[Utility of dopamine transporter imaging (123-I Ioflupane SPECT) in the assessment of movement disorders]

Is ioflupane I123 injection diagnostically effective in patients with movement disorders and dementia? Pooled analysis of four clinical trials

OBJECTIVES

To pool clinical trials of similar design to assess overall sensitivity and specificity of ioflupane I123 injection (DaTSCAN or ioflupane ((123)I)) to detect or exclude a striatal dopaminergic deficit disorder (SDDD), such as parkinsonian syndrome and dementia with Lewy bodies.

DESIGN

Pooled analysis of three phase 3 and one phase 4 clinical trials. These four trials were selected because they were the four studies used for the US new drug application to the Food and Drug Administration (FDA).

SETTING

Multicentre, open-label, non-randomised.

PARTICIPANTS

Patients with either a movement disorder or dementia, and healthy volunteers.

INTERVENTIONS

Ioflupane ((123)I) was administered.

OUTCOME MEASURES

Images were assessed by panels of 3-5 blinded experts and/or on-site nuclear medicine physicians, classified as normal or abnormal and compared with clinical diagnosis (reference standard) to determine sensitivity and specificity.

RESULTS

Pooling the four studies, 928 participants were enrolled, 849 were dosed and 764 completed their study. Across all studies, when images were assessed by on-site readers, ioflupane ((123)I) diagnostic effectiveness had an overall (95% CI) sensitivity of 91.9% (88.7% to 94.5%) and specificity of 83.6% (78.7% to 87.9%). When reads were conducted blindly by a panel of independent experts, the overall sensitivity was 88.7% (86.8% to 90.4%) and specificity was 91.2% (89.0% to 93.0%).

CONCLUSIONS

In this pooled analysis, the visual assessment of ioflupane ((123)I) images provided high levels of sensitivity and specificity in detecting the presence/absence of an SDDD. Ioflupane ((123)I) imaging has the potential to improve diagnostic accuracy in patients with signs and symptoms of a movement disorder and/or dementia.

TRIAL REGISTRATION NUMBER

NCT00209456.

The Value of Semi-Quantitative Analysis of 123I-FP-CIT SPECT in Evaluating Patients with Parkinson's Disease

(123)I-FP-CIT SPECT binding to striatal dopamine transporter (DAT) is markedly reduced in patients with Parkinson's disease (PD) and it may also help in identifyng pre-symptomatic nigrostriatal dysfunction in subjects at risk. This study used semi-quantitative analysis of 123I-FP-CIT SPECT to evaluate the possibility of a more extensive and earlier diagnosis of dopaminergic damage. We used qualitative visual assessment and semiquantitative measures of striatal DAT binding using (123)I-FP-CIT SPECT in 154 patients with suspected PD. A control group comprised 18 people age-matched to the PD group whose follow-up disclosed essential tremor. Abnormal striatal 123I-FP-CIT uptake was evident in 134 out of 154 patients (87%). Qualitative visual assessment showed striatal dopaminergic (123)I-FP-CIT uptake was significantly reduced in 60.4% (controlateral putamen to the symptoms), in 31.3% (caudate nucleus) and in 8.3% (ipsolateral basal ganglia to the symptoms). Semi-quantitative analysis showed the following results: 32.8%, 50.7% and 16.5% respectively. We compared these two assessments and their correlation with PD clinical progression. At 24 month follow-up, patients with greater dopaminergic damage at semiquantitative analysis showed a more severe motor disability. Our findings indicate that (123)I-FP-CIT SPECT with semiquantitative analysis can offer a more accurate characterization of the dopaminergic damage in patients with suspected Parkinson's disease.