SPECT Imaging of Dopamine Transporter with [I-123] IPT in Normal Controls and Parkinson's Patients.

bjective:Dopamine transporter concentrations have been known to decrease in Parkinson’s disease(PD). The aim of the present study was to evaluate the correlation between SPECT measurements of [I-123]N-(3-iodopropene-2-yl)-2β-carbomethoxy-3β-(4-chlorophenyl) tropane(IPT) as an imaging agent for measuring changes in transporter concentrations with PD. Patients and Methods:IPT labelled with 4.87±1.29mCi(180.19±47.73 MBq) of [I-123] was intravenously injected into 23 patients(age:58±12) with PD and three normal controls(NC)(age:37±7) as bolus. Brain SPECT were then performed at 1 hour and 2 hours after injection on a double headed camera. The statistical parameters were the contrast ratio of left basal ganglia(BG) and right basal ganglia to occipital cortex(OCC) per milli curies of injected radiotracer at 1 hour and 2 hours. The correlations were evaluated between these parameters and Hoehn-Yahr classification of the patients. Results:The(BG-OCC)/OCC/mCi ratios at 1 hour and 2 hours for PD and NC were 0.14±0.07 and 0.27±0.07(1 hour) and 0.12±0.07 and 0.34±0.04(2 hour), respectively. The(BG-OCC)/OCC/mCi ratios of Parkinson’s disease were decreased with higher grade of Hoehn-Yahr classification of the patients. The ratio between BG and OCC for PD were clearly separated from NC and may be useful outcome measures for clinical diagnosis. Conclusion:The findings suggest that IPT may be a very useful tracer for early diagnosis and treatment of PD and study of dopamine re-uptake site.