RESUMO
BACKGROUND: Increased thermogenic activity has shown to be a promising target for treating and preventing obesity and type 2 diabetes (T2DM). Little is known about the muscular influence on nonshivering thermogenesis (NST), and it remains unclear whether physical training and potential metabolic improvements could be associated with changes in this type of thermogenic activity. OBJECTIVE: The present study aimed to assess muscular NST activity in overweight and T2DM before and after a combined training period (strength training followed by aerobic exercise). METHODS: Nonshivering cold-induced 18-fluoroxyglucose positron emission computed tomography (18F-FDG PET/CT) was performed before and after 16 weeks of combined training in 12 individuals with overweight and T2DM. The standard uptake value (SUV) of 18F-FDG was evaluated in skeletal muscles, the heart and the aorta. RESULTS: Muscles in the neck region exhibit higher SUV pre- and posttraining. Furthermore, a decrease in glucose uptake by the muscles of the lower and upper extremities and in the aorta was observed after training when adjusted for brown adipose tissue (BAT). These pre-post effects are accompanied by increased cardiac SUV and occur concurrently with heightened energy expenditure and metabolic improvements. CONCLUSIONS: Muscles in the neck region have greater metabolic activity upon exposure to cold. In addition, combined training appears to induce greater NST, favoring the trunk and neck region compared to limbs based on joint work and adaptations between skeletal muscles and BAT.
Assuntos
Diabetes Mellitus Tipo 2 , Metabolismo Energético , Fluordesoxiglucose F18 , Músculo Esquelético , Sobrepeso , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos , Treinamento Resistido , Termogênese , Humanos , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/terapia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Fluordesoxiglucose F18/administração & dosagem , Feminino , Sobrepeso/fisiopatologia , Sobrepeso/terapia , Sobrepeso/metabolismo , Treinamento Resistido/métodos , Resultado do Tratamento , Compostos Radiofarmacêuticos/administração & dosagem , Fatores de Tempo , Adulto , Terapia por Exercício/métodos , IdosoRESUMO
Background: In people, extrarenal pelvis is a normal anatomical variant, characterized by the protusion of the pelvis out of the renal hilum, which can be associated with other anomalies, or predispose to stasis or infection. While other diagnostic imaging methods provide anatomical and morphological information about the kidney, scintigraphy allows to determine the renal function and has greater sensitivity in the detection of functional alterations. The aim of this work is to report the case of an asymptomatic cat diagnosed with extrarenal pelvis detected by scintigraphy, which presented alterations in laboratory and renal imaging tests, and absence of associated obstructive process. Case: A 7-year-old mixed-breed female cat was evaluated for a routine health assessment at the Veterinary Teaching Hospital of the Federal University of Rio Grande do Sul (HCV-UFRGS). When performing the imaging and laboratory tests, renal alterations compatible with chronic kidney disease were found in the abdominal ultrasonography examination and in serum creatinine levels. Therefore, it was decided to perform scintigraphy evaluation to better assess renal function. Dynamic renal scintigraphy with 99mTcDTPA revealed an evident concentration of the radiotracer in the left kidney with effective elimination only after the diuretic stimulus. The right kidney exhibited less concentration of the radiotracer but showed effective elimination before the diuretic stimulus. Image analysis suggested the presence of an extrarenal pelvis on the left side. The relative renal uptake was 68% for the left kidney and 32% for the right kidney. The glomerular filtration rate was 1.65 mL/min/kg. Static renal scintigraphy with 99mTcDMSA revealed irregularity in the distribution of the radiotracer in both kidneys, showing less activity in the caudal pole of the left kidney. The right kidney was apparently reduced and with less activity, especially in the medial portion. The relative renal uptake was 65% for the left kidney and 35% for right kidney, while the absolute renal uptake of the left kidney was 33% and that of the right kidney was 17%. The alteration described in the left kidney, in correlation with dynamic renal scintigraphy, suggested an aspect of lower activity in the caudal pole due to the presence of activity in the extrarenal pelvis. The left kidney was classified as presenting normal renal function and there was moderate to severe deficit of renal function on the right side. Discussion: Chronic kidney disease may be present before clinical signs and biochemical abnormalities are identified. In this report, the animal was referred for a routine evaluation and showed no clinical signs nor alterations on physical examination. However, as renal morphological alterations were seen on ultrasonography and the cat presented mild azotemia, it was decided to perform two renal scintigraphy exams. Despite the radiotracer elimination from the left kidney was seen only after the diuretic stimulus, dynamic renal scintigraphy did not show any obstructive process. This delay on elimination was probably a result of the anatomical variant called extrarenal pelvis. In the static renal scintigraphy, it was possible to evaluate morphological changes in the kidneys and suggest less activity in the caudal pole of the left kidney, due to the presence of activity in the extrarenal pelvis, apparently causing the mentioned defect. The correct diagnosis of morphological changes is essential and for this purpose the best combination of imaging tests is necessary. Renal scintigraphy was fundamental, in this case, for the diagnosis of extrarenal pelvis in one of the kidneys, an abnormality not reported in the feline species within the literature researched by the authors. In addition, renal scintigraphy helped to guide the clinical management of the patient described in this report.
