Development of an 123I-metaiodobenzylguanidine Myocardial Three-Dimensional Quantification Method for the Diagnosis of Lewy Body Disease

Abstract

Objective(s): We recently developed a new uptake index method for123I-metaiodobenzylguanidine (123I-MIBG) heart uptake measurements by using planarimages (radioisotope angiography and planar image) for the diagnosis of Lewy bodydisease (LBD), including Parkinson’s disease (PD) and dementia with Lewy bodies(DLB). However, the diagnostic accuracy of the uptake index was approximately equalto that of the heart-to-mediastinum ratio (H/M) for the discrimination of the LBD andnon-LBD patients. A simple and pain-free uptake index method using 123I-MIBG SPECTimages by modifying the uptake index method may show better diagnostic accuracythan the planar uptake index method. We hypothesized that the development of a newuptake index method for the determination of 123I-MIBG using single-photon emissioncomputed tomography (SPECT) imaging would provide a reliable and reproduciblediagnostic tool for clinical application. Regarding this, the purpose of this study wasto develop a new uptake index method with a simple protocol to determine 123I-MIBGuptake on SPECT.Methods: The 123I-MIBG input function was determined from the input counts of thepulmonary artery, assessed by analyzing the pulmonary artery time-activity curves.The 123I-MIBG output function was obtained from 123I-MIBG SPECT counts on the polarmap. The uptake index was calculated through dividing the output function by theinput function (SPECT uptake method). For the purpose of the study, 77 patientsunderwent 123I-MIBG SPECT, with an average of 31.5 min after clinical assessment andinjection of the tracer. The H/M values, as well as planar and SPECT uptake indiceswere calculated, and then correlated with clinical features.Results: According to the results, values obtained for LBD were significantly lower thanthose for non-LBD in all analyses (P

Keywords

• Iodine-123 metaiodobenzylguanidine
• Lewy body disease
• Quantification
• Single-photon emission tomography