RESUMO
OBJECTIVE: 18F-Fluoro-L-dihydroxyphenylalanine (18F-DOPA) PET offers high sensitivity and specificity in the imaging of non-malignant extra-adrenal paraganglioma (PGL) and pheochromocytoma (PHEO) but lower sensitivity in metastatic disease. These tumours are of neuroendocrine origin and can be detected by 68Ga-DOTA-Tyr3-octreotide (68Ga-DOTA-TOC) PET. Therefore, we compared 68Ga-DOTA-TOC and 18F-DOPA as radiolabels for PET/CT imaging for the diagnosis of metastatic extra-adrenal PGL and PHEO. Combined cross-sectional imaging was the reference standard. METHODS: A total of 6 men and 4 women (age range 22-72 years) with anatomical and/or histologically proven metastatic PGL and PHEO were included in this study. Of these patients, 2 male patients suffered from PHEO, while the remaining 8 patients were diagnosed as metastatic extra-adrenal PGL disease. Comparative evaluation included morphological imaging with CT and functional imaging with 68Ga-DOTA-TOC and 18F-DOPA PET. The imaging results were analyzed on a per-lesion basis. The maximum standardized uptake value (SUVmax) of each functional imaging modality in concordant tumour lesions was measured. RESULTS: Compared with anatomical imaging, the per-lesion detection rate of 68Ga-DOTA-TOC was 100% (McNemar, P<0.01), and that of 18F-DOPA PET was 82.3% (McNemar, P<0.8) in metastatic extra-adrenal PGL and PHEO. Overall, 68Ga-DOTA-TOC PET identified 67 lesions; anatomical imaging identified 62 lesions, and 18F-DOPA PET identified 56 lesions. The SUVmax (mean±SD) of all concordant lesions was 29.3±19.9 for 68Ga-DOTA-TOC PET and 12.3±9.1 for 18F-DOPA PET (Mann-Whitney U test, P<0.0001). CONCLUSION: 68Ga-DOTA-TOC PET offers the highest detection rate in metastatic extra-adrenal PGL and PHEO compared to 18F-DOPA PET and even to diagnostic CT, particularly in bone lesions. Combined functional/anatomical imaging (68Ga-DOTA-TOC PET/CT) enables exact tumour extension to be detected in these rare tumour entities, especially in the case of unclear anatomical correlation.
Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Di-Hidroxifenilalanina/análogos & derivados , Compostos Organometálicos , Paraganglioma Extrassuprarrenal/diagnóstico por imagem , Feocromocitoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: The purpose of this study was to assess the impact of bevacizumab alone and in combination with cytotoxic therapy on tumour vasculature in osteosarcoma (OS) using DCE-MRI. METHODS: Six DCE-MRI and three (18)F-FDG PET examinations were scheduled in 42 subjects with newly diagnosed OS to monitor the response to antiangiogenic therapy alone and in combination with cytotoxic therapy before definitive surgery (week 10). Serial DCE-MRI parameters (K(trans), v(p), and v(e)) were examined for correlation with FDG-PET (SUV(max)) and association with drug exposure, and evaluated with clinical outcome. RESULTS: K(trans) (P=0.041) and v(p) (P=0.001) significantly dropped from baseline at 24 h after the first dose of bevacizumab alone, but returned to baseline by 72 h. Greater exposure to bevacizumab was correlated with larger decreases in v(p) at day 5 (P=0.04) and week 10 (P=0.02). A lower K(trans) at week 10 was associated with greater percent necrosis (P=0.024) and longer event-free survival (P=0.034). CONCLUSIONS: This is the first study to demonstrate significant changes of the plasma volume fraction and vascular leakage in OS with bevacizumab alone. The combination of demonstrated associations between drug exposure and imaging metrics, and imaging metrics and patient survival during neoadjuvant therapy, provides a compelling rationale for larger studies using DCE-MRI to assess vascular effects of therapy in OS.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Bevacizumab/uso terapêutico , Osteossarcoma/tratamento farmacológico , Osteossarcoma/terapia , Quimioterapia Adjuvante/métodos , Criança , Meios de Contraste/administração & dosagem , Intervalo Livre de Doença , Feminino , Fluordesoxiglucose F18 , Gadolínio DTPA , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Terapia Neoadjuvante/métodos , Tomografia por Emissão de Pósitrons/métodosRESUMO
Neuroblastoma is the third most common malignant solid tumor of childhood. It originates from primitive neural crest cells of the sympathetic nervous system. Many imaging procedures help guide therapy and predict outcomes. Anatomic imaging methods, such as CT and MRI, are most useful for evaluation of the primary tumor mass and nearby involved lymph nodes. Functional imaging tracers, such as [123I]MIBG, [18F]FDG, and [99mTc]MDP, are used to assess the extent of disease and to search for distant metastases. [123I]MIBG is the principal functional imaging tracer for the detection and monitoring of neuroblastoma. [18F]FDG PET/CT is an alternative that is valuable in tumors with poor or no MIBG-uptake. [99mTc]MDP bone scans may be useful to assess cortical bone metastases. This article will review the use of [123I]MIBG and other functional imaging agents for the management of patients with neuroblastoma.
