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A 50-year-old woman was diagnosed with iron deficiency anemia on general medical examination. Further, contrast-enhanced abdominal CT and magnetic resonance imaging revealed a large hypervascular mass with internal degeneration and necrosis in the retroperitoneal space. She was referred to our hospital for further evaluation and treatment. Because the paraganglioma was most likely as the imaging diagnosis, 123I-MIBG scintigraphy was performed. It revealed the marked abnormal accumulation in the retroperitoneal lesion indicating the paraganglioma and no other abnormal accumulation was noted. Several plasma catecholamines and their urinary metabolites were normal. On the subsequent 18F-FDG PET/CT, high FDG uptake was found in the retroperitoneal lesion (SUVmax=38). FDG uptake was also found in a small nodule at the base of the lower lobe of the right lung (SUVmax= 9.8). Contrast-enhanced imaging revealed a hypervascular nodule at the base of the right lung, suggesting pulmonary metastasis of a paraganglioma. The abdominal lesion and right lung nodule were excised, and retroperitoneal paraganglioma and pulmonary metastasis were diagnosed based on the pathology findings. In this case, 18F-FDG PET/CT was useful in the search for paraganglioma metastasis. We report a relationship between 123I-MIBG accumulation and 18F-FDG uptake in paraganglioma and review the relevant literature.

A 50-year-old woman was diagnosed with iron deficiency anemia on general medical examination. Further, contrast-enhanced abdominal CT and magnetic resonance imaging revealed a large hypervascular mass with internal degeneration and necrosis in the retroperitoneal space. She was referred to our hospital for further evaluation and treatment. Because the paraganglioma was most likely as the imaging diagnosis, 123I-MIBG scintigraphy was performed. It revealed the marked abnormal accumulation in the retroperitoneal lesion indicating the paraganglioma and no other abnormal accumulation was noted. Several plasma catecholamines and their urinary metabolites were normal. On the subsequent 18FFDG PET/CT, high FDG uptake was found in the retroperitoneal lesion (SUVmax=38). FDG uptake was also found in a small nodule at the base of the lower lobe of the right lung (SUVmax= 9.8). Contrast-enhanced imaging revealed a hypervascular nodule at the base of the right lung, suggesting pulmonary metastasis of a paraganglioma. The abdominal lesion and right lung nodule were excised, and retroperitoneal paraganglioma and pulmonary metastasis were diagnosed based on the pathology findings. In this case, 18F-FDG PET/CT was useful in the search for paraganglioma metastasis. We report a relationship between 123I-MIBG accumulation and 18F-FDG uptake in paraganglioma and review the relevant literature. [ABSTRACT FROM AUTHOR]

Introduction: In the risk stratification and selection of patients with heart failure (HF) eligible for implantable cardioverter‐defibrillator (ICD) therapy, 123I‐meta‐IodineBenzylGuanidine (123I‐mIBG) scintigraphy has emerged as an effective non‐invasive method to assess cardiac adrenergic innervation. Similarly, clinical risk scores have been proposed to identify patients with HF at risk of all‐cause mortality, for whom the net clinical benefit of device implantation would presumably be lower. Nevertheless, the association between the two classes of tools, one suggestive of arrhythmic risk, the other of all‐cause mortality, needs further investigation. Objective: To test the relationship between the risk scores for predicting mortality and cardiac sympathetic innervation, assessed through myocardial 123I‐mIBG imaging, in a population of patients with HF. Methods: In HF patients undergoing 123I‐mIBG scintigraphy, eight risk stratification models were assessed: AAACC, FADES, MADIT, MADIT‐ICD non‐arrhythmic mortality score, PACE, Parkash, SHOCKED and Sjoblom. Cardiac adrenergic impairment was assessed by late heart‐to‐mediastinum ratio (H/M) <1.6. Results: Among 269 patients suffering from HF, late H/M showed significant negative correlation with all the predicting models, although generally weak, ranging from −0.15 (p =.013) for PACE to −0.32 (p <.001) for FADES. The scores showed poor discrimination for cardiac innervation, with areas under the curve (AUC) ranging from 0.546 for Parkash to 0.621 for FADES. Conclusion: A weak association emerged among mortality risk scores and cardiac innervation, suggesting to integrate in clinical practice tools indicative of both arrhythmic and general mortality risks, when evaluating patients affected by HF eligible for device implantation. [ABSTRACT FROM AUTHOR]