Assuntos
Animais , Feminino , Gatos , Pelve/anormalidades , Insuficiência Renal Crônica/veterinária , Insuficiência Renal Crônica/diagnóstico por imagem , Cintilografia/veterinária , Compostos Radiofarmacêuticos/administração & dosagemRESUMO
Nanomedicine is a highly demanded discipline. Liposomes have seen an increased attention due to their physicochemical properties that allow them to act as nanocarriers of drugs and also of radioisotopes that can be used to diagnose and treat cancer. In order to obtain a novel permeability cancer imaging agent based on 99mTc-labeled liposomes, we describe microwave-assisted synthesis of stearyl 6-(benzylidenehydrazinyl) nicotinamide lipid, which was included in two formulations: nanometric hydrazinonicotinic acid (HYNIC) liposome and its PEGylated coated analogue, HYNIC-PEG liposome. Radiolabeling with 99mTc via stearyl 6-(benzylidenehydrazinyl) nicotinamide was found to be easy, reproducible, and stable, revealing high radiochemical purity (94 ± 1.7%) for both liposomal formulations. Biodistribution at 4 h and 24 h and scintigraphic images at 4 h were performed in normal and melanoma-bearing C57BL/6 mice. Biodistribution studies at 4 h showed tumor uptake of 99mTc-HYNIC liposome and 99mTc-HYNIC-PEG liposome (1.1 ± 0.6 and 2.5 ± 0.4, respectively) and also at 24 h p.i. (1.8 ± 0.5 and 3.0 ± 1.1, respectively). Scintigraphic images showed appreciable tumor uptake in melanoma tumor-bearing mice with both liposomal formulations. Our results show that 99mTc stearyl 6-(benzylidenehydrazinyl) nicotinamide liposomes can be used as diagnostic noninvasive in vivo tumor-targeting agents capable of evaluating tumor permeability and development who can be used in personalized chemotherapy planning.
Assuntos
Melanoma Experimental/metabolismo , Niacinamida/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Tecnécio/farmacocinética , Animais , Linhagem Celular Tumoral , Lipossomos , Melanoma Experimental/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Niacinamida/administração & dosagem , Niacinamida/química , Permeabilidade/efeitos dos fármacos , Cintilografia/métodos , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/química , Tecnécio/administração & dosagem , Tecnécio/química , Distribuição Tecidual/efeitos dos fármacos , Distribuição Tecidual/fisiologia , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/fisiologiaRESUMO
The aim of this work was to use TOPAS Monte Carlo simulations to model the effect of magnetic fields on dose distributions in brachytherapy lung treatments, under ideal and clinical conditions. Idealistic studies were modeled consisting of either a monoenergetic electron source of 432 keV, or a polyenergetic electron source using the spectrum of secondary electrons produced by 192Ir gamma-ray irradiation. The electron source was positioned in the center of a homogeneous, lung tissue phantom (ρ = 0.26 g/cm3). Conversely, the clinical study was simulated using the VariSource VS2000 192Ir source in a patient with a lung tumor. Three contoured volumes were considered: the tumor, the planning tumor volume (PTV), and the lung. In all studies, dose distributions were calculated in the presence or absence of a constant magnetic field of 3T. Also, TG-43 parameters were calculated for the VariSource and compared with published data from EGS-brachy (EGSnrc) and PENELOPE. The magnetic field affected the dose distributions in the idealistic studies. For the monoenergetic and poly-energetic studies, the radial distance of the 10% iso-dose line was reduced in the presence of the magnetic field by 64.9% and 24.6%, respectively. For the clinical study, the magnetic field caused differences of 10% on average in the patient dose distributions. Nevertheless, differences in dose-volume histograms were below 2%. Finally, for TG-43 parameters, the dose-rate constant from TOPAS differed by 0.09% ± 0.33% and 0.18% ± 0.33% with respect to EGS-brachy and PENELOPE, respectively. The geometry and anisotropy functions differed within 1.2% ± 1.1%, and within 0.0% ± 0.3%, respectively. The Lorentz forces inside a 3T magnetic resonance machine during 192Ir brachytherapy treatment of the lung are not large enough to affect the tumor dose distributions significantly, as expected. Nevertheless, large local differences were found in the lung tissue. Applications of this effect are therefore limited by the fact that meaningful differences appeared only in regions containing air, which is not abundant inside the human.