Assuntos
Neoplasias do Sistema Nervoso Central/diagnóstico , Neoplasias do Sistema Nervoso Central/metabolismo , Diagnóstico por Imagem/métodos , Neuroblastoma/diagnóstico , Neuroblastoma/metabolismo , 3-Iodobenzilguanidina , Criança , Pré-Escolar , Feminino , Fluordesoxiglucose F18 , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética/métodos , Masculino , Oncologia/métodos , Oncologia/tendências , Prognóstico , Cintilografia/métodos , Medronato de Tecnécio Tc 99m , Tomografia Computadorizada por Raios X/métodos , Imagem Corporal TotalAssuntos
Neoplasias Encefálicas/diagnóstico , Ganglioglioma/diagnóstico , Neoplasias Encefálicas/diagnóstico por imagem , Fluordesoxiglucose F18 , Ganglioglioma/diagnóstico por imagem , Humanos , Lactente , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Masculino , Tomografia por Emissão de Pósitrons , Compostos RadiofarmacêuticosRESUMO
Metastatic lesions occur in up to 36% of patients with pheochromocytoma. Currently there is no way to reliably detect or predict which patients are at risk for metastatic pheochromocytoma. Thus, the discovery of biomarkers that could distinguish patients with benign disease from those with metastatic disease would be of great clinical value. Using surface-enhanced laser desorption ionization protein chips combined with high-resolution mass spectrometry, we tested the hypothesis that pheochromocytoma pathologic states can be reflected as biomarker information within the low molecular weight (LMW) region of the serum proteome. LMW protein profiles were generated from the serum of 67 pheochromocytoma patients from four institutions and analyzed by two different bioinformatics approaches employing pattern recognition algorithms to determine if the LMW component of the circulatory proteome contains potentially useful discriminatory information. Both approaches were able to identify combinations of LMW molecules which could distinguish all metastatic from all benign pheochromocytomas in a separate blinded validation set. In conclusion, for this study set low molecular mass biomarker information correlated with pheochromocytoma pathologic state using blinded validation. If confirmed in larger validation studies, efforts to identify the underlying diagnostic molecules by sequencing would be warranted. In the future, measurement of these biomarkers could be potentially used to improve the ability to identify patients with metastatic disease.
Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico , Biomarcadores Tumorais/sangue , Proteínas de Neoplasias/sangue , Feocromocitoma/diagnóstico , Proteoma/análise , Adolescente , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Idoso , Criança , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peso Molecular , Metástase Neoplásica , Feocromocitoma/patologia , ProteômicaRESUMO
Most, but not all, pheochromocytomas can be localized by computed tomography or magnetic resonance imaging. Here we introduce two novel approaches for localization of pheochromocytoma in a patient in whom conventional imaging modalities failed to show the tumor. First, we establish that measurements of plasma free metanephrines coupled with vena caval sampling are useful for localizing occult pheochromocytoma, particularly when elevations in plasma catecholamines are slight or intermittent. Second, we show that positron emission tomographic scanning using the imaging agent 6-[18F]fluorodopamine as a substrate for the norepinephrine transporter offers a highly effective method for tumor localization. These novel approaches may be of value in difficult cases, where biochemical and clinical evidence of pheochromocytoma is compelling, yet conventional imaging modalities fail to locate the tumor.
Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico , Dopamina/análogos & derivados , Recidiva Local de Neoplasia/diagnóstico , Feocromocitoma/diagnóstico , Simportadores , 3-Iodobenzilguanidina , Neoplasias das Glândulas Suprarrenais/sangue , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia , Proteínas de Transporte/análise , Dopamina/farmacocinética , Epinefrina/sangue , Epinefrina/urina , Radioisótopos de Flúor/farmacocinética , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/diagnóstico por imagem , Norepinefrina/sangue , Norepinefrina/urina , Proteínas da Membrana Plasmática de Transporte de Norepinefrina , Normetanefrina/sangue , Normetanefrina/urina , Feocromocitoma/sangue , Feocromocitoma/diagnóstico por imagem , Feocromocitoma/cirurgia , Compostos Radiofarmacêuticos , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X , Veia Cava InferiorRESUMO
Both pheochromocytomas and neuroblastomas can now be identified and located with a high level of accuracy. Scintigraphy with MIBG has become an indispensable diagnostic method for defining the extent and location of many if not most pheochromocytomas. To define the stage, to document the course and to evaluate the response to therapies in patients with neuroblastoma, imaging with MIBG is now essential.
Assuntos
Neuroblastoma/diagnóstico por imagem , Feocromocitoma/diagnóstico por imagem , 3-Iodobenzilguanidina , Humanos , Imageamento por Ressonância Magnética , Neuroblastoma/diagnóstico , Feocromocitoma/diagnóstico , Cintilografia , Compostos Radiofarmacêuticos/farmacologia , Tomografia Computadorizada por Raios XAssuntos
Osteíte Deformante/diagnóstico por imagem , Polegar/diagnóstico por imagem , Idoso , Osso e Ossos/diagnóstico por imagem , Humanos , Masculino , Osteíte Deformante/complicações , Neoplasias da Próstata/complicações , Cintilografia , Compostos Radiofarmacêuticos , Medronato de Tecnécio Tc 99mRESUMO
Malignant pheochromocytomas have exhibited partial responses to treatments with 131-I metaiodobenzylguanidine (MIBG) and with chemotherapy. The authors combined these two therapeutic methods to determine if beneficial effects from each would be additive. Patients with documented malignant pheochromocytomas were recruited with the intent of administering 131-I MIBG in three substantial amounts of radioactivity at 3-month intervals followed by a year of chemotherapy in which cyclophosphamide, dacarbazine, and vincristine were to be given in 21-day cycles. Six patients entered the protocol. After the 131-I MIBG treatments, three patients manifested declines in the presence of tumor (smaller tumor volume or abnormalities on bone and 131-I MIBG scans) and the function of tumor (decreased rate of normetanephrine excretion as the major index). Two patients completed at least 9 months of chemotherapy and showed further reductions in the presence and function of tumors and were classified as having partial responses. Progressive disease afflicted three of the other four subjects. Even though toxicity was minimal from 131-I MIBG, it was sufficient to force reduction in the dosages or duration of chemotherapy. A combination of 131-I MIBG treatments and chemotherapy produced additive effects in reducing malignant pheochromocytomas. Toxicity moderately curtailed the proposed chemotherapy protocol.