Previous reports have found evidence that the lung uptake of iodine-123-metaiodobenzylguanidine (123I-MIBG) represents pulmonary vascular endothelial function. Therefore, it was believed that the reduced lung uptake of 123I-MIBG in patients with pulmonary artery hypertension may indicate poor pulmonary vascular endothelial function in those patients. In our previous report, we analyzed the lung uptake of 123I-MIBG in patients with pulmonary hypertension, and demonstrated that it is lower in patients with pulmonary arterial hypertension (PAH) than in those with chronic thromboembolic pulmonary hypertension and controls, suggesting that reduced uptake of 123I-MIBG in patients with PAH indicates endothelial dysfunction of the pulmonary artery. In the current report, we describe a 46-year-old woman diagnosed with scleroderma whose lung uptake of 123I-MIBG was decreased on admission, but she was not diagnosed with pulmonary artery hypertension at that time because her pulmonary artery pressure during right heart catheterization was not elevated. However, she was diagnosed with borderline PAH 2 years later. The lung uptake of 123I-MIBG was reduced before a reduction in %DLCO was observed. This report suggests that the lung uptake of 123I-MIBG may be useful for the early diagnosis of pulmonary artery hypertension.

Abstract Takotsubo syndrome (TTS), also referred to as stress cardiomyopathy, is characterized by transient left ventricular apical ballooning in the absence of obstructive coronary artery disease. Catecholamine‐induced cardiac injury or vasospasm has been implicated in this pathophysiology. We present a case of a 67‐year‐old man 10 years after heart transplantation diagnosed with TTS. Sympathetic reinnervation could not be detected by iodine‐123 meta iodobenzylguanidine uptake, suggesting that TTS can occur in the absence of functional sympathetic nerve systems reconstruction.

Purpose: Planar scintigraphy with 123I-radiolabeled metaiodobenzylguanidine (123I-mIBG) is an important imaging modality to evaluate neuroblastoma. In recent years, Single Photon Emission Computed Tomography combined with Computed Tomography (SPECT/CT) has revolutionized nuclear medicine. Nevertheless, the addition of the CT has increased the patients' irradiation. We aimed to evaluate the incremental benefits of 123I-mIBG SPECT/CT over conventional planar imaging and to estimate the relative increase of radiation dose. Methods: We retrospectively evaluated the added value of 56 SPECT/CT performed in 40 children in terms of better characterization of the lesion and its locoregional extension, better lymph node staging, detection of new lesions, and elimination of false positives by a paired comparison between the planar images and the SPECT/CT ones. Then, we calculated the percentage contribution of the additional radiation of the CT in this hybrid imagery. Results: In 88% (49 out of 56) of the examinations, SPECT/CT provided additional information, which was crucial in 20% of the cases. It allowed a better characterization of the lesion and its locoregional extension in 44 cases, a better lymph node staging in 28 cases, the detection of 33 new lesions, and the elimination of 9 false positives. The CT effective dose was significantly lower than the SPECT one. The average additional radiation exposure due to CT was 12% (4–23%). Conclusion: 123I-mIBG SPECT/CT has an undeniable added value that improves planar imaging interpretation and impacts patient management. These potential benefits would justify the low additional radiation induced by the CT. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the detecting capability between planar imaging (PI) and PI combined with single-photon emission computed tomography/computed tomography (PICWS), including 123I- and 131I-labeled metaiodobenzylguanidine (mIBG) and to compare the detecting capability between 123I-mIBG and post-therapeutic 131I-mIBG scintigraphy including PI and PICWS for Curie scoring in patients with neuroblastoma.Methods: Sixty-two patients with 66 pairs of complete images with neuroblastoma were enrolled in this retrospective study.Results: Comparing the Curie scoring between 123I-mIBG PI and PICWS and between post-therapeutic 131I-mIBG PI and PICWS, findings were concordantly negative in 28.79% and 18.18% of studies, concordantly positive in 66.67% and 74.24% of studies, and discordant in 4.54% and 7.58% of studies, respectively. PICWS was superior to PI including 123I- and 131I-mIBG in the evaluation of Curie scoring for neuroblastoma patients (both P < 0.001). Comparing the Curie scores between 123I- and post-therapeutic 131I-mIBG PI and between 123I- and post-therapeutic 131I-mIBG PICWS, concordantly negative imaging was visualized in 22.73% and 19.70% of studies, concordantly positive imaging in 66.67% and 69.70% of studies, and discordant imaging in 10.60% and 10.60% of studies, respectively. Post-therapeutic 131I-mIBG was significantly better than that of 123I-mIBG scintigraphy including PI and PICWS in detecting the Curie scoring for neuroblastoma patients (both P < 0.001).Conclusion: The present study demonstrates that 131I- or 123I-mIBG PICWS are more helpful in the evaluation of Curie scores than that of conventional PI and that post-therapeutic 131I-mIBG is superior to 123I-mIBG scintigraphy for the detecting capability of Curie scoring in patients with neuroblastoma. [ABSTRACT FROM AUTHOR]

