The clinical value of 123I-metaiodobenzylguanidine myocardial imaging in the diagnosis of dementia with Lewy bodies / 生物医学工程学杂志

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.

Clinical significance of vanillylmandelic acid in neuroblastoma

Background: The second most common solid tumor in children is Neuroblastoma (NB). In about 90% of cases of NB, elevated levels of catecholamines or its metabolites are found in the urine or blood which includes Vanillylmandelic Acid (VMA) and Homovanillic Acid (HVA). Ferritin, Neuron-Specific Enolase (NSE) and Lactate Dehydrogenase (LDH) are commonly assessed in children suspected to have NB, and the levels of these markers are commonly used for differential diagnosis. Multiple clinical and imaging tests are needed for accurate patient assessment. Iodine 123(123I) Metaiodobenzylguanidine (MIBG) is the first-line functional imaging agent used in neuroblastoma imaging. To evaluate the utility of these marker present study was undertaken with 91 NB patients and 40 normal healthy control.Methods: The study comprised of blood samples and 24 hour抯 urine sample from 40 normal healthy subjects and 91 untreated patients with histologically proven Stage III and IV NB cases referred to our institute. Method used for NSE was Enzyme Immunoassay (Elisa), serum Ferritin was MIA, LDH-photometry and VMA by Column Chromatography.Results: Amongst the parameters studied VMA showed highest sensitivity (91%), specificity (94.4%) positive predictive value (97.8%) and 85% negative predictive value at the cut off levels of 7mg/ ml of creatinine as compared to other studied parameters.Conclusions: This study suggests that the detection of VMA in combination with routine histological examination, MIBG scan, serum NSE and LDH may improve the diagnosis of Neuroblastoma.

Sympathetic Dysautonomia in Heart Failure by 123I-MIBG: comparison between Chagasic, non-Chagasic and heart transplant patients / Disautonomia Simpática na Insuficiência Cardíaca pela 123I-MIBG: Comparação entre Pacientes Chagásicos, não-Chagásicos e Transplantados Cardíacos

Abstract Background: Heart failure (HF) is a severe public health problem because of its high morbidity and mortality and elevated costs, thus requiring better understanding of its course. In its complex and multifactorial pathogenesis, sympathetic hyperactivity plays a relevant role. Considering that sympathetic dysfunction is already present in the initial phases of chronic Chagas cardiomyopathy (CCC) and frequently associated with a worse prognosis, we assumed it could be more severe in CCC than in cardiomyopathies of other etiologies (non-CCC). Objectives: To assess the cardiac sympathetic dysfunction 123I-MIBG) of HF, comparing individuals with CCC to those with non-CCC, using heart transplant (HT) patients as denervated heart parameters. Methods: We assessed 76 patients with functional class II-VI HF, being 25 CCC (17 men), 25 non-CCC (14 men) and 26 HT (20 men), by use of cardiac 123I-metaiodobenzylguanidine 123I-MIBG) scintigraphy, estimating the early and late heart-to-mediastinum ratio (HMR) of 123I-MIBG uptake and cardiac washout (WO%). The 5% significance level was adopted in the statistical analysis. Results: The early and late HMR values were 1.73 ± 0.24 and 1.58 ± 0.27, respectively, in CCC, and 1.62 ± 0.21 and 1.44 ± 0.16 in non-CCC (p = NS), being, however, higher in HT patients (p < 0.001). The WO% values were 41.65 ± 21.4 (CCC), 47.37 ± 14.19% (non-CCC) and 43.29 ± 23.02 (HT), p = 0.057. The late HMR values showed a positive weak correlation with left ventricular ejection fraction (LVEF) in CCC and non-CCC (r = 0.42 and p = 0.045; and r = 0.49 and p = 0.015, respectively). Conclusion: Sympathetic hyperactivity 123I-MIBG) was evidenced in patients with class II-IV HF, LVEF < 45%, independently of the HF etiology, as compared to HT patients.

