Comprehensive evaluation of early-phase FP-CIT PET as a substitute for brain FDG PET in parkinsonism.

BACKGROUND

Early-phase F-18 FP-CIT PET/CT (PETFP-CIT) has been reported to possibly replace FDG PET/CT (PETFDG) in the differential diagnosis of parkinsonism. We investigated the correlation between PETFP-CIT and PETFDG to explore their potential interchangeability.

METHOD: Our retrospective study included 187 participants, categorized into Parkinson's disease (PD), atypical parkinsonian disorders (APD), and participants with intact dopamine transporters (DATintact). We analyzed the correlation of standardized uptake value ratios (SUVR) from early-phase PETFP-CIT and PETFDG scans across 23 different brain volumes-of-interest using Pearson's correlation analysis. We conducted this analysis for all participants collectively and then separately for each group.

RESULTS

For all participants without grouping, a moderate correlation (with correlation coefficients R ranging from 0.360 in right putamen to 0.530 in left caudate nucleus) was observed between Early-phase PETFP-CIT and PETFDG. PD group showed a weak to moderate correlation (0.226 in left frontal cortex ≤ R ≤ 0.555 in right cerebellum). APD group revealed a moderate correlation with R ranging from 0.488 in right cerebellum to 0.692 in right occipital cortex. Conversely, a lack of correlation in specific areas for DATintact group indicated distinctions between the modalities.

CONCLUSIONS

Our study showed interchangeability with a moderate correlation between early-phase PETFP-CIT and PETFDG. However, careful consideration is needed for DATintact group.