Purpose of Review: This narrative review reflects on the body of evidence on cardiac 123I-mIBG imaging that has accumulated since the introduction in the late 1970s and focusses on to what extent cardiac 123I-mIBG imaging has fulfilled its potential in cardiology especially. Recent Findings: In contrast to the linear relationship between 123I-mIBG-derived parameters and overall prognosis in heart failure, there seems a "bell-shape" curve for 123I-mIBG-derived parameters and arrhythmic events. In addition, there is a potential clinical role for cardiac 123I-mIBG in optimizing patient selection for expensive devices (i.e., ICD and CRT). This needs of course to be established in future trials. Summary: Cardiac 123I-mIBG imaging is, despite the numerous of studies, sometimes mistakenly seen as a nice to have technique rather than a must have imaging modality. Although cardiac 123I-mIBG imaging has grown and matured over the years, its full clinical potential has still not been tested to the maximum. [ABSTRACT FROM AUTHOR]

Cardiac sympathetic upregulation is one of the neurohormonal compensation mechanisms that play an important role in the pathogenesis of chronic heart failure (CHF). In the past decades, cardiac 123I-mIBG scintigraphy has been established as a feasible technique to evaluate the global and regional cardiac sympathetic innervation. Although cardiac 123I-mIBG imaging has been studied in many cardiac and neurological diseases, it has extensively been studied in ischemic and non-ischemic CHF. Therefore, this review will focus on the role of 123I-mIBG imaging in CHF. This non-invasive, widely available technique has been established to evaluate the prognosis in CHF. Standardization, especially among various combinations of gamma camera and collimator, is important for identifying appropriate thresholds for adequate risk stratification. Interestingly, in contrast to the linear relationship between 123I-mIBG-derived parameters and overall prognosis, there seems to be a “bell-shape” curve for 123I-mIBG-derived parameters in relation to ventricular arrhythmia or appropriate implantable cardioverter defibrillator (ICD) therapy in patients with ischemic CHF. In addition, there is a potential clinical role for cardiac 123I-mIBG imaging in optimizing patient selection for implantation of expensive devices such as ICD and cardiac resynchronization therapy (CRT). Based on cardiac 123I-mIBG data risk models and machine learning, models have been developed for appropriate risk assessment in CHF.

Takotsubo syndrome (TTS), also referred to as stress cardiomyopathy, is characterized by transient left ventricular apical ballooning in the absence of obstructive coronary artery disease. Catecholamine‐induced cardiac injury or vasospasm has been implicated in this pathophysiology. We present a case of a 67‐year‐old man 10 years after heart transplantation diagnosed with TTS. Sympathetic reinnervation could not be detected by iodine‐123 meta iodobenzylguanidine uptake, suggesting that TTS can occur in the absence of functional sympathetic nerve systems reconstruction. [ABSTRACT FROM AUTHOR]

Background: Despite therapeutic improvement, the prognosis of chronic heart failure (CHF) remains unfavorable partly due to arrhythmia and sudden cardiac death (SCD). This prospective study evaluated myocardial 123I-meta-iodobenzylguanidine (123I-mIBG) scintigraphy as a predictor of arrhythmic events (AE) in CHF patients.Methods: 170 CHF patients referred for implantable cardioverter-defibrillator (ICD) implantation for both primary and secondary prevention were enrolled. All patients underwent planar and SPECT imaging. Early and late heart-to-mediastinum (H/M) ratio, 123I-mIBG washout (WO), early and late summed SPECT scores were calculated The primary endpoint was an AE: sustained ventricular tachycardia, resuscitated cardiac arrest, appropriate ICD therapy or SCD. The secondary endpoint was appropriate ICD therapy.Results: During a median follow-up of 23.3 months, 69 patients experienced an AE. Early summed score (ESS) was the only independent predictor of AE [HR 1.023 (1.003-1.043)]. Focussing on only patients with an ICD for primary prevention, ESS was the only independent predictor of AE [HR 1.028 (1.007-1.050)]. 123I-mIBG-derived parameters failed to be independent predictors of appropriate ICD therapy. However there was a "bell-shaped" relation between 123I-mIBG scintigraphy-derived parameters and AE and appropriate ICD therapy, i.e., those with intermediate 123I-mIBG abnormalities tended to be at higher risk of events.Conclusion: Although SPECT 123I-mIBG scintigraphy was associated with AE in CHF patients with ICD implantation for primary and secondary prevention, no association was found between 123I-mIBG scintigraphy-derived parameters and appropriate ICD therapy. [ABSTRACT FROM AUTHOR]