Resumo Fundamentos: A insuficiência cardíaca (IC) representa um grave problema de saúde pública pela alta morbimortalidade e custos envolvidos, exigindo uma melhor compreensão de sua evolução. Em sua patogênese, complexa e multifatorial, a hiperatividade simpática ocupa relevante papel. Considerando que a disfunção simpática está presente já nas fases iniciais da cardiopatia chagásica crônica (CCC), frequentemente associando-se a um pior prognóstico, supomos que pudesse ser mais grave na CCC que nas demais etiologias (não-CCC). Objetivos: Avaliar a disfunção simpática cardíaca (123I-MIBG) da IC, comparando-se os portadores de CCC aos não-CCC, utilizando os pacientes transplantados cardíacos (TC) como parâmetro de coração desnervado. Métodos: Estudamos 76 pacientes com IC classe funcional II-VI, sendo 25 CCC (17 homens), 25 não-CCC (14 homens) e 26 TC (20 homens), pela cintilografia cardíaca (123I-MIBG), estimando-se a captação (HMR) precoce e tardia e o washout cardíaco (Wc%). Nas análises estatísticas, o nível de significância foi de 5%. Resultados: Os valores da HMR precoce e da tardia foram 1,73 ± 0,24 e 1,58 ± 0,27, respectivamente, na CCC, e 1,62 ± 0,21 e 1,44 ± 0,16 na não-CCC (p = NS), sendo, porém, mais elevados nos TC (p < 0,001). Os valores de Wc% foram 41,65 ± 21,4 (CCC), 47,37 ± 14,19% (não-CCC) e 43,29 ± 23,02 (TC), p = 0,057. Os valores de HMR tardia apresentaram correlação positiva fraca com a fração de ejeção de ventrículo esquerdo (FEVE) na CCC e na não-CCC (r = 0,42 e p = 0,045; e r = 0,49 e p = 0,015, respectivamente). Conclusão: Evidenciou-se a presença de hiperatividade simpática (123I-MIBG) em pacientes com IC classe II-IV, FEVE < 45%, independentemente da etiologia da IC, quando comparados aos pacientes TC.

Current Consensus on I-131 MIBG Therapy / 대한핵의학회잡지

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.

Comparison of Diagnosing and Staging Accuracy of PET (CT) and MIBG on Patients with Neuroblastoma: Systemic Review and Meta-analysis / 华中科技大学学报（医学）（英德文版）

To perform a systemic review and meta-analysis of the diagnostic accuracy of PET (CT) and metaiodobenzylguanidine (MIBG) for diagnosing neuroblastoma (NB),electronic databases were searched as well as relevant references and conference proceedings.The diagnostic accuracy of MIBG and PET (CT) was calculated for NB,primary NB,and relapse/metastasis of NB based on their sensitivity,specificity,and area under the summary receiver operating characteristic curve (AUSROC) in terms of per-lesion and per-patient data.A total of 40 eligible studies comprising 1134 patients with 939 NB lesions were considered for the meta-analysis.For the staging of NB,the per-lesion AUSROC value of MIBG was lower than that of PET (CT) [0.8064±0.0414 vs.0.9366±0.0166 (P＜0.05)].The per-patient AUSROC value of MIBG and PET (CT) for the diagnosis of NB was 0.8771±0.0230 and 0.6851±0.2111,respectively.The summary sensitivity for MIBG and PET (CT) was 0.79 and 0.89,respectively.The summary specificity for MIBG and PET (CT) was 0.84 and 0.71,respectively.PET (CT) showed higher per-lesion accuracy than MIBG and might be the preferred modality for the staging of NB.On the other hand,MIBG has a comparable diagnosing performance with PET (CT) in per-patient analysis but shows a better specificity.

The first MIBG therapy in the Philippines

Neuroblastoma is an embryonal tumor of children that frequently presents with metastases. Our patient is a 6-year-old girl who was diagnosed to have neuroblastoma with diffuse metastatic disease throughout the skeleton as seen in her 123I-MIBG scan in the United States. 18F-FDG PET/CT scan was done in the Philippines after chemotherapy and gene therapy, and before 131I-MIBG therapy. No additional lesions were seen on PET.  131I-MIBG was then performed and an 131I-MIBG with SPECT/CT thereafter, which showed an increase in size and extent of the lesion in the head and a decrease in number of the skeletal metastases. New 131I-MIBG-avid posterior cervical lymph nodes were also localized through SPECT/CT. For this patient, a follow-up 123I/131I-MIBG scan would be more cost-effective in assessing response to therapy. Sectional imaging may be done to obviate the need for sedation of this young patient.

