J Nucl Med 2001 Sep;42(9):1303-8
Evaluation of early-stage Parkinson's disease with 99mTc-TRODAT-1 imaging.
Huang WS, Lin SZ, Lin JC, Wey SP, Ting G, Liu RS.
Parkinson's disease is a progressive neurodegenerative disorder characterized by
a selective loss of dopamine in the striatum. Problems remain in the accurate
diagnosis of Parkinson's disease. A 99mTc-labeled tropane derivative that binds
to dopamine transporter with high selectivity is
[2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]ethanethiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)]
(TRODAT-1). The purpose of this study was to investigate the potential
usefulness of 99mTc-TRODAT-1 imaging in the evaluation of patients with
early-stage Parkinson's disease. METHODS: Thirty-four patients with early-stage
idiopathic Parkinson's disease were recruited. For all patients, the Parkinson's
disease was stage 2 or less as assessed by the Hoehn and Yahr scale. Seventeen
age-matched healthy volunteers (8 men, 9 women) served as controls.
99mTc-TRODAT-1 was prepared from a lyophilized kit. Brain SPECT imaging was
performed between 165 and 195 min after injection, using a double-head camera
equipped with fanbeam collimators. Specific uptake in the striatum and its
subregions, including the putamen and caudate nucleus, was calculated and
compared with that of the other sides and of healthy volunteers. RESULTS: A
continuous reduction in specific striatal uptake of 99mTc-TRODAT-1 with
increasing disease severity was found in Parkinson's disease patients (control
vs. stage I vs. stage II, 1.98 vs. 1.62 vs. 1.22, respectively, P < 0.01).
The changes were magnified by measurement of specific putaminal uptake (control
vs. stage I vs. stage II, 1.81 vs. 1.27 vs. 0.94, respectively, P < 0.01).
The mean values of specific putaminal uptake contralateral to the more affected
limbs were significantly decreased compared with the ipsilateral sides in both
stage I and stage II groups (1.02 vs. 1.49 for stage I and 0.73 vs. 1.14 for
stage II, P < 0.01). Moreover, a significant loss of putaminal uptake
ipsilateral to the symptoms was found in the stage I group compared with the
healthy volunteers (1.49 vs. 1.81, P < 0.01). The difference became greater
when the posterior putaminal uptakes were compared. No remarkable adverse
reactions were found in either healthy volunteers or Parkinson's disease
patients during or after imaging. CONCLUSION: For clinical practice,
99mTc-TRODAT-1 may serve as a useful imaging agent for the early detection of
Parkinson's disease.