Assuntos
Braquiterapia/métodos , Neoplasias Pulmonares/radioterapia , Pulmão/efeitos da radiação , Campos Magnéticos , Braquiterapia/estatística & dados numéricos , Simulação por Computador , Relação Dose-Resposta à Radiação , Elétrons , Humanos , Radioisótopos de Irídio/administração & dosagem , Radioisótopos de Irídio/farmacocinética , Radioisótopos de Irídio/uso terapêutico , Imageamento por Ressonância Magnética , Método de Monte Carlo , Imagens de Fantasmas , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/uso terapêutico , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Distribuição TecidualRESUMO
AIM: The main goal in Crohn´s disease (CD) is a sustained suppression of inflammatory activity associated with mucosa healing in endoscopic evaluation. During clinical routine, there are small numbers of good markers to monitor inflammatory activity under treatment. We postulated that Oral 67Gallium Citrate Scintigraphy is able to mark inflammatory disease in mucosa and deep inflammation in CD, when used in oral form. OBJECTIVE: Measure the accuracy of Oral 67Gallium Citrate Scintigraphy in intestinal inflammatory activity of Crohn´s disease. PATIENTS AND METHODS: In a prospective consecutive cross-sectional study from January 2018 to June 2019, the ileocolonic region of 32 patients with CD were studied by dividing into four regions of interest (ROI) from the ileum to the rectum. A total of 128 intestinal segments were analyzed in cluster data. Accuracy values of Oral 67Gallium Scintigraphy and colonoscopy tests were evaluated with the histological reference test. Values of the respective receiver operating characteristic (ROC) curves were obtained and compared. The reliability between the tests was evaluated by Kappa statistical with the segment-level analyses using variance adjustments. All statistical analyses were performed with a test significance level of 0.05. RESULTS: The study population included 32 patients with CD (10 men, 22 women; average age 39 years). Disease time was five years on average. Anti-TNFs treatment was found in 71%. The most found phenotype of the Montreal classification was L3. Differences in ROC curves for colonoscopy (0.94) and Oral 67Ga Scintigraphy (0.96) did not show significant value (p = 0.32). The sensitivity of scintigraphy to detect intestinal inflammatory activity in CD was 64%, specificity of 96% and accuracy of 84%. A high agreement was found between oral scintigraphy and histological measurements with kappa = 0.64. CONCLUSIONS: Oral 67Ga Scintigraphy had similar accuracy and agreement compared to colonoscopy in the identification of inflammatory activity in Crohn´s Disease. This new approach may be useful and less invasive for long term follow-ups.