The management of idiopathic dilated cardiomyopathy (DCM) is well established. However, a subset of patients do not have recovery from or have recurrences of left ventricular (LV) dysfunction despite receiving optimal medical therapy. There are limited long-term follow-up data about LV function and the predictive value of iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy, especially among the Japanese population. We retrospectively investigated 81 consecutive patients with DCM (mean LV ejection fraction (EF) 28 ± 7.5%) who had undergone 123I-MIBG scintigraphy before starting β-blockers. According to chronological changes in LVEF, study patients were classified into three subgroups: sustained recovery group, recurrence group, and non-recovery group. The outcome measure was cardiac death. Mean age was 59 ± 11 years and median follow-up was 11.5 (5.8-15.0) years. Thirty-six patients had recovery, 11 had recurrences, and 34 did not have recovery. The sustained recovery group had the best cardiac death-free survival, followed by the recurrence and non-recovery groups. Prolonged time to initial recovery was associated with recurrence of LV dysfunction. Large LV end-diastolic diameter and reduced heart to mediastinum ratio were associated with poor prognosis. In conclusion, with β-blocker therapy, 14% of patients showed recurrences of LV dysfunction. Thus, careful follow-up is needed, keeping in mind the possibility of recurrence, even if LVEF once improved, especially in patients whose time to initial recovery was long. 123I-MIBG scintigraphy provides clinicians with additional prognostic information. [ABSTRACT FROM AUTHOR]

Increased sympathetic activity is suggested to be part of the pathogenesis in several diseases. Methods to evaluate sympathetic activity and renal nervous denervation procedural success are lacking. Scintigraphy using the norepinephrine analog Iodine-123 Metaiodobenzylguanidine (123I-MIBG) might provide information on renal sympathetic nervous activity. Renal transplantation induces complete denervation of the kidney and as such represents an ideal model to evaluate the renal 123I-MIBG scintigraphy method. The aim of this study was to evaluate whether renal 123I-MIBG scintigraphy can detect changes in renal sympathetic nervous activity following renal transplantation. Renal 123I-MIBG scintigraphy was performed in eleven renal transplant recipients at 1, 3, and 6 months following transplantation and in their respective living donors prior to their kidney donation. Relative uptake as well as washout was obtained. In transplanted patients, the relative 4 h uptake of 123I-MIBG, as measured by the kidney/background ratio, was 2.7 (0.4) (mean (SD)), 2.7 (0.5), and 2.5 (0.4) at 1, 3, and 6 months post-transplantation, respectively, as compared with the 4.0 (0.4) value in the donor kidney before donor nephrectomy (p < 0.01). There was no significant change in washout-rate between pre-transplantation and any of the follow-up time points. Living donor kidney transplantation was at 6 months post transplantation, associated with an almost 40% reduction in the relative 4 h 123I-MIBG uptake of the kidney. Further studies will help to fully establish its implications as a marker of renal innervation or denervation.

Aim: Planar myocardial 123I-meta-iodobenzylguanidine (123I-mIBG) scintigraphy is a highly reproducible technique. However, differences in collimator use are one of the most important factors that cause variation among institutions and studies in heart-to-mediastinum (H/M) ratio. Therefore, standardization among various gamma camera-collimator combinations is needed. Previously, a phantom has been developed to cross-calibrate different acquisition conditions in Japan. For further cross-calibration of European myocardial 123I-mIBG imaging, the aim of this study was to collect 123I-mIBG data for H/M ratios from common European gamma camera vendors.Methods: 210 experiments were performed in 27 European institutions. Based on these experiments, conversion coefficients for each gamma camera-collimator combination were calculated. An averaged conversion coefficient of 0.88 was used to calculate a standardized H/M ratio.Results: On average, LE-collimator-derived H/M ratios were significantly lower compared to ME-collimator-derived H/M ratios. The mean conversion coefficients ranged from 0.553 to 0.605 for the LE-collimator group and from 0.824 to 0.895 for the ME-collimator group.Conclusion: Clinically established H/M ratios can be converted into standardized H/M ratios using cross-calibrated conversion coefficients. This standardization is important for identifying appropriate thresholds for adequate risk stratification. In addition, this cross-calibration enables comparison between different national and international data. [ABSTRACT FROM AUTHOR]

