Simplified quantification of [¹⁸F]FE-PE2I PET in Parkinson’s disease: Discriminative power, test–retest reliability and longitudinal validity during early peak and late pseudo-equilibrium

Abstract

Quantification of dopamine transporter (DAT) availability with [18F]FE-PE2I PET enables the detection of presynaptic dopamine deficiency and provides a potential progression marker for Parkinson`s disease (PD). Simplified quantification is feasible, but the time window of short acquisition protocols may have a substantial impact on the reliability of striatal binding estimates. Dynamic [18F]FE-PE2I PET data of cross-sectional (33 PD patients, 24 controls), test–retest (9 patients), and longitudinal (12 patients) cohorts were used to assess the variability and reliability of specific binding ratios (SBR) measured during early peak and late pseudo-equilibrium. Receiver operating characteristics area under the curve (PD vs. controls) was high for early (0.996) and late (0.991) SBR. Early SBR provided more favourable effect size, absolute variability, and standard error of measurement than late SBR (caudate: 1.29 vs. 1.23; 6.9% vs. 9.8%; 0.09 vs. 0.20; putamen: 1.75 vs. 1.67; 7.7% vs. 14.0%; 0.08 vs. 0.17). The annual percentage change was comparable for both time windows (−7.2%–8.5%), but decline was significant only for early SBR. Whereas early and late [18F]FE-PE2I PET acquisitions have similar discriminative power to separate PD patients and controls, the early peak equilibrium acquisition can be recommended if [18F]FE-PE2I is used to measure longitudinal changes of DAT availability.

[18F]FE-PE2I PET is a feasible alternative to [123I]FP-CIT SPECT for dopamine transporter imaging in clinically uncertain parkinsonism

“…Based on dynamic [ 18 F]FE-PE2I PET scans in PD and healthy subjects, Sonni et al [ 20 ] suggested that static imaging during early peak (17–42 min after injection) could be used as a simplified quantification method compared to the full quantification using long dynamic acquisitions. Use of 20-min static [ 18 F]FE-PE2I imaging during early peak was subsequently validated by Brumberg et al for discriminative power and for longitudinal studies in 33 PD patients and 24 healthy subjects [ 21 ].…”

Longitudinal DAT changes measured with [18F]FE-PE2I PET in patients with Parkinson’s disease; a validation study

“…To enable implementation across sites, such studies would benefit from simplified quantification methods with short acquisition protocols (e.g. 30-minute early SBR as in Brumberg et al, 2021 ). In such case, it is expected that the needed sample size would be larger than the one reported in this study.…”

“…The preliminary evaluation of an initial cohort of PD patients (n = 12) examined longitudinally with [ 18 F]FE-PE2I PET has already been reported ( Brumberg et al, 2021 ). However, a comprehensive evaluation of the performance of [ 18 F]FE-PE2I PET in measuring longitudinal DAT changes in a better-powered sample size, in sub-regions (including more versus less affected side) of the nigrostriatal system has not been reported yet.…”

Multi-Atlas MRI-Based Striatum Segmentation for 123I-FP-CIT SPECT (DAT-SPECT) Compared With the Bolt Method and SPECT-Atlas-Based Segmentation Method Toward the Accurate Diagnosis of Parkinson's Disease/Syndrome

“…18 F-FE-PE2I showed high affinity and high selectivity for DAT, faster kinetics, more favorable metbolism and low production of a radio metabolite with intermediate lipophilicity ( 13 – 15 ). Several studies have confirmed its high correlation to age even in small regions such as caudate and putamen ( r = −0.845 and −0.85, respectively) and high discriminative power between PD and healthy controls ( 16 – 19 ). Based on these previous reports, we expected that 18 F-FE-PE2I was an excellent imaging tool for in vivo DAT quantification in the entire nigrostriatal tract ( 17 , 18 , 20 ).…”