Assuntos
Citratos/administração & dosagem , Doença de Crohn/complicações , Radioisótopos de Gálio/administração & dosagem , Gálio/administração & dosagem , Inflamação/diagnóstico por imagem , Cintilografia/métodos , Administração Oral , Adulto , Antineoplásicos/farmacologia , Citratos/química , Estudos Transversais , Feminino , Gálio/química , Radioisótopos de Gálio/química , Humanos , Íleo/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/química , Reto/metabolismo , Reprodutibilidade dos Testes , Medição de Risco , Resultado do Tratamento , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The aim of this work was to develop and evaluate a 99m Tc-labeled neuropeptide Y derivative with affinity toward Y1-receptor. The selected amino acid sequence included nine amino acids derived from the C-terminal portion of the NPY complemented with the addition of one cysteine-mercaptoacetic acid moiety to bind the radiometal. Labeling was achieved through the preparation of a 3 + 1 nitrido complex. Physicochemical evaluation, cell uptake, internalization and externalization studies, and competitive assays were performed. Biodistribution experiments were carried out in normal and tumor-bearing mice. A single product with radiochemical purity >90% and high stability was obtained. In vitro analysis showed specific cellular uptake, IC50 of 73.2 nM, and a high internalization rate (80%). Biodistribution studies showed low blood and renal uptake and combined hepatobiliary and urinary elimination. Preliminary studies in mice bearing induced breast tumors rendered promising uptake values.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neuropeptídeo Y/administração & dosagem , Compostos Radiofarmacêuticos/administração & dosagem , Tecnécio/administração & dosagem , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Compostos Radiofarmacêuticos/farmacocinética , Distribuição TecidualRESUMO
Positron-emission tomography (PET) is a medical diagnostic technique by means of which functional images are obtained by recording the spatio-temporal biodistribution of specific radiopharmaceuticals targeted at specific molecular objectives, which provides biochemical information at the molecular level. Early in the first decade of this 21st century, the Faculty of Medicine of the National Autonomous University of Mexico acquired the technology to implement this diagnostic technique in Mexico, thus becoming a pioneer in PET applications in the country and in Latin America. Almost two decades after its implementation in Mexico, PET has become an essential tool in medical clinics. This article describes the background, current state and perspectives of PET molecular imaging in Mexico, and the impact it has had on the management of patients with oncological, neurological and heart diseases.
La tomografía por emisión de positrones (PET) es una técnica de diagnóstico médico mediante la cual se obtienen imágenes funcionales a partir de registrar la biodistribución espacio-temporal de radiofármacos específicos dirigidos a blancos moleculares específicos, proveyendo información bioquímica a nivel molecular. A principios de la primera década de este siglo XXI, la Facultad de Medicina de la Universidad Nacional Autónoma de México implementó esta técnica de diagnóstico en México, convirtiéndose en pionera en aplicaciones PET en el país y Latinoamérica. Casi dos décadas después, la PET se ha convertido en una herramienta esencial en la clínica médica. En este artículo se describen los antecedentes, el estado actual, las perspectivas de la imagen molecular PET en México y el impacto que ha tenido en el manejo de pacientes con enfermedades oncológicas, neurológicas y cardiológicas.
Assuntos
Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/administração & dosagem , Cardiopatias/diagnóstico por imagem , Humanos , México , Neoplasias/diagnóstico por imagem , Doenças do Sistema Nervoso/diagnóstico por imagemRESUMO
Resumen La tomografía por emisión de positrones (PET) es una técnica de diagnóstico médico mediante la cual se obtienen imágenes funcionales a partir de registrar la biodistribución espacio-temporal de radiofármacos específicos dirigidos a blancos moleculares específicos, proveyendo información bioquímica a nivel molecular. A principios de la primera década de este siglo XXI, la Facultad de Medicina de la Universidad Nacional Autónoma de México implementó esta técnica de diagnóstico en México, convirtiéndose en pionera en aplicaciones PET en el país y Latinoamérica. Casi dos décadas después, la PET se ha convertido en una herramienta esencial en la clínica médica. En este artículo se describen los antecedentes, el estado actual, las perspectivas de la imagen molecular PET en México y el impacto que ha tenido en el manejo de pacientes con enfermedades oncológicas, neurológicas y cardiológicas.
Abstract Positron-emission tomography (PET) is a medical diagnostic technique by means of which functional images are obtained by recording the spatio-temporal biodistribution of specific radiopharmaceuticals targeted at specific molecular objectives, which provides biochemical information at the molecular level. Early in the first decade of this 21st century, the Faculty of Medicine of the National Autonomous University of Mexico acquired the technology to implement this diagnostic technique in Mexico, thus becoming a pioneer in PET applications in the country and in Latin America. Almost two decades after its implementation in Mexico, PET has become an essential tool in medical clinics. This article describes the background, current state and perspectives of PET molecular imaging in Mexico, and the impact it has had on the management of patients with oncological, neurological and heart diseases.