Background 123I-meta-iodobenzylguanidine (123I-MIBG) myocardial scintigraphy is considered reliable in differentiating idiopathic Parkinson's disease (IPD) from other parkinsonisms, but it is biased by pharmacological treatments. Skin biopsy is not influenced by therapy and has disclosed skin denervation in IPD. Our aims were to compare 123I-MIBG scintigraphy and skin biopsy findings in IPD and parkinsonisms to (1) verify whether myocardial and skin denervations are linked; (2) explore the simultaneous extent of the autonomic dysfunction. Methods We studied 22 IPD and 11 parkinsonism patients by means of 123I-MIBG scintigraphy and skin biopsies. Results In the IPD group, both 123I-MIBG scintigraphy and skin biopsy results were abnormal in 91% of patients, showing concordance in 82% of cases. In parkinsonisms, results of both tests were normal in all patients. Conclusion (1) Skin biopsy and 123I-MIBG scintigraphy provide comparable results; (2) in IPD, autonomic dysfunctions are often simultaneously widespread at cardiac and skin branches. © 2015 International Parkinson and Movement Disorder Society [ABSTRACT FROM AUTHOR]

Background: The carotid sinus baroreceptor reflex controls the neural regulation of blood pressure. Baroreceptor disorders due to carotid sinus atherosclerosis have detrimental cardiovascular effects. This study investigated the medium-term effects of carotid artery revascularization (CAR) on sympathetic and cardiac function and systemic blood pressure variability in patients with carotid artery stenosis., Methods: This study included 21 consecutive patients (median age 70 years, 18 men) with carotid artery stenosis scheduled for CAR. 123 I metaiodobenzylguanidine (MIBG) scintigraphy, echocardiography, brain natriuretic peptide levels, 24-h Holter electrocardiography (ECG), and ambulatory blood pressure monitoring assessed approximately 3 months postoperatively were compared to preoperative data., Results: All 21 enrolled patients underwent CAR. Carotid artery stenting was done in three patients with cardiovascular risk or anatomical difficult for carotid endarterectomy. The mean common carotid artery end-diastolic velocity improved significantly (P < 0.01) by 1.6-fold, from 10.8 ± 3.2 to 16.1 ± 7.1 cm/s. In 123 I-MIBG scintigraphy, the heart-to-mediastinum (H/M) count ratio was significantly higher than preoperatively (from 2.66 ± 0.48 to 2.86 ± 0.56, P = 0.03). Holter ECG analysis revealed a significant decrease in the low-frequency/high-frequency (LF/HF) ratio compared to preoperatively (from 2.17 ± 1.20 to 1.62 ± 0.68, P = 0.04). These findings suggest decreased myocardial sympathetic activation. In echocardiography, the tissue Doppler-derived e' increased, and E/e' decreased significantly (P < 0.05) from 11.7 ± 5.1 to 10.1 ± 4.0, suggesting an improved left ventricular diastolic capacity. The mean 24-h and nighttime blood pressures were unchanged., Conclusions: CAR in patients with carotid stenosis may provide medium-term improvement in cardiac sympathetic nerve activity and left ventricular diastolic dysfunction., Competing Interests: The authors declare that they have no conflict of interest., (Copyright 2022, Kato et al.)

