[I-123]FP-CIT SPECT is a useful method to monitor the rate of dopaminergicdegeneration in early-stage Parkinson's disease

We investigated the applicability [I-123]FP-CIT SPECT for the assessment of the rate of dopaminergic degeneration in PD. Twenty early-stage PD patients (age range 43-73 yr; mean age 55.4) were exa mined twice, a mean of 12 months apart. The mean annual change in the ratio of specific to nonspecific [I-123]FP-CIT binding to the striatum was used as the outcome measure. The mean annual decrease in striatal [I-123]FP-CIT binding ratios was found to be about 8% (of the baseline mean). In order to demonstrate a significant effect (p < 0.05) of putative neuropr otective agent with 0.80 power and 50% of predicted protection within 2 yea rs, 36 patients are required in each group, when the effects are measured b y means of changes in [I-123]FP-CIT binding ratios in whole striatum. Our findings indicate that [I-123]FP-CIT SPECT seems to be a useful tool to investigate the progression of dopaminergic degeneration in PD and may pro vide an objective method of measuring the effectiveness of neuroprotective therapies.