Optimization of [18F]-FDOPA Brain PET Acquisition Times for Assessment of Parkinsonism in the Clinical Setting

Graham Keir; Faizullah Mashriqi; Christopher Caravella; Sean A P Clouston; Josephine N Rini; Ana M Franceschi

doi:10.3174/ajnr.A8207

Optimization of [¹⁸F]-FDOPA Brain PET Acquisition Times for Assessment of Parkinsonism in the Clinical Setting

AJNR Am J Neuroradiol. 2024 Apr 25. doi: 10.3174/ajnr.A8207. Online ahead of print.

Authors

Graham Keir¹, Faizullah Mashriqi¹, Christopher Caravella², Sean A P Clouston³, Josephine N Rini², Ana M Franceschi⁴

Affiliations

¹ From the Neuroradiology Division (G.K., F.M., A.M.F.), Department of Radiology, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Lenox Hill Hospital, New York, New York.
² Nuclear Medicine Division (C.C., J.N.R.), Department of Radiology, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York.
³ Department of Family, Population and Preventive Medicine (S.A.P.C.), Renaissance School of Medicine at Stony Brook University, Stony Brook, New York.
⁴ From the Neuroradiology Division (G.K., F.M., A.M.F.), Department of Radiology, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Lenox Hill Hospital, New York, New York afranceschi@northwell.edu.

PMID: 38663986
DOI: 10.3174/ajnr.A8207

Abstract

Background and purpose: Fluorine 18-fluoro-L-dopa ([¹⁸F]-FDOPA) was approved by the FDA in 2019 and reimbursed by the Centers for Medicare & Medicaid Services in 2022 for use with PET to visualize dopaminergic nerve terminals in the striatum for evaluation of parkinsonism. We sought to determine the optimal image acquisition time for [¹⁸F]-FDOPA PET by evaluating rater-estimated FDOPA positivity and image quality across 4 time points.

Materials and methods: Brain PET/CT was acquired 90 minutes following injection of 185 megabecquerel (5 mCi) of [¹⁸F]-FDOPA. PET was acquired in list mode for 20 minutes, and data were replayed to represent 15-, 10-, and 5-minute acquisitions. By means of MIMneuro, PET/MR imaging or PET/CT was independently graded for FDOPA positivity and image quality by 2 readers, blinded to the clinical report and diagnosis. Expert neuroradiologist clinical reads were used as the criterion standard.

Results: Twenty patients were included, average age 65.6 years, 55% women. Image-quality ratings decreased with shorter acquisition times for both readers (reader 1, ρ = 0.23, P = .044; reader 2, ρ = 0.24, P = .036), but there was no association between abnormality confidence scores and acquisition time (reader 1, ρ = -0.13, P = .250; reader 2, ρ = -0.19, P = .100). There was a high degree of consistency in intra- and interrater agreement and agreement with the expert reads when using acquisition times of ≥10 minutes (maximal confidence score consistency [ρ = 0.92] and interrater agreement [κ = 0.90] were observed at 15 minutes), while image quality was consistently rated as low and FDOPA positivity ratings were inconsistent when using a 5-minute acquisition time.

Conclusions: Our study suggests that image-quality ratings were stable after 15 minutes and that between-subject abnormality detection rates were highly consistent between the 2 readers when acquired for at least 10 and up to 20 minutes but were inconsistent at 5 minutes. Shorter [¹⁸F]-FDOPA PET acquisition times may help maximize patient comfort while increasing throughput in the clinical setting.