Metaiodobenzylguanidine (MIBG) is an analog of norepinephrine that accumulates in sympathetic nerve endings soon after intravenous administration. The degree of accumulation reflects the uptake, storage and release of transmitters by noradrenergic neurons. Myocardial imaging with ¹²³I labeled MIBG ( ¹²³I-MIBG) can be used to estimate the extent of local myocardial sympathetic nerve damage, which has been widely used in the diagnosis and treatment of various heart diseases. In recent years, numerous studies have been carried out on the application of ¹²³I-MIBG in the diagnosis of degenerative diseases of the nervous system (such as Parkinson's disease and dementia of Lewy body), and have made some achievements. The purpose of this review is to summarize the current clinical application of ¹²³I-MIBG myocardial imaging in the diagnosis of dementia with Lewy bodies, the problems in imaging technology and the possible research directions in the future, so as to provide valuable reference information for clinicians to reasonably and accurately apply this technology in the early diagnosis and discrimination of dementia.
Humans ; Lewy Bodies ; 3-Iodobenzylguanidine ; Lewy Body Disease/diagnostic imaging* ; Iodine Radioisotopes

The objective of this case report is to highlight the role of Iodine-131 metaiodobenzylguanidine (MIBG) cardiac scintigraphy in discriminating Dementia with Lewy Bodies (DLB) from other neurodegenerative diseases such as Alzheimer’s Disease. This patient is a known case of Parkinson’s disease and has been treated as such since 2011. However, the patient also concurrently deals with visual hallucinations and because of this, the patient’s attending neurologist wanted to rule in the diagnosis of DLB rather than AD. Hence, an I-131 MIBG cardiac scan was requested in order to support the diagnosis of DLB. The use of I-131 MIBG cardiac scintigraphy as a diagnostic tool for diagnosing Lewy Body Dementia is not prevalent and to our knowledge, this was the first time in the country that this procedure was done (December 9, 2019).
3-Iodobenzylguanidine ; Lewy Body Disease ; Radionuclide Imaging

Nuclear theranostics functions as a bridge which connects targeted diagnosis to targeted therapy, just like Turkey functions as a geographical bridge which connects Asia to Europe. This unique geographical site of the country plays an important role with regard to introduction of novel scientific and technologic improvements, which originate from one continent to another, in the era of accelerated information. The first nuclear medicine practice in Turkey started in the beginning of 1950s with the first radioiodine treatment, which actually was a debut for nuclear theranostics in Turkey, years before many other countries in the world. For the time being, along with radioiodine treatment, many other theranostic applications such as I-131 MIBG treatment, Lu-177/Y-90 DOTA peptide treatment, Lu-177 PSMA treatment, Y-90 microsphere treatment, and bone palliative treatment are being performed in many centers countrywide. As science and technology improves, novel theranostic applications are eagerly awaited to be introduced in near future. This paper summarizes the story of nuclear theranostics in Turkey and aims to give an overview on the current status of theranostic applications in Turkey.
3-Iodobenzylguanidine ; Asia ; Diagnosis ; Europe ; Microspheres ; Nuclear Medicine ; Palliative Care ; Theranostic Nanomedicine ; Turkey