Aims: Cardiac 123iodine-meta-iodobenzylguanidine (123I-mIBG) single-photon emission computed tomography (SPECT) imaging provides information on regional myocardial innervation. However, the value of the commonly used 17-segment summed defect score (SDS) as a prognostic marker is uncertain. The present study examined whether a simpler regional scoring approach for evaluation of 123I-mIBG SPECT combined with rest 99mTc-tetrofosmin SPECT myocardial perfusion imaging could improve prediction of arrhythmic events (AEs) in patients with ischaemic heart failure (HF)., Methods and Results: Five hundred and two ischaemic HF subjects of the ADMIRE-HF study with complete cardiac 123I-mIBG and rest 99mTc-tetrofosmin SPECT studies were included. Both SPECT image sets were read together by two experienced nuclear imagers and scored by consensus. In addition to standard 17-segment scoring, the readers classified walls (i.e. anterior, lateral, inferior, septum and apex) as normal, matched defect, mismatched (innervation defect > perfusion defect), or reverse mismatched (perfusion defect > innervation defect). Cox proportional hazards ratios (HRs) were used to determine if age, body mass index, functional class, left ventricular ejection fraction (LVEF), B-type natriuretic peptide (BNP), norepinephrine, 123I-mIBG SDS, 99mTc-tetrofosmin SDS, innervation/perfusion mismatch SDS, and our simplified visual innervation/perfusion wall classification were associated with occurrence of AEs (i.e. sudden cardiac death, sustained ventricular tachycardia, resuscitated cardiac arrest, appropriate implantable cardioverter-defibrillator therapy). At 2-year median follow-up, 52 subjects (10.4%) had AEs. Subjects with 1 or 2 mismatched walls were twice as likely to have AEs compared with subjects with either 0 or 3-5 mismatched walls (16.3% vs. 8.3%, P = 0.010). Cox regression analyses showed that patients with a visual mismatch in 1-2 walls had an almost two times higher risk of AEs [HR 2.084 (1.109-3.914), P = 0.001]. None of the other innervation, perfusion and mismatch scores using standard 17 segments were associated with AEs. BNP (ng/L) was the only non-imaging parameter associated with AEs., Conclusion: A visual left ventricular wall-level based scoring method identified highest AE risk in ischaemic HF subjects with intermediate levels of innervation/perfusion mismatches. This simple technique for the evaluation of SPECT studies, which are often challenging in HF subjects, seems to be superior to the 17-segment scoring method., Competing Interests: Conflict of interest: A.F.J. was an employee at GE Healthcare during the conduct of the original ADMIRE-HF study. The other authors declare that they have no conflict of interest., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Cardiac sympathetic upregulation is one of the neurohormonal compensation mechanisms that play an important role in the pathogenesis of chronic heart failure (CHF). In the past decades, cardiac 123 I- m IBG scintigraphy has been established as a feasible technique to evaluate the global and regional cardiac sympathetic innervation. Although cardiac 123 I- m IBG imaging has been studied in many cardiac and neurological diseases, it has extensively been studied in ischemic and non-ischemic CHF. Therefore, this review will focus on the role of 123 I- m IBG imaging in CHF. This non-invasive, widely available technique has been established to evaluate the prognosis in CHF. Standardization, especially among various combinations of gamma camera and collimator, is important for identifying appropriate thresholds for adequate risk stratification. Interestingly, in contrast to the linear relationship between 123 I- m IBG-derived parameters and overall prognosis, there seems to be a "bell-shape" curve for 123 I- m IBG-derived parameters in relation to ventricular arrhythmia or appropriate implantable cardioverter defibrillator (ICD) therapy in patients with ischemic CHF. In addition, there is a potential clinical role for cardiac 123 I- m IBG imaging in optimizing patient selection for implantation of expensive devices such as ICD and cardiac resynchronization therapy (CRT). Based on cardiac 123 I- m IBG data risk models and machine learning, models have been developed for appropriate risk assessment in CHF.

Purpose: To analyse different uptake patterns in I-MIBG scintigraphy/SPECT imaging and F-FDG PET in paediatric neuroblastoma patients. Methods: We compared 23 I-MIBG scintigraphy scans and 23 F-FDG PET scans (mean interval 10 days) in 19 patients with a suspected neuroblastic tumour (16 neuroblastoma, 1 ganglioneuroblastoma, 1 ganglioneuroma and 1 opsomyoclonus syndrome). SPECT images of the abdomen or other tumour-affected regions were available in all patients. Indications for F-FDG PET were a I-MIBG-negative tumour, a discrepancy in I-MIBG uptake compared to the morphological imaging or imaging results inconsistent with clinical findings. A lesion was found by I-MIBG scintigraphy and/or F-FDG PET and/or morphological imaging. Results: A total of 58 suspicious lesions (mean lesion diameter 3.8 cm) were evaluated and 18 were confirmed by histology and 40 by clinical follow-up. The sensitivities of I-MIBG scintigraphy and F-FDG PET were 50% and 78% and the specificities were 75% and 92%, respectively. False-positive results (three I-MIBG scintigraphy, one F-FDG PET) were due to physiological uptake or posttherapy changes. False-negative results (23 I-MIBG scintigraphy, 10 F-FDG PET) were due to low uptake and small lesion size. Combined I-MIBG scintigraphy/F-FDG PET imaging showed the highest sensitivity of 85%. In 34 lesions the I-MIBG scintigraphy and morphological imaging findings were discrepant. F-FDG PET correctly identified 32 of the discrepant findings. Two bone/bone marrow metastases were missed by F-FDG PET. Conclusion: I-MIBG scintigraphy and F-FDG PET showed noticeable differences in their uptake patterns. F-FDG PET was more sensitive and specific for the detection of neuroblastoma lesions. Our findings suggest that a F-FDG PET scan may be useful in the event of discrepant or inconclusive findings on I-MIBG scintigraphy/SPECT and morphological imaging. [ABSTRACT FROM AUTHOR]