Clinical efficacy of 131I-MIBG therapy in malignant pheochromocytoma/malignant paraganglioma / 中华泌尿外科杂志

Objective To evaluate the efficacy and safety of 131I-metaiodobenzylguanidine (131 I-MIBG) in treatment of malignant pheochromocytoma/malignant paraganglioma (MPHEO/MPGL).Methods The clinical data of 96 cases of MPHEO/MPGL (60/36) treated with 131I-MIBG between December 1998 and April 2014 were retrospectively reviewed.Among them,the malignant pheochromocytoma was found in 60 cases and malignant paraganglioma was found in 36 cases.Seventy-eight patients (81.2％)presented initially with hypertension,whereas 18 patients (18.8％) presented adrenal incidentaloma.Before 131I-MIBG treatment,24 h urinary norepinephrine was (409.5± 127.2) nmol,24 h urinary dopamine was (99.3±41.1) nmol,24 h urine adrenaline was (1 409.9±336.0) nmol.Before treatment,the compound iodine solution was given to each one.Then,all patients were given an initial course of 131I-MIBG therapy (5.55,7.40 GBq).Subsequent 131I-MIBG treatment (5.55,7.40 GBq) was undertaken every three to six months.The patients got symptomatic,hormonal or radiological response underwent sbsequent 131I-MIBG therapy (3.70,5.55 GBq) every year.All patients underwent clinical symptoms (headache,palpitate,sweating,hypertension),biochemical (24 h urine catecholamin) and radiological evaluation (CT/MRI) within 6 months to evaluate the efficacy and safety of 131I-MIBG treatment.Results After one to eleven sessions of 131 I-MIBG treatment,in total,266 doses of 131 I-MIBG were administered,average dose was 6.49 GBq.22.9％ of patients demonstrated radiological partial response (≥ 50％ reduction in tumor size) after first or repeated 131 I-MIBG treatment.Eleven cases (11.5％) achieved clinical complete response,41 cases (42.7％) achieved clinical partial response and 23 cases (24.0％) maintained the stable clinic symptoms.After treatment,24 h urinary norepinephrine (164.3±71.6) nmol and dopamine (49.7±24.7) nmol showed significantly decline,compared with those before treatment (P＜ 0.05).While,24 h urinary epinephrine (1 354.7±433.4) nmol had no obvious change (P＞0.05).No life-threatening adverse events were reported,but 2 MPGL patients developed transient leucopenia or thrombocytopenia after four and five times 131 I-MIBG treatment,respectively.Conclusions Treatment with repeated low dose 131I-MIBG is well tolerated and effective in controlling the progression and alleviating the clinical symptoms.The 131I-MIBG therapy is an effective and safe treatment modality for MPHEO/MPGL.

A Case Report of Recurrent Malignant Paraganglioma with Lung and Spine Metastasis that Occurred Sixteen Years after Primary Tumor Excision / 대한내과학회지

Paragangliomas are rare tumors that arise from the extra-adrenal chromaffin cells, and malignancy is defined by the presence of metastases to sites that normally lack chromaffin tissue. The main therapeutic targets are tumor reduction and control of excessive catecholamine secretion. Currently, the adjuvant therapy to surgery is radiotherapy treatment using high-dose MIBG; chemotherapy is currently evolving. We report herein a case of malignant paraganglioma with lung and spine metastasis that occurred 16 years after primary tumor excision and was treated with high dose MIBG radiotherapy and chemotherapy.