Metaiodobenzylguanidine (MIBG) is structurally similar to the neurotransmitter norepinephrine and specifically targets neuroendocrine cells including some neuroendocrine tumors. Iodine-131 (I-131)-labeled MIBG (I-131 MIBG) therapy for neuroendocrine tumors has been performed for more than a quarter-century. The indications of I-131 MIBG therapy include treatment-resistant neuroblastoma (NB), unresectable or metastatic pheochromocytoma (PC) and paraganglioma (PG), unresectable or metastatic carcinoid tumors, and unresectable or metastatic medullary thyroid cancer (MTC). I-131 MIBG therapy is one of the considerable effective treatments in patients with advanced NB, PC, and PG. On the other hand, I-131 MIBG therapy is an alternative method after more effective novel therapies are used such as radiolabeled somatostatin analogs and tyrosine kinase inhibitors in patients with advanced carcinoid tumors and MTC. No-carrier-aided (NCA) I-131 MIBG has more favorable potential compared to the conventional I-131 MIBG. Astatine-211-labeled meta-astatobenzylguanidine (At-211 MABG) has massive potential in patients with neuroendocrine tumors. Further studies about the therapeutic protocols of I-131 MIBG including NCA I-131 MIBG in the clinical setting and At-211 MABG in both the preclinical and clinical settings are needed.
3-Iodobenzylguanidine ; Carcinoid Tumor ; Consensus ; Hand ; Humans ; Methods ; Neuroblastoma ; Neuroendocrine Cells ; Neuroendocrine Tumors ; Neurotransmitter Agents ; Norepinephrine ; Paraganglioma ; Pheochromocytoma ; Protein-Tyrosine Kinases ; Somatostatin ; Thyroid Neoplasms

PURPOSE: Diagnostic I-131 MIBG scintigraphy is an important imaging modality for evaluation of patients with neuroblastoma (NB) especially in centers where I-123 MIBG is not available. Single photon emission computed tomography/computed tomography (SPECT/CT) could potentially improve lesion detection over planar scintigraphy, but studies regarding its usefulness as an add-on to diagnostic I-131 MIBG scintigraphy are limited. This study aimed to determine the usefulness and factors related to usefulness of SPECT/CT in diagnostic I-131 MIBG scintigraphy in NB patients.METHODS: Usefulness of SPECT/CT for lesion detection, lesion localization, resolving suspicious findings, and clarifying the nature of lesions on anatomical imaging were retrospectively reviewed in 86 diagnostic planar I-131 MIBG scintigrams with add-on SPECT/CT.RESULTS: SPECT/CT detected additional lesions in 23.2%(20/86), helped localize lesions in 21.1%(8/38), resolved suspicious findings in 85.7%(6/7), determined functional status of lesions on anatomical imaging in 94.4%(17/18), and changed diagnosis from a negative to a positive study in 19.5%(8/41). Independent predictors of SPECT/CT being useful included presence of suspicious findings on planar imaging (OR 99.08; 95% C.I. 6.99–1404.41; p = 0.001), positive findings on planar imaging (OR 4.61; 95% C.I. 1.05, 20.28; p < 0.001), and presence of structural lesions on anatomical imaging (OR 32.54; 95% C.I. 5.37–196.96; p < 0.001).CONCLUSION: SPECT/CT is a useful add-on to diagnostic planar I-131 MIBG scintigraphy. Predictors of usefulness of SPECT/CT include suspicious or positive findings on planar scintigraphy and the presence of structural lesions on anatomical imaging.
3-Iodobenzylguanidine ; Diagnosis ; Humans ; Neuroblastoma ; Radionuclide Imaging ; Retrospective Studies

