Evaluation of early-phase [ 18 F]-florbetaben PET acquisition in clinical routine cases

Abstract

ObjectivesIn recent years several [18F]-labelled amyloid PET tracers have been developed and have obtained clinical approval. There is accumulating evidence that early (post injection) acquisitions with these tracers are equally informative as conventional blood flow and metabolism studies for diagnosis of Alzheimer's disease, but there have been few side-by-side studies. Therefore, we investigated the performance of early acquisitions of [18F]-florbetaben (FBB) PET compared to [18F]-fluorodeoxyglucose (FDG) PET in a clinical setting.MethodsAll subjects were recruited with clinical suspicion of dementia due to neurodegenerative disease. FDG PET was undertaken by conventional methods, and amyloid PET was performed with FBB, with early recordings for the initial 10 min (early-phase FBB), and late recordings at 90–110 min p.i. (late-phase FBB). Regional SUVR with cerebellar and global mean normalization were calculated for early-phase FBB and FDG PET. Pearson correlation coefficients between FDG and early-phase FBB were calculated for predefined cortical brain regions. Furthermore, a visual interpretation of disease pattern using 3-dimensional stereotactic surface projections (3D-SSP) was performed, with assessment of intra-reader agreement.ResultsAmong a total of 33 patients (mean age 67.5 ± 11.0 years) included in the study, 18 were visually rated amyloid-positive, and 15 amyloid-negative based on late-phase FBB scans. Correlation coefficients for early-phase FBB vs. FDG scans displayed excellent agreement in all target brain regions for global mean normalization. Cerebellar normalization gave strong, but significantly lower correlations. 3D representations of early-phase FBB visually resembled the corresponding FDG PET images, irrespective of the amyloid-status of the late FBB scans.ConclusionsEarly-phase FBB acquisitions correlate on a relative quantitative and visual level with FDG PET scans, irrespective of the amyloid plaque density assessed in late FBB imaging. Thus, early-phase FBB uptake depicts a metabolism-like image, suggesting it as a valid surrogate marker for synaptic dysfunction, which could ultimately circumvent the need for additional FDG PET investigation in diagnosis of dementia.

Validation of Noninvasive Tracer Kinetic Analysis of 18F-Florbetaben PET Using a Dual–Time-Window Acquisition Protocol

“…Recent work has shown that 18 F-florbetaben PET in the early phase (0-10 min) after injection correlates visually and quantitatively with 18 F-FDG PET scans, irrespective of the amyloid plaque density assessed in late-phase 18 F-florbetaben imaging (12,13). Thus, early-phase 18 F-florbetaben uptake provides information similar to that from conventional metabolism studies, suggesting potential use as a biomarker of neuronal injury in place of an additional 18 F-FDG PET investigation (12,13). In this context, a dual-time-window acquisition protocol in which 2 short dynamic acquisitions are performed at early and late phases has been proposed as a possible alternative to long dynamic acquisitions (14).…”

Visual and Quantitative Evaluation of Amyloid Brain PET Image Synthesis with Generative Adversarial Network

“…Spatial normalization was performed on each PET image using the generated PET template [38][39][40]. Then, stochastic cerebellar masks for the PET templates were obtained from PMOD3.6 (PMOD Technologies Ltd., Zurich, Switzerland) and the Hammers brain atlas [41], and these were used to perform count normalization based on cerebellar intensity [42]. After pre-processing, the input data for the Aβ classifier was extracted and only the 15-50 th axial images so that only the axial plane that was read by the nuclear medicine physician was examined.…”

Neuro-PET – ein Update

“…Im Falle von Florbetaben erbrachte die semiquantitative Auswertung der Frühphase Korrelationskoeffizienten zum FDG-PET von bis zu 0,92 je nach Hirnregion [25]. Dieses Ergebnis war unabhängig vom zusätzlich erfassten Amyloid-Status reproduzierbar.…”