Relevancia de la medicina nuclear en el diagnóstico y tratamiento del paraganglioma maligno / Relevance of nuclear medicine in the diagnosis and treatment of malignant paraganglioma

Introducción: Los paragangliomas son tumores del tejido cromafín caracterizados por la síntesis o secreción de catecolaminas, en los que el tratamiento depende de su extensión y características funcionales. Dentro de la evaluación diagnóstica anatómica y funcional de este padecimiento, los métodos de imagen de medicina nuclear sobresalen por su utilidad. Caso clínico: Paciente con paraganglioma a nivel de la bifurcación de la aorta en quien el diagnóstico se realizó por estudios de laboratorio, imagenología y medicina nuclear. Se llevó a cabo centelleografía con un análogo de norepinefrina, la metayodobencilguanidina marcada radiactivamente (131I-MIBG), que demostró funcional y específicamente la presencia de tejido adrenérgico neoplásico y su extensión extratumoral. Complementariamente se efectuó tomografía por emisión de positrones fusionada con tomografía computarizada, utilizando un análogo radiactivo de la glucosa que localizó la actividad extratumoral a nivel óseo. Los estudios de medicina nuclear permitieron concluir que se trataba de un paraganglioma maligno con metástasis óseas. El tratamiento incluyó resección quirúrgica del tumor y ablación del tejido tumoral residual y de los focos metastásicos con radioterapia interna mediante 131I-MIBG. El tratamiento radioterapéutico fue posible dada la capacidad del tumor y las metástasis de concentrar el análogo hormonal radiactivo. Conclusiones: Ante casos de paragangliomas, además de la localización del tumor y la evaluación de las alteraciones bioquímicas, es indispensable la evaluación funcional que brinda la medicina nuclear para la realización de un diagnóstico y tratamiento adecuados.

BACKGROUND: Paragangliomas are neoplasms of the chromaffin tissue characterized by the synthesis and/or secretion of catecholamines. Their treatment depends on the extension and functional characteristics of the tumor. In this pathology, the anatomic and functional diagnostic evaluations provided by nuclear medicine imaging studies have significant usefulness. CLINICAL CASE: A 34-year-old male was diagnosed with a paraganglioma at the level of the aortic bifurcation by means of laboratory tests, imaging studies and nuclear medicine studies. Nuclear medicine was carried out with a scintigraphy with a norepinephrine analog, radioactive meta-iodo-benzyl-guanidine (131I-MIBG), which demonstrates functionally and specifically the presence of neoplastic adrenergic tissue and extratumoral extension. In addition, a positron emission tomography coupled with computed tomography with a radioactive analog of glucose locates the extratumoral activity at bone level. Nuclear medicine studies allow the diagnosis of a malignant paraganglioma with presence of bone metastasis. The therapy includes surgical removal of the tumor and ablation of residual malignant tissue and metastatic lesions by radiotherapy with 131I-MIBG. Radiotherapeutic treatment was possible due to the capacity of the tumor to uptake and to concentrate the radioactive hormonal analog. CONCLUSIONS: In cases of paraganglioma, in addition to the localization of the tumor and the evaluation of biochemical alterations, it is indispensable to obtain anatomic and functional evaluation provided by nuclear medicine studies in order to achieve appropriate diagnoses and treatment.

A Discrepancy between (131)I-Metaiodobenzylguanidine ((131)I-MIBG) Scintigraphy and (18)F-FDG PET/CT after (131)I-MIBG Therapy in a Patient with Recurred Malignant Pheochromocytoma / 핵의학분자영상

A 59-year-old woman who was diagnosed with malignant pheochromocytoma underwent (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT). She had undergone left adrenalectomy for pheochromocytoma 4 years previously. Recent multiple metastatic pulmonary nodules were noted on the chest X-ray. After treatment with (131)I-metaiodobenzylguanidine ((131)I-MIBG) with 7.4 GBq, post-therapy (131)I-MIBG scintigraphy depicted multiple distant metastases including lung, liver, abdominal para-aortic and mesenteric lymph nodes. (18)F-FDG PET/CT also depicted multiple metastases in lung, liver, and abdominal para-aortic lymph nodes, but some lesions were not shown. In this case, (131)I-MIBG scintigraphy found additional lesions in metastatic malignant pheochromocytoma.

