[¹²³I]-Ioflupane SPECT in combination with MIBG myocardial scintigraphy in Parkinson’s disease: a case series study

Abstract

Metaiodobenzylguanidine (MIBG) myocardial scintigraphy is widely accepted as a beneficial tool for differentiating Parkinson's disease (PD) from other Parkinson-related disorders (PRD). In Japan, dopamine transporter (DAT) imaging, which can evaluate presynaptic degeneration of dopamine neurons, has been applied in clinics since 2014. The present study investigated the utility of [(123)I]-Ioflupane single photon emission computed tomography (SPECT) combined with MIBG myocardial scintigraphy for the diagnosis of PD. We performed [(123)I]-Ioflupane SPECT and MIBG myocardial scintigraphy in 63 PD patients, 8 PRD patients and 1 essential tremor patient, and obtained the specific binding ratio (SBR [cut-off: 4.5]) and the heart-to-mediastinum ratio (H/M [cut-off: 2.2]). In 70% of the PD patients, both parameters were significantly reduced. In 22% of the PD patients, the SBR was smaller than 4.5 with normal H/M, and H/M was less than 2.2 with normal SBR in 5% of all subjects. Either the SBR or H/M was significantly reduced in 97% of the study population. The SBR showed low disease specificity to PD (11%), and the SBR and H/M negatively correlated with disease duration. These findings indicate that [(123)I]-Ioflupane SPECT combined with MIBG myocardial scintigraphy can improve the detection rate of PD. However, careful interpretation of these results is required because [(123)I]-Ioflupane SPECT poorly differentiates PD from PRD. Progression of PD may reflect the gradual reduction of isotope accumulation, hence, both [(123)I]-Ioflupane SPECT and MIBG myocardial scintigraphy should be tested repeatedly even in clinically suspected PD cases showing negative results.

Optimizing Parkinson’s disease diagnosis: the role of a dual nuclear imaging algorithm

“…123 I-ioflupane SPECT analysis also correlates better with the degree of motor impairment, 60 although 123 I-MIBG uptake has been found to be lower in patients with akinetic-rigid parkinsonism or postural instability gait disorder. 79 On the other hand, as this review has emphasized, MIBG can differentiate PD from other parkinsonian syndromes, 75 , 80 whereas 123 I-ioflupane SPECT cannot. Furthermore, MIBG abnormalities have been associated with typical pre-motor symptoms such as hyposmia, 54 REM-behavior disorder (RBD), 81 and constipation, 82 raising the possibility that MIBG may be more effective at detecting the earliest stages of MLBD, even at the pre-motor stages, and specific non-motor subtypes or routes of pathology spread.…”

“…Furthermore, MIBG abnormalities have been associated with typical pre-motor symptoms such as hyposmia, 54 REM-behavior disorder (RBD), 81 and constipation, 82 raising the possibility that MIBG may be more effective at detecting the earliest stages of MLBD, even at the pre-motor stages, and specific non-motor subtypes or routes of pathology spread. 79 These two imaging techniques have already been used in combination 80 , 83 as a tool to select patients for deep brain stimulation 84 and to sort out patients with mixed tremors 85 and “de novo” PD patients from other forms of parkinsonism. 60 Of note, MIBG is now included as supportive criteria in the revised MDS clinical diagnostic criteria for PD.…”

“…On the basis of the evidence summarized above, the combination of cardiac (MIBG) and cerebral 123 I-ioflupane SPECT could satisfy one of the most significant unmet needs of current PD diagnosis and management, namely the early and accurate diagnosis of patients with typical Lewy body PD. 80 , 87 , 88 Large-scale validation studies of these combined techniques should ideally comprise a sufficient number of subjects in four subgroups of study subjects including patients with idiopathic PD, subject with highly predictive pre-motor symptoms (RBD, hyposmia, and/or other criteria), patients with atypical parkinsonism (MSA or PSP), and normal subjects or patients with essential tremor, as a control group (Fig. 1 ).…”

The usefulness of [123I]‐metaiodobenzylguanidine myocardial scintigraphy in patients with subacute myelo‐optico‐neuropathy

“…12 The H/M ratios of the MIBG examination decreased according to the progression of the Parkinson symptoms and the duration from the onset of PD. 3,4,9,13 MIBG uptake was decreased in most patients with PD and was seen in all advanced cases with H-Y stage III or more. 9 Thus, the significantly decreased H/M ratios in SMON patients with early stages PD were outstanding findings.…”

Use of radioiodine in nuclear medicine—A brief overview

“…The combination of 123 I‐Ioflupane and 123 I‐metaiodobenzylguanidine ( 123 I‐mIBG) has been investigated for its ability to improve the detection of Parkinson's disease 78 . Further research by Yukinori et al 79 was undertaken to determine the usefulness of this combination in the diagnosis of early onset Parkinson's disease.…”