Aims Loop diuretics are essential for the treatment of chronic heart failure (CHF) but short-acting diuretics are reported to induce sympathetic nervous system (SNS) activation. This study was performed to compare therapeutic effects of two loop diuretics, long-acting azosemide and short-acting furosemide, using 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy. Methods and results Twenty-two patients with New York Heart Association class II–III heart failure and left ventricular dysfunction, who required treatment with a loop diuretic, were included. In this crossover study, 11 patients were randomized to azosemide treatment first and the remaining 11 patients to furosemide. Treatments were administered for 6 months and then patients were crossed over to the second treatment. 123I-MIBG scintigraphy was performed before and 6 months after the start of treatment with each loop diuretic. Early and delayed images were obtained 20 min and 4 h after administration of 123I-MIBG, respectively; and the heart/mediastinum (H/M) ratio and washout rate (WR) were measured. In addition, left ventricular ejection fraction (LVEF), levels of brain natriuretic peptide (BNP), and norepinephrine were measured before and 6 months after the start of treatment. No differences were observed between the two groups in terms of concomitant medication, cause of heart failure, H/M ratio, WR, BNP, norepinephrine, or LVEF. The azosemide group exhibited a significant increase in delayed image H/M ratio, and a significant decrease in WR and norepinephrine after the final administration compared with the furosemide group. Conclusion This study indicates that azosemide suppresses SNS activation compared with furosemide in patients with CHF, suggesting that long-acting loop diuretics may have more beneficial effects on the prognosis of CHF. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the prevalence of cardiac autonomic neuropathy (CAN) in a cohort of patients with type 2 diabetes, truly asymptomatic for coronary artery disease (CAD), using heart rate variability (HRV) and 123I-metaiodobenzylguanidine (123I- mIBG) myocardial scintigraphy. The study group comprised 88 patients with type 2 diabetes prospectively recruited from an outpatient diabetes clinic. In all patients myocardial perfusion scintigraphy, CAN by HRV and 123I- mIBG myocardial scintigraphy were performed. Two or more abnormal tests were defined as CAN-positive (ECG-based CAN) and one or fewer as CAN-negative. CAN assessed by 123I- mIBG scintigraphy was defined as abnormal if the heart-to-mediastinum ratio was <1.8, the washout rate was >25%, or the total defect score was >13. The prevalence of CAN in patients asymptomatic for CAD with type 2 diabetes and normal myocardial perfusion assessed by HRV and 123I- mIBG scintigraphy was respectively, 27% and 58%. Furthermore, in almost half of patients with normal HRV, 123I- mIBG scintigraphy showed CAN. The current study revealed a high prevalence of CAN in patients with type 2 diabetes. Secondly, disagreement between HRV and 123I- mIBG scintigraphy for the assessment of CAN was observed. [ABSTRACT FROM AUTHOR]

Aim: The aim of the study was to evaluate the current role of 123I-MIBG scintigraphy in the detection and follow-up of patients with paragangliomas. Materials and Methods: 117 patients were referred for diagnostic 123I-MIBG scintigraphy based on a strong clinical suspicion, positive familial history and genetic testing, or for follow-up of paragangliomas.123I-MIBG images were analyzed and correlated with 111In-octreotide scintigraphy, CT or MRI results. Accuracy of the imaging method was calculated per patient and per tumor per site. Results: A total of 117 patients were referred for 123I-MIBG diagnostic imaging; 80 patients were diagnosed with paraganglioma; 66 patients had a single neuroendocrine tumor and 14 patients multiple tumors. The total number of all lesions in these patients was 172. 123I-MIBG scintigraphy demonstrated 65 lesions in 56 patients (overall sensitivity: 56.3%, specificity: 84%). Lesion-per-site analysis revealed that sensitivity and specificity significantly varied per tumor site (lowest sensitivity for the head and neck: 17.5% and lowest specificity for the abdomen: 87.5%). Hormones were elevated in 85 patients: 55 123I-MIBG tumors were positive and 35 tumors were negative. In 16 patients (13.7%) with a genetic burden and a single neuroendocrine tumor, 123I-MIBG whole-body imaging was successful at detecting a second tumor. In 2 patients (1.7%) with paragangliomas, 123I-MIBG unexpectedly detected metastases, so the restaging was properly done. Conclusion:123I-MIBG scintigraphy remains important in pheochromocytoma and functioning neuroendocrine tumors. The value of 123I-MIBG scintigraphy is high in familial syndromes with multiple neuroendocrine tumors at different sites, multifocal tumors, and relapsing and metastatic disease. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Aim/Purpose: 123I-meta-iodobenzylguanidine (123I-mIBG) scintigraphy is well established for staging and evaluation of response in children with high-risk neuroblastoma but its prognostic value in highly intensive first-line treatment protocols is uncertain. The presence of any 123I-mIBG positive tumour tissue was correlated with event-free survival (EFS) and overall survival (OS). Patients and methods: The prognostic impact of residual 123I-mIBG uptake into the primary tumour and metastases for predicting outcome in 113 stage 4 neuroblastoma patients >1 year of the German Neuroblastoma Trial NB97 was assessed using a univariate log-rank test and multivariate Cox regression analysis. Results: All patients had 123I-mIBG positive disease at initial staging. After four courses of induction chemotherapy, 71% of patients were still 123I-mIBG positive for the primary tumour and 61% for metastases. After six courses, 39% of patients had 123I-mIBG uptake by the primary tumour and 45% residual 123I-mIBG positive metastatic disease. The 123I-mIBG status of the primary tumour site had no bearing on outcome. Residual 123I-mIBG positive metastatic disease after four (3-y-EFS 25.7±5.3% versus 55.9±7.6%, p =0.009; 3-y-OS 49.8±6.1% versus 65.0±7.3%; p =0.021) and after six chemotherapy cycles (3-y-EFS 27.5±6.2% versus 47.4±6.4%, p =0.011; 3-y-OS 50.5±7.1% vs 60.0±6.4%, p =0.031) was associated with poor outcome. Conclusion: Functional imaging with 123I-mIBG scintigraphy can identify poor responders with any persistent metastatic 123I-mIBG uptake who are at a high risk of disease relapse. 123I-mIBG response of the primary tumour site had no bearing on outcome. [Copyright &y& Elsevier]