Imaging Improves Diagnosis of Dementia with Lewy Bodies

Dementia with Lewy bodies (DLB) is the second most common cause of degenerative dementia after Alzheimer's disease (AD), and is clinically characterized by the progressive cognitive decline with fluctuations in cognition and alertness, recurrent visual hallucinations and Parkinsonism. Once these characteristic symptoms of DLB emerge, discriminating it from AD is relatively easy. However, in the early disease stages, the clinical symptoms of various types of dementias largely overlap and it is difficult to distinguish DLB from other neurodegenerative dementias based on clinical manifestations alone. To increase the accuracy of antemortem diagnosis of DLB, the latest diagnostic criteria incorporate findings from 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, or from neuroimaging such as computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). In the present guidelines, decreased dopamine transporter uptake revealed by SPECT or PET receives the greatest importance among various neuroimaging findings and is listed as one of the suggestive features. Supportive features that commonly present but are not proven to have diagnostic specificity include relatively-preserved medial-temporal-lobe structures, occipital hypoperfusion, and abnormal MIBG myocardial scintigraphy. In this paper, we review the major findings on various neuroimaging modalities and discuss the clinical usefulness of them for the diagnosis of DLB. Although there is not enough evidence to reach the conclusion, considering the accessibility in clinical practice, in our personal views, we recommend the use of brain-perfusion SPECT and MIBG myocardial scintigraphy to improve the diagnosis of DLB.

Imaging Improves Diagnosis of Dementia with Lewy Bodies

Dementia with Lewy bodies (DLB) is the second most common cause of degenerative dementia after Alzheimer's disease (AD), and is clinically characterized by the progressive cognitive decline with fluctuations in cognition and alertness, recurrent visual hallucinations and Parkinsonism. Once these characteristic symptoms of DLB emerge, discriminating it from AD is relatively easy. However, in the early disease stages, the clinical symptoms of various types of dementias largely overlap and it is difficult to distinguish DLB from other neurodegenerative dementias based on clinical manifestations alone. To increase the accuracy of antemortem diagnosis of DLB, the latest diagnostic criteria incorporate findings from 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, or from neuroimaging such as computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). In the present guidelines, decreased dopamine transporter uptake revealed by SPECT or PET receives the greatest importance among various neuroimaging findings and is listed as one of the suggestive features. Supportive features that commonly present but are not proven to have diagnostic specificity include relatively-preserved medial-temporal-lobe structures, occipital hypoperfusion, and abnormal MIBG myocardial scintigraphy. In this paper, we review the major findings on various neuroimaging modalities and discuss the clinical usefulness of them for the diagnosis of DLB. Although there is not enough evidence to reach the conclusion, considering the accessibility in clinical practice, in our personal views, we recommend the use of brain-perfusion SPECT and MIBG myocardial scintigraphy to improve the diagnosis of DLB.

The Efficacy of MIBG Scan as a Diagnostic and Docalization Test for Pheochromocytoma / 대한내분비학회지

BACKGROUND: Computed tomography(CT) is currently considered as the initial imaging procedure of choice for the localization of pheochromocytomas in most of the cases. 131I-or 123I-Metaiodobenzylguanidine scintigraphy(MIBG scan) was proven to be a highly specific tool for the detection of adrenal and extra-adrenal pheochromocytomas, but was less sensitive than CT. The present study is aimed to evaluate the usefulness of a MIBG scan in diagnosis and localization of pheochromocytoma when compared to CT. METHODS: We retrospectively evaluated 27 patients who underwent a MIBG scan for a pheochromocytoma at the Seoul National University Hospital from the year 2000 and 2002. According to the pathological and clinical findings, in 16 the patients pheochromocytoma was confirmed to be positive and the rest 11 of the patients were excluded from the study. RESULTS: Pheochromocytomas was identified in 16 patients. Eleven of them were localized in adrenal gland and 5 were extra-adrenal lesions. The sensitivity to MIBG scan in adrenal lesions and extra-adrenal lesions, was 72%(8/11) and 40%(2/5) respectively. In our study, the overall sensitivity to MIBG scan was 62%(10/16), and overall specificity was 90.9%(10/11). By CT four were identified to have equivocal biochemical abnormalities, but were definite and extraadrenal tumors by MIBG scan showed abnormal uptakes in two of them. CONCLUSION: The MIBG scan was especially useful in 2 of the 27 patients but we had no experienced about the additional benefits of a MIBG scan in the other 25 cases. Our results reveal that a MIBG scan should be performed carefully for the diagnosis and localization of a pheochromocytoma, while considering cost and time of operation.