Assuntos
3-Iodobenzilguanidina/uso terapêutico , Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Neoplasias das Glândulas Suprarrenais/radioterapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feocromocitoma/tratamento farmacológico , Feocromocitoma/radioterapia , Compostos Radiofarmacêuticos/uso terapêutico , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Idoso , Terapia Combinada , Ciclofosfamida/administração & dosagem , Dacarbazina/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Feocromocitoma/diagnóstico por imagem , Feocromocitoma/secundário , Cintilografia , Vincristina/administração & dosagemRESUMO
PURPOSE: To assess the sensitivity of positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) in pheochromocytomas and, secondarily, to compare images obtained with FDG PET to those obtained with metaiodobenzylguanidine (MIBG) scintigraphy. MATERIALS AND METHODS: Twenty-nine patients with one or more known or subsequently proved pheochromocytomas underwent FDG PET (35 scans) and MIBG scintigraphy (35 scans). Tumor uptake of FDG was quantified on positive PET scans. RESULTS: Tumor uptake of FDG was detected in 22 of 29 patients. Most benign (seven of 12 patients) and most malignant (15 of 17 patients) pheochromocytomas and their metastases avidly concentrated FDG. In four patients whose pheochromocytomas failed to accumulate MIBG, uptake of FDG in the tumors was intense. For the majority of the 16 patients whose tumors concentrated both agents, however, ratings for MIBG images compared to FDG PET images for delineation of the tumor in comparison to background and normal organ accumulation were superior for nine patients (56%) and as good or better for 14 (88%). CONCLUSION: Most pheochromocytomas accumulate FDG. Uptake is found in a greater percentage of malignant than benign pheochromocytomas. FDG PET is especially useful in defining the distribution of those pheochromocytomas that fail to concentrate MIBG.
Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Fluordesoxiglucose F18 , Feocromocitoma/diagnóstico por imagem , Tomografia Computadorizada de Emissão , 3-Iodobenzilguanidina , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Metaiodobenzylguanidine (MIBG) was developed 18 yr ago for scintigraphic imaging of the adrenomedullary tumors pheochromocytoma and neuroblastoma. Many studies have shown the usefulness of this agent for the management of patients with neuroblastoma or pheochromocytoma, and the 131I-labeled form was recently approved by the Food and Drug Administration for use in the U.S. This article summarizes our current concepts on the diagnostic use of MIBG in children. The radioisotopes available for labeling of MIBG and related compounds, the dosimetry, metabolism and mechanisms of uptake and retention are discussed. Our protocols for imaging both 131I-MIBG and 123I-MIBG, along with the normal distribution of these compounds, are reviewed. The use of MIBG for the management of neuroblastoma, and comparisons with other radiotracers available for imaging neuroblastomas are also addressed.
Assuntos
3-Iodobenzilguanidina , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Radioisótopos do Iodo , Neuroblastoma/diagnóstico por imagem , Feocromocitoma/diagnóstico por imagem , Compostos Radiofarmacêuticos , 3-Iodobenzilguanidina/farmacocinética , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Radioisótopos do Iodo/farmacocinética , Doses de Radiação , Cintilografia , Compostos Radiofarmacêuticos/farmacocinéticaRESUMO
OBJECTIVE: Coronary physiology in infants with congenital heart disease remains unclear. Our objective was to better understand coronary physiology in infants with congenital heart disease. METHODS: We used positron emission tomography with nitrogen 13-labeled ammonia to measure myocardial perfusion at rest and with adenosine (142 micrograms/kg/min x 6 minutes) in five infants after anatomic repair of a congenital heart lesion (group I), and in five infants after Norwood palliation for hypoplastic left heart syndrome (group II). The groups were matched for age, weight, and time from the operation. RESULTS: Resting coronary flow in the left ventricle in group I was 1.8 +/- 0.2 ml/min/gm; resting flow in the right ventricle in group II was 1.0 +/- 0.3 ml/min/gm (p = 0.003). Coronary flow with adenosine was 2.6 +/- 0.5 ml/min/gm in group I and 1.5 +/- 0.7 ml/min/gm in group II (p = 0.02). Absolute coronary flow reserve was the same in both groups (1.5 +/- 0.2 in group I vs 1.6 +/- 0.3 in group II, p = 0.45). Oxygen delivery was reduced in group II compared with group I at rest (16.1 +/- 4.2 ml/min/100 gm vs 28.9 +/- 4.42 ml/min/100 gm, p = 0.02) and with adenosine (25.5 +/- 8.1 ml/min/100 gm vs 42.3 +/- 5.8 ml/min/100 gm, p = 0.02). CONCLUSIONS: Infants with repaired heart disease have higher resting flow and less coronary flow reserve than previously reported for adults. After Norwood palliation, infants have less perfusion and oxygen delivery to the systemic ventricle than do infants with a repaired lesion. This may in part explain why the outcome for patients with Norwood palliation is less favorable than for others.
