title: Evaluation of an optimized [18F]fluoro-deoxy-glucose positron emission tomography voxel-wise method to early support differential diagnosis in atypical Parkinsonian disorders.
abstract: Atypical Parkinsonian disorders (APD) frequently overlap in clinical presentations, making the differential diagnosis challenging in the early stages. The present study aimed to evaluate the accuracy of the [18F]fluoro-deoxy-glucose positron emission tomography Statistical Parametric Mapping (SPM) optimized procedure in supporting the early and differential diagnosis of APD.
  
  
  
  Seventy patients with possible APD were retrospectively included from a large clinical cohort. The included patients underwent [18F]fluoro-deoxy-glucose positron emission tomography within 3 months of the first clinical assessment and a diagnostic follow-up. An optimized SPM voxel-wise procedure was used to produce t-maps of brain hypometabolism in single subjects, which were classified by experts blinded to any clinical information. We compared the accuracy of both the first clinical diagnosis and the SPM t-map classifications with the diagnosis at follow-up as the reference standard.
  
  
  
  At first diagnosis, 60% of patients were classified as possible APD (progressive supranuclear palsy, corticobasal degeneration, dementia with Lewy bodies, multiple system atrophy) and about 40% as APD with uncertain diagnosis, providing 52% sensitivity, 97% specificity and 86% accuracy with respect to the reference standard. SPM t-map classification showed 98% sensitivity, 99% specificity and 99% accuracy, and a significant agreement with the diagnosis at follow-up (P < 0.001).
  
  
  
  The SPM t-map classification at entry predicted the second diagnosis at follow-up. This indicates its significantly superior role for an early identification of APD subtypes, particularly in cases of uncertain diagnosis. The use of a metabolic biomarker at entry in the instrumental work-up of APD may shorten the diagnostic time, producing benefits for treatment options and support to the patients.
authors.affiliation: Vita-Salute San Raffaele University, Milan, Italy.|Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: S P
authors.initials: SP
authors.lastname: Caminiti
authors.affiliation: Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Alongi
authors.affiliation: Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Majno
authors.affiliation: Department of Neurology, San Raffaele Hospital, Milan, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Volontè
authors.affiliation: Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.|Neurological Rehabilitation Department, San Raffaele Hospital, Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cerami
authors.affiliation: Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Gianolli
authors.affiliation: Department of Neurology, San Raffaele Hospital, Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Comi
authors.affiliation: Vita-Salute San Raffaele University, Milan, Italy.|Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.|Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Perani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001480:Basal Ganglia Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging* / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Statistical Parametric Mapping; biomarkers; corticobasal degeneration; dementia with Lewy bodies; hypometabolism; multiple system atrophy; progressive supranuclear palsy; single subject