PURPOSE: ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging is well known to have clinical significance in the initial staging and response evaluation of the many kinds of neoplasms. However, its role in the pediatric neuroblastoma is not clearly defined. In the present study, the clinical significance of FDG-PET/computed tomography (CT) in ¹²³I- or ¹³¹I-metaiodobenzylguanidine (MIBG)-avid pediatric neuroblastoma was investigated.METHODS: Twenty patients with neuroblastoma who undertook pretreatment FDG PET/CT at our institute between 2008 and 2015 and showed MIBG avidity were retrospectively enrolled in the present study. Clinical information—including histopathology, and serum markers—and several PET parameters—including SUVmax of the primary lesion (Psuv), target-to-background ratio (TBR), metabolic tumor volume (MTV), and coefficient of variation (CV)—were analyzed. The prognostic effect of PET parameters was evaluated in terms of progression-free survival (PFS).RESULTS: Total 20 patients (4.5 ± 3.5 years) were divided as two groups by disease progression. Six patients (30.0 %) experienced disease progression and one patient (5.0 %) died during follow-up period. There were not statistically significant in age, stage, MYCN status, primary tumor size, serum lactate dehydrogenase (LDH), neuron-specific enolase (NSE), and ferritin level between two groups with progression or no progression. However, Psuv (p = 0.017), TBR (p = 0.09), MTV (p = 0.02), and CV (p = 0.036) showed significant differences between two groups. In univariate analysis, PFS was significantly associated with Psuv (p = 0.021) and TBR (p = 0.023).CONCLUSIONS: FDG-PET parameters were significantly related with progression of neuroblastoma. FDG-PET/CT may have the potential as a valuable modality for evaluating prognosis in the patients with MIBG-avid pediatric neuroblastoma.
3-Iodobenzylguanidine ; Disease Progression ; Disease-Free Survival ; Ferritins ; Follow-Up Studies ; Humans ; L-Lactate Dehydrogenase ; Neuroblastoma ; Pediatrics ; Phosphopyruvate Hydratase ; Positron-Emission Tomography and Computed Tomography ; Prognosis ; Retrospective Studies ; Tumor Burden

A 9-year-old boy presented with increased sweating and abdominal pain. His mother and uncle had been diagnosed with bilateral pheochromocytoma and medullary thyroid carcinoma. Magnetic resonance imaging of the boy's abdomen revealed a 7.5 cm×7.0 cm×6.0 cm mass with a thick peripheral enhancing wall and fluid-fluid level at the right suprarenal region. His ¹²³I-meta-iodobenzylguanidine (MIBG) scan showed a large mass with increased MIBG uptake in the right adrenal gland. The levels of serum norepinephrine, urine epinephrine/norepinephrine, metanephrine, and vanillylmandelic acid were elevated. He, his mother, and two sisters tested positive for the known mutation of multiple endocrine neoplasia type 2A, Cys634Tyr in RET proto-oncogene. Laparoscopic tumor excision and right adrenalectomy were performed. Final diagnosis was pheochromocytoma with malignant behavior, based on adrenal gland scoring scale. However, there was no overt metastasis. After surgery, his symptoms resolved and abnormal laboratory tests were normalized.
3-Iodobenzylguanidine ; Abdomen ; Abdominal Pain ; Adrenal Glands ; Adrenalectomy ; Child ; Diagnosis ; Humans ; Magnetic Resonance Imaging ; Male ; Metanephrine ; Mothers ; Multiple Endocrine Neoplasia Type 2a ; Multiple Endocrine Neoplasia ; Neoplasm Metastasis ; Norepinephrine ; Pheochromocytoma ; Proto-Oncogenes ; Siblings ; Sweat ; Sweating ; Thyroid Neoplasms ; Vanilmandelic Acid

Rarely, a paraganglioma can lead to disastrous cardiac complications such as heart failure, cardiomyopathy, or myocardial infarction and inflammatory complications such as sepsis. We describe a 41-year-old man who developed severe dilated cardiomyopathy with cardiogenic shock and sepsis who had a paraganglioma in the retroperitoneum. Echocardiography showed extensive global hypokinesia with severe left ventricular systolic dysfunction. In addition, leukocytosis with elevated inflammatory markers and positive blood cultures indicated sepsis. Abdominal enhanced computed tomography and magnetic resonance imaging showed a large heterogeneous mass with cystic changes in the retroperitoneum. Serum and urine samples indicated elevated levels of catecholamine and its metabolites, and a 131I-meta-iodobenzylguanidine (MIBG) scan indicated uptake of MIBG. After intensive medical treatment and surgical removal of the paraganglioma, the dilated cardiomyopathy and sepsis resolved. The diagnosis of paraganglioma should be considered in patients presenting with acute heart failure or sepsis of nonspecific origin.
3-Iodobenzylguanidine ; Adult ; Cardiomyopathies ; Cardiomyopathy, Dilated* ; Diagnosis ; Echocardiography ; Heart Failure ; Humans ; Hypokinesia ; Leukocytosis ; Magnetic Resonance Imaging ; Myocardial Infarction ; Paraganglioma* ; Pheochromocytoma ; Sepsis* ; Shock, Cardiogenic*

