Binding of [99mTc]TRODAT-1 to dopamine transporters in patients with Parkinson's disease and in healthy volunteers.

[@Tc]TRODAT-1is a radiolabeiedtropanethat bindsdopamine transporters. The primary goal of this study was to determine whetherIts regionalcerebraldistributioncould differentiatebe tweenpatientswith Parkinson's diseaseand healthyhuman volunteers.Methods: The sampleconsistedof 42 patientswith Parkinson's disease, 23 age-matched controls, and 38 heaithy adults youngerthan 40 y old. SPECTscansof the brain were acquiredon a triple-head-,tcamera3—4 h afterthe intravenous injectionof 740 MBq (20 mCi) (@‘Tc]TRODAT-1 . Meancounts per pixel were measuredmanuallyin subregionsof the basal gangliaand normalizedto the meanbackgroundcountsto give specificuptakevalues([SUVs]=k3/k4).Patientand control groups werealsocompared withautomated statistical parametric mappingtechniques.Logisticdiscriminantanalyseswere per formed todetermine theoptimum uptake valuesfor differentiating patients from age-matched controls. Results: Quantitative im ageanalysisshowedthatthe groupmeanSUVsin patientswere less than the mean values in controls for all regions (all P@ < 0.000001). Therewasoverlapinthecaudate aswellasin the anterior-mostportionof the putamen,but notin the posterior putamen,evenwhenthe asymptomaticsidesof 5 patientswith clinically defined hemi-Parkinson's disease were factored in. Conclusion: Thefindings indicate thatParkinson's disease can bedetectedwith[@Tc]TRODAT bysimplyinspectingtheimages for uptake in the posteriorputamen.Appropriateasymmetries seem to be visible with quantificationin patientswith clinically defined hemi-Parkinson's disease, even though changes in the putamencontralateralto the clinicallyunaffectedside in these patientsappearto precedethedevelopment of symptoms.