloid tracers show normal uptake in healthy white matter, which suggests that amyloid tracers are potentially useful for studying such white matter diseases as multiple sclerosis (MS). Methods: Twelve patients diagnosed with MS (5 with RRMS, 5 with SPMS, and 2 with PPMS) and 3 healthy controls underwent studies with MRI and F-18-florbetaben-PET imaging. Images were preprocessed using Statistical Parametric Mapping software. We analysed F-18-florbetaben uptake in demyelinating plaques (appearing as hyperintense lesions in FLAIR sequences), in normal-appearing white matter, and in grey matter. Results: Mean standardized uptake value relative to cerebellum was higher in normally appearing white matter (NAWM) (1.51 +/- 0.12) than in damaged white matter (DWM) (1.24 +/- 0.12; P = .002). Mean percentage of change between NAWM and DWM was -17.56 % +/- 6.22 %. This percentage of change correlated negatively with EDSS scores (r = -0.61, p < .05) and with age (r = -0.83, p < 0.01). Progressive forms of MS showed a more pronounced reduction of the uptake in DWM in comparison to relapsing-remitting form. Conclusions: Uptake of 18F-florbetaben in damaged white matter is lower than that occurring in normally-appearing white matter. These findings indicate that amyloid tracers may be useful in studies of MS, although further research is needed to evaluate the utility of amyloid-PET in monitoring MS progression.