Assuntos
Circulação Coronária/fisiologia , Cardiopatias Congênitas/diagnóstico por imagem , Cardiopatias Congênitas/cirurgia , Coração/diagnóstico por imagem , Síndrome do Coração Esquerdo Hipoplásico/diagnóstico por imagem , Síndrome do Coração Esquerdo Hipoplásico/cirurgia , Cuidados Paliativos , Tomografia Computadorizada de Emissão , Adenosina , Amônia , Estudos de Casos e Controles , Feminino , Cardiopatias Congênitas/fisiopatologia , Humanos , Síndrome do Coração Esquerdo Hipoplásico/fisiopatologia , Lactente , Recém-Nascido , Masculino , Radioisótopos de Nitrogênio , Compostos RadiofarmacêuticosRESUMO
UNLABELLED: The high sensitivity of metaiodobenzylguanidine (MIBG) scintigraphy for sympathomedullary tumors such as neuroblastoma and pheochromocytoma is well documented. The specificity of MIBG scintigraphy for these tumors is also high but has been incompletely characterized for other neural crest tumors and non-neural crest tumors of childhood. METHODS: The medical records and MIBG scans of all children who had undergone MIBG scintigraphy for known or suspected neuroblastoma or pheochromocytoma were retrospectively reviewed at five major referral centers. Those patients found to have pathologies other than neuroblastoma or pheochromocytoma form the basis of this study. RESULTS: One hundred children with a total of 110 lesions met the inclusion criteria. All had negative MIBG scans except 1 of 2 children with infantile myofibromatosis, 1 of 2 with neuroendocrine carcinomas, 1 of 2 with pancreaticoblastomas and 1 of 10 with primitive neuroectodermal tumors. CONCLUSION: MIBG scintigraphy is highly specific for neuroblastoma and pheochromocytoma. Only 4% (4/100) of nonsympathomedullary tumors (non-pheochromocytoma and non-neuroblastoma) in childhood showed MIBG uptake, of which only 2% (2/100) were of non-neural crest origin.
Assuntos
Radioisótopos do Iodo , Iodobenzenos , Neuroblastoma/diagnóstico por imagem , Feocromocitoma/diagnóstico por imagem , 3-Iodobenzilguanidina , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Cintilografia , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Gas exchange is improved during partial liquid ventilation (PLV) with perfluorocarbon in animal models of acute lung injury. The mechanisms are not fully defined. We hypothesize that redistribution of pulmonary blood flow (PBF) along with redistribution of, and decrease in, total lung water (TLW) during PLV may improve oxygenation. METHODS: We characterized PBF and TLW in anesthetized adult dogs by using positron emission tomography with H2(15)O. Measurements of gas exchange, PBF, and TLW were made before and after acute lung injury was induced with intravenous oleic acid. The same measurements were made during PLV (with 30 ml/kg perfluorocarbon) and compared with gas ventilated (GV) controls. RESULTS: Oxygenation was significantly improved during PLV. PBF redistributed from the dependent zone of the lung to the nondependent zones, thus potentially improving ventilation/perfusion relationships. However, a similar pattern of PBF redistribution was observed during GV such that there was no significant difference between groups. TLW redistributed in a similar pattern during PLV. By quantitative measurements, PLV ameliorated the continued accumulation of TLW compared with GV animals. CONCLUSIONS: We conclude that PBF and TLW redistribution and attenuation of increases in TLW may contribute to the improvement in gas exchange during PLV in the setting of acute lung injury.
