[123I]Ioflupane imaging in Caucasians and non-Caucasians: Are there any differences?

Abstract

Purpose of the report: To compare diagnostic performance of [¹²³I]ioflupane SPECT imaging in different racial groups. In previous registration trials of [¹²³I]ioflupane, 99% of the subjects enrolled were Caucasians.

Materials and methods: A multicenter retrospective case-control study was conducted to evaluate whether the diagnostic performance of [¹²³I]ioflupane SPECT imaging is different in non-Caucasians than in Caucasians matched by age, sex, and final clinical diagnosis. Subjects who had received an initial diagnosis of suspected Parkinson's disease (PD) or essential tremor (ET) and then underwent [¹²³I]ioflupane SPECT imaging to assist with the subject's final clinical diagnosis were enrolled. Each subject's image was rated as normal or abnormal by 3 blinded expert readers. The majority interpretation was then compared with the final clinical diagnosis. Diagnostic performance of [¹²³I]ioflupane SPECT imaging (as measured by positive percent agreement (equivalent to sensitivity), negative percent agreement (equivalent to specificity), overall percent agreement (OPA), and measures of inter-rater agreement) were compared between the Caucasian and non-Caucasian groups.

Results: In total, 102 non-Caucasians (58 with PD and 44 with ET as a final clinical diagnosis) and 102 Caucasians (58 with PD, 43 with ET, and 1 with "other") were included in the intent-to-diagnose (ITD) population. There was no significant difference between Caucasians and non-Caucasians in the diagnostic performance of [¹²³I]ioflupane SPECT imaging as measured by sensitivity, specificity, OPA, and measures of inter-rater agreement.

Conclusion: In this study, the diagnostic performance of [¹²³I]ioflupane SPECT imaging was comparable between Caucasians and non-Caucasians.

Keywords: Caucasian; DaTSCAN; Essential tremor; Non-Caucasian; Parkinson's disease.