Diagnostic Value of ¹²³I-Ioflupane and ¹²³I-Iodobenzamide SPECT Scans in 248 Patients with Parkinsonian Syndromes

Abstract

Background: SPECT is one of the most employed techniques in the diagnostic workup of idiopathic Parkinson’s disease (IPD). Despite its widespread use, the exact diagnostic accuracy of this technique in parkinsonian syndromes remains controversial. Methods: In this study, we investigated the diagnostic accuracy of an initial ¹²³I-ioflupane (FP-CIT) and/or ¹²³I-iodobenzamide (IBZM) SPECT to differentiate between IPD and other parkinsonian disorders. 248 patients underwent a SPECT scan because of an as yet unclassified parkinsonian syndrome in our clinic between 2001 and 2006. Gold standard was the clinical diagnosis derived from the latest available clinical record, or, when this was not possible, a new complete physical and neurological examination by a blinded movement disorder specialist neurologist. Mean follow-up between SPECT and the latest clinical information was 18 months (range 3 months to 5 years). Results: 223 of the 248 patients were clinically definitely diagnosed after follow-up: IPD 127, atypical parkinsonian syndromes (APS) 27, essential tremor (ET) 22, vascular parkinsonism (VP) 16, drug-induced parkinsonism (DIP) 5, doubt between PD and APS 2, other diseases without dopaminergic involvement 24. The mean odds ratio (95% CI) for FP-CIT SPECT’s ability to distinguish between IPD and ET was 82 (11–674); between IPD and VP 61 (8–490); between IPD and DIP 36 (2–697) and between IPD and APS was 1 (0–4). The odds ratio for the IBZM SPECT tracer to differentiate between IPD and APS was 7 (2–17). Conclusions: FP-CIT SPECT is accurate to differentiate patients with IPD from those with ET, and IPD from VP and DIP. The accuracy of both FP-CIT and IBZM SPECT scans to differentiate between IPD and APS is low.

The diagnostic value of dopamine transporter imaging and olfactory testing in patients with parkinsonian syndromes

“…These results are in accordance with one meta-analysis on the diagnostic accuracy of DaTSCAN [9] and two previously published studies on the same topic [10,34]. However, the putamen/caudate ratio is greater in APS than in PD, suggesting a more uniform dopamine depletion both in putamen and in caudate nucleus in APS patients; this result concurs with the previously discussed visual assessment.…”

“…DaTSCAN imaging has high diagnostic performance in separating patients with PD from patients with non-parkinsonian syndromes [5,6]. However, the efficacy of DaTSCAN imaging in separating PD from APS has been a matter of controversy [4,[7][8][9][10].…”

Diagnostic Accuracy of Combined FP-CIT, IBZM, and MIBG Scintigraphy in the Differential Diagnosis of Degenerative Parkinsonism: A Multidimensional Statistical Approach

“…In the latter regard, SPECT of dopamine D 2 receptors with radioligands such as 123 I-(S)-2-hydroxy-3-iodo-6-methoxy-N-[1-ethyl-2-pyrrodinyl)-methyl]benzamide (IBZM) may be helpful, because APD patients usually display lower D 2 receptor binding than do PD patients (12)(13)(14). Similarly, scintigraphy with meta-123 I-iodobenzylguanidine (MIBG) has recently attracted interest in this context, because it also may differentiate APD and PD based on displaying pronounced cardiac sympathetic denervation in PD (15).…”

Nuclear Medicine Applications in Movement Disorders

“…PH tanısında presinaptik dopaminerjik görüntülemenin tanısal doğruluğu yüksektir. Parkinsonizm tanılı 248 hasta içeren bir prospektif çalışmada klinik izlem sonuçlarına göre SPECT ile DAT görüntüleme bulgularının %80 duyarlılık ve %95 özgüllük ile PH ile ET ayrımını yaptığı; PH ile vasküler ve ilaca bağlı parkinsonizm ayırıcı tanısında ise %80 duyarlılık ve %100 özgüllük gösterdiği bildirilmiştir (46). Presinaptik dopaminerjik görüntülemenin kullanıldığı bir diğer alan da LCD ve AH ayırıcı tanısıdır.…”