Abstract: Objective: We estimated the extent and pattern of cardiovascular autonomic dysfunction in dementia with Lewy bodies (DLB) as compared with that in Parkinson''s disease (PD). Methods: We performed meta-iodobenzylguanidine (123I-MIBG) scintigraphy of the heart and hemodynamic autonomic function testing using the Valsalva maneuver in 27 patients with DLB, 46 with PD, and 20 controls. Results: 123I-MIBG uptakes in DLB were reduced as compared with those in control and PD. Hemodynamic studies revealed that DLB had decreased baroreceptor reflex and reduced responses of SBP in phases II and IV as compared with PD and control. SBP responses on standing and the difference in plasma norepinephrine (NE) concentrations between supine and standing positions were reduced in PD as compared with those in control. Furthermore, SBP responses on standing, plasma NE concentrations in supine and standing positions, and the difference in plasma NE concentrations between these positions were significantly lower in DLB than in PD and control. Plasma NE concentrations in DLB with orthostatic hypotension (OH) were lower than that in DLB without OH, although some patients who had DLB with orthostatic hypotension had relatively normal plasma NE levels. Conclusion: Cardiovascular autonomic dysfunction is more severe in DLB than in PD and is usually caused by the loss of postganglionic sympathetic nervous function, although dysautonomia in some patients with DLB may result from preganglionic dysfunction. [Copyright &y& Elsevier]

It is likely that a close association exists between findings obtained by two methods: dobutamine stress echocardiography and 123I-MIBG scintigraphy. Both of these methods are associated with beta-adrenergic receptor mechanisms. This study was conducted to demonstrate the relation between myocardial response to dobutamine stress and sympathetic nerve release of norepinephrine in the failing heart. In 12 patients with heart failure due to idiopathic dilated cardiomyopathy, the myocardial effects of dobutamine stress were evaluated by low-dose dobutamine stress echocardiography: and sympathetic nerve function was evaluated by scintigraphic imaging with iodine-123 [123I] meta-iodobenzylguanidine (MIBG), an analogue of norepinephrine. Echocardiography provided quantitative assessment of wall motion and left ventricular dilation; radiotracer studies with 123I-MIBG provided quantitative assessment of the heart-to-mediastinum (H/M) uptake ratio and washout rate. Results showed that H/M correlated with baseline wall motion (r = 0.682, p = 0.0146), wall motion after dobutamine stress (r = 0.758, p = 0.0043), the change in wall motion (r = 0.667, p = 0.0178), and with left ventricular diastolic diameter (r = 0.837, p = 0.0007). In addition, the 123I-MIBG washout rate correlated with baseline wall motion (r = 0.608, p = 0.0360), wall motion after dobutamine stress (r = 0.703, p = 0.0107), and with the change in wall motion (r = 0.664, p = 0.0185). Wall motion, especially in the myocardial response to dobutamine stress, is related to sympathetic nerve activity in heart failure. [ABSTRACT FROM AUTHOR]