Assuntos
Água Corporal/fisiologia , Lesão Pulmonar , Pulmão/fisiologia , Circulação Pulmonar/fisiologia , Ventilação Pulmonar , Animais , Cães , Fluorocarbonos , Pulmão/diagnóstico por imagem , Radioisótopos de Oxigênio , Fluxo Sanguíneo Regional , Fatores de Tempo , Tomografia Computadorizada de EmissãoRESUMO
PURPOSE: Wilms tumor is the most common renal neoplasm in children. The diagnosis is usually suggested by anatomic imaging and established by biopsy or resection. The principal roles of functional imaging have been the search for skeletal metastases and evaluation of renal function. We hypothesized that, like many tumors, Wilms tumors could concentrate 18F-FDG and that evaluation of the metabolic activity of these neoplasms might prove clinically useful. MATERIALS AND METHODS: Three patients with known or suspected Wilms tumors underwent positron emission tomography (PET) with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) scanning (four scans). A patient with a single Wilms tumor was studied once at the time of diagnosis. The two patients with bilateral Wilms tumors were studied during therapy. RESULTS: Uptake of FDG was present in the Wilms tumor studied at diagnosis, and in one of the tumors in each of the patients with bilateral disease studied during therapy. In all three cases, the results of the PET scans influenced therapeutic decisions. CONCLUSION: PET FDG scanning may be useful for the management of selected patients with Wilms tumors.
Assuntos
Desoxiglucose/análogos & derivados , Radioisótopos de Flúor , Neoplasias Renais/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tumor de Wilms/diagnóstico por imagem , Pré-Escolar , Feminino , Fluordesoxiglucose F18 , Humanos , Tomografia Computadorizada de EmissãoRESUMO
We describe a patient with unexplained hypercalcemia who under went bone scintigraphy, which demonstrated marked tracer uptake within the hilar lymph nodes. The pattern strongly suggested sarcoidosis, which was subsequently confirmed by bronchoscopy-directed biopsy.
Assuntos
Doenças Linfáticas/diagnóstico por imagem , Sarcoidose/diagnóstico por imagem , Medronato de Tecnécio Tc 99m , Adulto , Osso e Ossos/diagnóstico por imagem , Feminino , Humanos , Hipercalcemia/etiologia , Doenças Linfáticas/diagnóstico , Cintilografia , Insuficiência Renal/etiologia , Sarcoidose/diagnósticoRESUMO
OBJECTIVE: The imaging features of intrapericardial paragangliomas (pheochromocytomas) are described. MATERIALS AND METHODS: We conducted a retrospective study of the imaging features of all intrapericardial paragangliomas seen at our institution over the last 13 years. RESULTS: In this study, intrapericardial paragangliomas were typically located adjacent to or involved the left atrium. The diameter of the tumors ranged from 3 to 8 cm. Metaiodobenzylguanidine (MIBG) scintigraphy revealed 11 of 12 tumors (sensitivity = 92%). After MIBG scintigraphic location, dynamic contrast-enhanced CT revealed all 12 tumors. CONCLUSION: Intrapericardial paragangliomas are rare tumors, typically located adjacent to or involving the left atrium. For initial detection, regional location of these extraadrenal tumors, and detection of distant metastases, MIBG scintigraphy is recommended. Dynamic contrast-enhanced CT or MR imaging can then provide detailed anatomic delineation before surgical resection.
Assuntos
Neoplasias Cardíacas/diagnóstico , Feocromocitoma/diagnóstico , 3-Iodobenzilguanidina , Adulto , Meios de Contraste , Feminino , Coração/diagnóstico por imagem , Átrios do Coração , Neoplasias Cardíacas/epidemiologia , Humanos , Radioisótopos do Iodo , Iodobenzenos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Feocromocitoma/epidemiologia , Cintilografia , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
This article summarizes the major PET studies which have been performed in pediatric patients to elucidate and characterize diseases and normal development. Issues special for the application of the technique in children, such as dosimetry, patient preparation, and image acquisition are discussed. Studies of central nervous system (CNS) development and pathology, including epilepsy, intraventricular hemorrhage, neonatal asphyxia, tumors, and effects on the CNS from treatment of other tumors are reviewed. These have contributed information fundamental to our understanding of CNS development and pathology. PET investigations into the pathophysiology of congenital heart disease have begun and hold great promise to aid our understanding of these conditions. The second major area in which PET has been applied is the study of non CNS neoplasms. Neuroblastoma has been investigated with tracers which explore basic biochemical features which characterize this tumor, as well as with tracers which explore biochemical events relatively specific for this malignancy. Other common and uncommon tumors of childhood are discussed. The PET technique has been shown useful for answering questions of clinical relevance for the management of these uncommon neoplasms. PET, using tracers that reflect basic metabolic processes, is likely to continue to aid our understanding of many pediatric diseases and may gain more widespread clinical acceptance as the technology continues to disseminate rapidly.