¹²³I-meta-iodobenzylguanidine (MIBG) has become widely applied in Japan since its introduction to clinical cardiology and neurology practice in the 1990s. Neurological studies found decreased cardiac uptake of ¹²³I-MIBG in Lewy-body diseases including Parkinson's disease and dementia with Lewy bodies. Thus, cardiac MIBG uptake is now considered a biomarker of Lewy body diseases. Although scintigraphic images of ¹²³I-MIBG can be visually interpreted, an average count ratio of heart-to-mediastinum (H/M) has commonly served as a semi-quantitative marker of sympathetic activity. Since H/M ratios significantly vary according to acquisition and processing conditions, quality control should be appropriate, and quantitation should be standardized. The threshold H/M ratio for differentiating Lewy-body disease is 2.0-2.1, and was based on standardized H/M ratios to comparable values of medium-energy collimators. Parkinson's disease can be separated from various types of parkinsonian syndromes using cardiac ¹²³I-MIBG, whereas activity is decreased on images of Lewy-body diseases using both ¹²³I-ioflupane for the striatum and ¹²³I-MIBG. Despite being a simple index, the H/M ratio of ¹²³I-MIBG uptake is reproducible and can serve as an effective tool to support a diagnosis of Lewy-body diseases in neurological practice.
3-Iodobenzylguanidine ; Cardiology ; Dementia ; Diagnosis ; Japan ; Lewy Bodies ; Lewy Body Disease ; Neurology ; Nuclear Medicine ; Parkinson Disease ; Parkinsonian Disorders ; Quality Control

Cardioprotective effect of fimasartan, a new angiotensin receptor blocker (ARB), was evaluated in a porcine model of acute myocardial infarction (MI). Fifty swine were randomized to group 1 (sham, n=10), group 2 (no angiotensin-converting enzyme inhibitor [ACEI] or ARB, n=10), group 3 (perindopril 2 mg daily, n=10), group 4 (valsartan 40 mg daily, n=10), or group 5 (fimasartan 30 mg daily, n=10). Acute MI was induced by occlusion of the left anterior descending artery for 50 min. Echocardiography, single photon emission computed tomography (SPECT), and F-18 fluorodeoxyglucose cardiac positron emission tomography (PET) were performed at baseline, 1 week, and 4 weeks. Iodine-123 meta-iodobenzylguanidine (MIBG) scan was done at 6 weeks for visualization of cardiac sympathetic activity. Left ventricular function and volumes at 4 weeks were similar between the 5 groups. No difference was observed in groups 2 to 5 in SPECT perfusion defect, matched and mismatched segments between SPECT and PET at 1 week and 4 weeks. MIBG scan showed similar uptake between the 5 groups. Pathologic analysis showed similar infarct size in groups 2 to 5. Infarct size reduction was not observed with use of fimasartan as well as other ACEI and ARB in a porcine model of acute MI.
3-Iodobenzylguanidine ; Angiotensin II Type 1 Receptor Blockers/therapeutic use ; Angiotensin Receptor Antagonists/*therapeutic use ; Angiotensin-Converting Enzyme Inhibitors/therapeutic use ; Animals ; Anterior Wall Myocardial Infarction/*drug therapy/physiopathology ; Biphenyl Compounds/*therapeutic use ; Cardiotonic Agents/*therapeutic use ; Disease Models, Animal ; Echocardiography ; Fluorodeoxyglucose F18 ; Perindopril/therapeutic use ; Positron-Emission Tomography ; Pyrimidines/*therapeutic use ; Random Allocation ; Swine ; Tetrazoles/*therapeutic use ; Tomography, Emission-Computed, Single-Photon ; Valsartan/therapeutic use ; Ventricular Function, Left/*physiology