Assessment of myocardial metaiodobenzylguanidine uptake and its relation to left ventricular systolic and diastolic functional parameters in dilated cardiomyopathy

The purpose of this study was to assess the relation between myocardial metaiodobenzylguanidine (MIBG) uptake and left ventricular systolic and diastolic functional parameters, both of which are known as predictors of prognosis in patients with dilated cardiomyopathy. Echocardiography and iodine-123-MIBG myocardial scintigraphy were performed in 35 patients of dilated cardiomyopathy with normal sinus rhythm. Mean myocardial MIBG uptake in the patient group at early and delayed images were significantly lower than those in normal control subjects (10.6 +/- 1.1, 9.8 +/- 1.2 vs 12.4 +/- 1.0, 12.1 +/- 1.0, p 0.05). There were no significant correlations between myocardial MIBG uptake, expressed as the ratio of heart/mediastinum MIBG activity at delayed image, and left ventricular systolic and diastolic functional parameters ?left ventricular ejection fraction, left ventricular end-diastolic dimension, peak velocity of early diastolic filling (E velocity), deceleration time of E wave, cardiac output, left ventricular end-diastolic pressure?. In conclusion, the myocardial uptake of MIBG is decreased in patients with dilated cardiomyopathy assessed by iodine-123-MIBG myocardial scintigraphy. There were, however, no significant correlations between myocardial MIBG uptake and left ventricular systolic and diastolic functional parameters derived from echocardiography.

Assessment of cardiac sympathetic neuronal integrity using iodine-123 metaiodobenzylguanidine myocardial scintigraphy and its clinical efficacy as a new noninvasive screening test for the diagnosis of coronary artery spasm

BACKGROUND: It has been suggested that the sympathetic nervous system might play an important role in the development of coronary artery spasm. Recently, advances have made possible the imaging of the cardiac adrenergic nervous system with metaiodobenzylguanidine (MIBG) labeled with iodine-123. The purpose of this study was to assess the presence and location of abnormal sympathetic innervation by iodine-123-metaiodobenzylguanidine single-photon emission computed tomography (SPECT) and to evaluate the clinical efficacy of iodine-123-MIBG SPECT as a noninvasive screening test in patients with coronary artery spasm. METHOD: Coronary arteriography and provocative test with intravenous administration of ergonovine maleate were performed in 26 patients (21 men, 5 women, mean age 49.1+/-9.3, range: 26-59) who were suspected of having a coronary artery spasm. The subjects were divided into 2 groups ; Group 1 comparised of 18 patients subjects to the positive provocative test, Group 2 comparised of 8 patients subjects to the negative provocative test. Four healthy subjects served as control. All patients also underwent iodine-123-MIBG SPECT for the evaluation of cardiac sympathetic integrity. The SPECT findings were qualitatively evaluated by two experienced physicians who were blind to the clinical data. RESULTS: Abnormal sympathetic nervous innervation using iodine-123-MIBG SPECT was observed either as a reduced uptake or defect pattern in the perfused areas in 13 of the 18 vessels of ergonovine induced vasospasm. Normal sympathetic innervation as evidenced by normal iodine-123-MIBG uptake was noted in all of the 60 segments of normal vessel territories. Reduced uptake of iodine-123-MIBG was not detected in the perfused areas of five vasospasm-induced vessels (perfusion territory of LAD in 2 and the RCA in 3 patients). The sensitivity and specificity of iodine-123-MIBG for detection coronary artery spasm were 72.2% (95% confidence interval [CI] 55% to 89%) and 100%, respectively. The positive predictive value and negative predictive value were 100% and 92.3% (95% CI 91% to 93%), respectively. CONCLUSION: Iodine-123-MIBG SPECT is a feasible method to noninvasively evaluate and localize the territories of coronary arteries with spasms. Invasive diagnostic coronary arteriography with ergonovine provocation test may be unnecessary for the diagnosis of coronary artery spasm in patients with typical resting pain, negative exercise test or normal thallium perfusion scan, but abnormal iodine-123-MIBG SPECT.