Assuntos
Doenças do Sistema Nervoso Central/diagnóstico por imagem , Radioisótopos de Flúor , Fluordesoxiglucose F18 , Cardiopatias Congênitas/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão , Criança , Pré-Escolar , Humanos , LactenteRESUMO
UNLABELLED: Possible incremental diagnostic benefits of SPECT and delayed planar imaging with [123I]MIBG in neuroblastoma have not yet been fully established. METHODS: Whole-body delayed planar [123I]MIBG imaging at 48 hr and SPECT imaging of the chest-abdomen or other suspected sites obtained at 24 hr were compared with routine planar imaging at 24 hr in 83 studies of 29 children with neuroblastoma. The sensitivity for each of the [123I]MIBG imaging methods was calculated on a study-by-study and on a lesion-by-lesion basis. RESULTS: Fifty-one planar imaging studies were performed in 20 patients with evidence of disease which was detected in 48 studies by 24-hr imaging (94.1% sensitivity) and in 44 studies by 48-hr imaging (86.3% sensitivity). On a lesion-by-lesion basis, sensitivity was 88.8% for the 24-hr scan, 86.7% for the 48-hr scan and 92.2% for a combination of the two (p = ns). Forty-three SPECT studies were performed in 20 patients with evidence of disease in the field of view of the SPECT camera. Disease was detected in 40 SPECT studies (93% sensitivity), in 38 planar scans at 24 hr (84.4% sensitivity) and in 37 planar scans at 48 hr (86.0% sensitivity). On a lesion-by-lesion basis, sensitivity was 83.6% for the 24-hr planar scan, 86.1% for the 48-hr planar scan, 88.2% for a combination of the two planar scans and 97.9% for SPECT (p < 0.001 compared with planar). The anatomic locations of tumors were clearer on SPECT in 15 studies. CONCLUSION: Delayed 48-hr planar scanning may occasionally depict more lesions than 24-hr imaging, but it may also miss lesions with rapid washout. SPECT imaging significantly increases the number of lesions detected and better defines anatomic location of tumors.
Assuntos
Radioisótopos do Iodo , Iodobenzenos , Neuroblastoma/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , 3-Iodobenzilguanidina , Pré-Escolar , Meios de Contraste , Feminino , Humanos , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade , Fatores de TempoRESUMO
PURPOSE: To assess the uptake in neuroblastoma of 2-[fluorine-18] -fluoro-2-deoxy-D-glucose (FDG) versus metaiodobenzylguanidine (MIBG). MATERIALS AND METHODS: Seventeen patients with known or suspected neuroblastoma underwent FDG positron emission tomography (PET) (20 scans) and MIBG scintigraphy. Tumor uptake of FDG was quantified on positive PET scans. RESULTS: Tumor uptake of FDG was detected in 16 of 17 patients (18 of 20 scans). Neuroblastomas and their metastases avidly concentrated FDG prior to chemotherapy or radiation therapy. Uptake after therapy was variable. Uptake of FDG was intense in one patient with neuroblastoma that failed to accumulate MIBG. In 13 of the 20 scans, however, MIBG was rated superior to FDG for delineation of tumor compared with background and normal organs. CONCLUSION: Most neuroblastomas accumulate FDG. The mechanism of MIBG uptake is more intense prior to therapy. Concentration of FDG is not dependent on type 1 catecholamine uptake. FDG PET helps define the distribution of neuroblastomas that fail to concentrate MIBG.