Striatal Dopamine transporter in Parkinson's disease: A Study With a New Radioligand, [ 123I]B-CIT-FP

Six healthy controls and 12 patients with Parkinson's disease in different disability stages were studied with SPECT using [ 123I]-N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodo-phenyl)-nortropane ([ 123I]β-CIT-FP), a novel tracer, to label the striatal dopamine transporter. The mean uptake of [ 123I]β-CIT-FP in the putamen was reduced to 60% of the control mean and to 80% of the average control value in the caudate nucleus. In patients with totally, or predominantly unilateral symptoms the reduction was greater on the side opposite to the predominant symptoms. There was a significant negative correlation between [ 123I]β-CIT-FP uptake and the Hoehn and Yahr stage both in the putamen ( r = − 0.70, p = 0.01) and caudate nucleus ( r = - 0.81, p = 0.001). The present results show that SPECT with [ 123I]β-CIT-FP is a useful method to study the function of presynaptic dopaminergic terminals in PD. Whether [ 123I]β-CIT-FP provides advantages over widely used [ 123I]β-CIT other than a shorter scan time and a lower striatal radiation exposure remains to be seen.