Diagnostic Efficacy of Biochemical Studies and MIBG Scan in Pheochromocytoma / 대한비뇨기과학회지

We evaluated the role of clinical symptoms, biochemical studies and metaiodobenzylguanidine (MIBG) scan in the diagnosis of pheochromocytoma. From August 1991 to June 1997, 42 patients with complaints of hypertension or adrenal mass were evaluated with MIBG scan, 24 hour urinary vanillylmandelic acid (VMA), serum and 24 hour urinary catecholamine and radiologic studies such as CT, MRI or ultrasonography. Initial 9 patients were evaluated with 131 I-MIBG scan and the rest 33 patients with 123 I-MIBG scan. Of 42 patients, histologic diagnosis was obtained in 32 patients including 23 patients with pheochromocytoma or paraganglioma and 9 patients with other adrenal or extra-adrenal tumors. Remaining 10 patients had no evidence of adrenal disease on radiologic studies. Paroxysmal symptoms or hypertension was noted in 14 patients with pheochromocytoma or paraganglioma, while it was also found in 12 out of 19 patients without pheochromocytoma or paraganglioma. Sensitivity, specificity and positive predictive value (PPV) of each diagnostic modality were 60.9%, 92.9% and 93.3% in 24 hour urinary VMA, 61.9%, 75.0%, and 81.3% in 24 hour urinary catecholamine, 82.6%, 94.7%, and 95.0% in MIBG scan, respectively. Sensitivity and specificity were improved to 86.9% and 100% when 24 hour urinary VMA and MIBG scan were combined. In conclusion, MIBG scan was the most useful single screening method for the diagnosis of pheochromocytoma, and combination of MIBG scan and 24 hour urinary VMA would enhance the diagnostic accuracy.

Iodine-123-Metaiodobenzylguanidine Myocardial Scintigraphy in Patients with Dilated Cardiomyopathy : Correlation between Myocardial MIBG Uptake and Echocardiographic Parameters

BACKGROUND: The prognosis of patients with dilated cardiomyopathy remains poor. Doppler echocardiography and cardiac iodine-123-metaiodobenzylguanidine(MIBG) myocardial scintigraphy are useful non-invasive diagnostic modalities to assess the prognosis in these patients. However, the relationship between myocardial MIBG uptake and Doppler echocardiographic. variables was not well investigated. We analyzed the cardiac MIBG imaging in 40 patients with dilated cardiomyopathy and assessed the correlation between the echocardiographic parameters and myocardial MIBG uptake. MIBG uptake(DHM), assessed as the heart/mediastinum ratio measured on anterior view image obtained 4 hours after injection, was compared with M-mode(left ventricular end-diastolic dimension, left ventricular ejection fraction) and Doppler parameters. RESULTS: 1) Early and delayed MIBG uptake of heart were significantly lower in patient group compared with normal control subjects. There were no significant differences in lung and mediastinum uptake of MIBG between the two groups. 2) Early and delayed MIBG uptake ratios of the heart to lung and heart to mediastinum were significantly lower in patient group compared with those of normal control subjects. 3) DHM was significantly lower in patients with NYHA functional class 3, 4 than those with NYHA functional class 1, 2 in patient group. There was, however, no significant difference of DHM in patient group divided by the degree of mitral regurgitation and left ventricular diastolic filling pattern. 4) There were no significant correlations between DHM and other prognostic factors(left ventricular end-diastolic dimension, left ventricular ejection fraction, peak velocity of early diastolic filling(E velocity), deceleration time of E wave, cardiac output, pulmonary capillary wedge pressure, left ventricular end-diastolic pressure and 24hr urine norepinephrine). CONCLUSION: Iodine-123-MIBG scan is a useful noninvasive imaging modality in the assessment of cardiac sympathetic neuronal integrity in patients with dilated cardiomyopathy. There were no significant correlations between cardiac MIBG uptake and other prognostic factors. The cardiac MIBG uptake probably can be utilized as an independent prognostic factor, hence it would be suggested that a large prospective clinical study is needed to consolidate these findings.