title: Impact of molecular imaging on the diagnostic process in a memory clinic.
abstract: BACKGROUND
  [(11)C]Pittsburgh compound B ([(11)C]PIB) and [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]FDG) PET measure fibrillar amyloid-β load and glucose metabolism, respectively. We evaluated the impact of these tracers on the diagnostic process in a memory clinic population.
  
  
  METHODS
  One hundred fifty-four patients underwent paired dynamic [(11)C]PIB and static [(18)F]FDG PET scans shortly after completing a standard dementia screening. Two-year clinical follow-up data were available for 39 patients. Parametric PET images were assessed visually and results were reported to the neurologists responsible for the initial diagnosis. Outcome measures were (change in) clinical diagnosis and confidence in that diagnosis before and after disclosing PET results.
  
  
  RESULTS
  [(11)C]PIB scans were positive in 40 of 66 (61%) patients with a clinical diagnosis of Alzheimer's disease (AD), 5 of 18 (28%) patients with frontotemporal dementia (FTD), 4 of 5 (80%) patients with Lewy body dementia, and 3 of 10 (30%) patients with other dementias. [(18)F]FDG uptake patterns matched the clinical diagnosis in 38 of 66 (58%) of AD patients, and in 6 of 18 (33%) FTD patients. PET results led to a change in diagnosis in 35 (23%) patients. This only occurred when prior diagnostic certainty was <90%. Diagnostic confidence increased from 71 ± 17% before to 87 ± 16% after PET (p < .001). Two-year clinical follow-up (n = 39) showed that [(11)C]PIB and [(18)F]FDG predicted progression to AD for patients with mild cognitive impairment, and that the diagnosis of dementia established after PET remained unchanged in 96% of patients.
  
  
  CONCLUSIONS
  In a memory clinic setting, combined [(11)C]PIB and [(18)F]FDG PET are of additional value on top of the standard diagnostic work-up, especially when prior diagnostic confidence is low.
authors.affiliation: Department of Neurology and Alzheimer Center, VU University Medical Center, Amsterdam, The Netherlands. r.ossenkoppele@vumc.nl
authors.forename: Rik
authors.initials: R
authors.lastname: Ossenkoppele
authors.forename: Niels D
authors.initials: ND
authors.lastname: Prins
authors.forename: Yolande A L
authors.initials: YA
authors.lastname: Pijnenburg
authors.forename: Afina W
authors.initials: AW
authors.lastname: Lemstra
authors.forename: Wiesje M
authors.initials: WM
authors.lastname: van der Flier
authors.forename: Sofie F
authors.initials: SF
authors.lastname: Adriaanse
authors.forename: Albert D
authors.initials: AD
authors.lastname: Windhorst
authors.forename: Ron L H
authors.initials: RL
authors.lastname: Handels
authors.forename: Claire A G
authors.initials: CA
authors.lastname: Wolfs
authors.forename: Pauline
authors.initials: P
authors.lastname: Aalten
authors.forename: Frans R J
authors.initials: FR
authors.lastname: Verhey
authors.forename: Marcel M
authors.initials: MM
authors.lastname: Verbeek
authors.forename: Mark A
authors.initials: MA
authors.lastname: van Buchem
authors.forename: Otto S
authors.initials: OS
authors.lastname: Hoekstra
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: Philip
authors.initials: P
authors.lastname: Scheltens
authors.forename: Bart N M
authors.initials: BN
authors.lastname: van Berckel
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000523:psychology; D000814:Aniline Compounds; D001921:Brain / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes; D003704:Dementia / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000523:psychology; D003937:Diagnosis, Differential; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D005602:France; D057180:Frontotemporal Dementia / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000523:psychology; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000523:psychology; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging* / Q000209:etiology; D008875:Middle Aged; D057054:Molecular Imaging; D010044:Outpatient Clinics, Hospital / Q000706:statistics & numerical data; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013844:Thiazoles; D016896:Treatment Outcome
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000814:Aniline Compounds; D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D013844:Thiazoles; D019788:Fluorodeoxyglucose F18