Patlak plot based on the first 30 minutes post-injection dynamic 18F-florbetaben positron emission tomography scan separates amyloid-β positive from negative studies

Abstract

Objective: This work aims to search for the shortest duration of an early 18F-florbetaben positron emission tomography (PET) dynamic acquisition to obtain reliable information on the brain amyloid-β (Aβ) deposition and perfusion. Methods: 25 patients that underwent an early 18F-florbetaben PET dynamic acquisition starting immediately post-injection (maximum of 60 min duration) were retrospectively included. Reference region-based Patlak plot [Formula: see text] (transference rate to the irreversible compartment) and [Formula: see text] (distribution volume) were computed. Shorter early dynamic acquisitions were simulated to a minimum of 15 min duration. Three nuclear medicine physicians evaluated qualitatively the [Formula: see text] parametric images obtained in comparison with those obtained from the standard clinical protocol defined by a late acquisition of 20 min duration starting 90 min post-injection. Results: All the [Formula: see text] parametric images obtained with at least an early 30-min dynamic acquisitions were suitable for visual classification. Shorter early acquisitions originated images with too much noise, making qualitative assessment difficult. Aβ deposition visual classification based on the [Formula: see text] images were highly concordant with the evaluation of standard late acquisitions (readers consensus agreement of 92%). [Formula: see text] images obtained from the different early dynamic acquisition’s duration were visually indistinguishable from each other (voxelwise r ≥ 0.98). Conclusion: Patlak plot method applied to early 30-min 18F-florbetaben PET dynamic acquisition may be an alternative to the dual acquisition protocol sometimes used in clinics. This improves patients’ comfort, service logistics and reduces radiation exposure. Advances in knowledge: This work shows, for the first time, that early (0–30 min post-injection) 18F-florbetaben dynamic PET scans with reference region-based Patlak plot method could replace the dual acquisition protocol and the 90–110 min standard acquisition.