title: The effect of levodopa therapy on dopamine transporter SPECT imaging with( 123)I-FP-CIT in patients with Parkinson's disease.
abstract: OBJECTIVE
  The aim of this study was to evaluate, by means of (123)I-FP-CIT SPECT, the effect of chronic treatment with levodopa on striatal dopamine transporter (DAT) in patients with Parkinson's disease.
  
  
  METHODS
  Fifteen patients under stable levodopa/carbidopa monotherapy were imaged twice: at baseline on medication and after at least 20 days of treatment wash-out. DAT levels were assessed from SPECT imaging for the entire striatum, the right and left striatum, the right and left putamen and the right and left caudate, as a ratio of regional brain activities using the formula: (striatal region of interest-occipital)/occipital.
  
  
  RESULTS
  During levodopa wash-out, despite a worsening in patients' clinical disability (H&Y mean stage 2.53+/-0.58 versus 1.73+/-0.45 on therapy, p<0.001), striatal( 123)I-FP-CIT levels were not significantly different from those at baseline in any of the brain regions examined.
  
  
  CONCLUSIONS
  The results of this study suggest that levodopa does not affect( 123)I-FP-CIT brain imaging and confirm that it is not necessary to withdraw this medication to measure DAT levels with SPECT.
authors.affiliation: Department of Biopathology and Diagnostic Imaging, University Tor Vergata, Rome, Italy. oschil@tiscalinet.it
authors.forename: Orazio
authors.initials: O
authors.lastname: Schillaci
authors.forename: Mariangela
authors.initials: M
authors.lastname: Pierantozzi
authors.forename: Luca
authors.initials: L
authors.lastname: Filippi
authors.forename: Carlo
authors.initials: C
authors.lastname: Manni
authors.forename: Livia
authors.initials: L
authors.lastname: Brusa
authors.forename: Roberta
authors.initials: R
authors.lastname: Danieli
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bernardi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Simonetti
authors.forename: Paolo
authors.initials: P
authors.lastname: Stanzione
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage; D016477:Artifacts; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007980:Levodopa / Q000008:administration & dosage*; D008297:Male; D008657:Metabolic Clearance Rate / Q000187:drug effects; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014326:Tropanes / Q000493:pharmacokinetics
chemical_list: D000978:Antiparkinson Agents; D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D007980:Levodopa