Assuntos
Humanos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/administração & dosagem , Cardiopatias/diagnóstico por imagem , México , Neoplasias/diagnóstico por imagem , Doenças do Sistema Nervoso/diagnóstico por imagemRESUMO
Cardiac sympathetic overdrive provides inotropic support to the failing heart. However, as myocardial insult evolves, this compensatory response impairs contractile function and constitutes an independent mortality predictor and a primary target in the treatment of heart failure (HF). In this prospective, randomized, double-blind, controlled crossover trial, we proposed cervicothoracic transcutaneous electrical nerve stimulation (CTENS) as a nonpharmacological therapy on cardiac sympathetic activity in patients with HF. Seventeen patients with HF were randomly assigned to an in-home CTENS (30 min twice daily, 80-Hz frequency, and 150-µs pulse duration) or a control intervention (Sham) for 14 consecutive days. Following a 60-day washout phase, patients were crossed over to the opposite intervention. The heart-to-mediastinum ratio (HMR) and washout rate (WR) (indexes of sympathetic innervation density and activity from planar 123iodo-metaiodobenzylguanidine myocardial scintigraphy images, respectively), as well as blood pressure (BP) and heart rate (HR), were quantified before and after each intervention. HMR, BP, and HR did not change throughout the study. Nonetheless, CTENS reduced WR (CTENS -4 ± 10 vs. Sham +5 ± 15%, P = 0.03) when compared with Sham. When allocated in two independent groups, preserved (PCSI, HMR > 1.6, n = 10) and impaired cardiac sympathetic innervation (ICSI, HRM ≤1.6, n = 7), PCSI patients showed an important attenuation of WR (-11 ± 9 vs. Sham +8 ± 19%, P = 0.007) after CTENS. Nonetheless, neither Sham nor CTENS evoked changes in WR of the ICSI patients (P > 0.05). These findings indicate that CTENS attenuates the cardiac sympathetic overdrive in patients with HF and a preserved innervation constitutes an essential factor for this beneficial neuromodulatory impact. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Identifier: NCT03354689. NEW & NOTEWORTHY We found that short-term cervicothoracic transcutaneous electrical nerve stimulation (CTENS) attenuates cardiac sympathetic overdrive in patients with heart failure and a preserved autonomic innervation may constitute an essential factor to maximize this beneficial neuromodulatory effect. CTENS then emerges as an alternative noninvasive and nonpharmacological strategy to attenuate exaggerated cardiac sympathetic drive in patients with heart failure.
Assuntos
3-Iodobenzilguanidina/administração & dosagem , Insuficiência Cardíaca/terapia , Coração/inervação , Radioisótopos do Iodo/administração & dosagem , Contração Miocárdica , Compostos Radiofarmacêuticos/administração & dosagem , Sistema Nervoso Simpático/fisiopatologia , Estimulação Elétrica Nervosa Transcutânea , Idoso , Pressão Sanguínea , Brasil , Estudos Cross-Over , Método Duplo-Cego , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema Nervoso Simpático/diagnóstico por imagem , Fatores de Tempo , Estimulação Elétrica Nervosa Transcutânea/efeitos adversos , Resultado do TratamentoRESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) can be the last step of non-alcoholic fatty liver disease (NAFLD) evolution. Experimental models are crucial to elucidate the pathogenesis of HCC secondary to NAFLD. The 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating HCC development and progression. OBJECTIVE: To standardize the imaging method of PET/CT with 18F-FDG as an evaluation tool of the experimental model of HCC secondary to NAFLD. METHODS: Ten male Sprague-Dawley rats were fed with choline-deficient high-fat diet and diethylnitrosamine (DEN) in the drinking water for 16 weeks and then received 1 mL of saline solution (0.9%) daily by gavage for three weeks. At the 16th and 19th weeks, abdominal ultrasonography (USG) was performed. 18F-FDG PET/CT images were obtained before the beginning of experiment (week 0) and at the end (week 19). Histological and immunohistochemically analysis were also performed. RESULTS: The USG results showed a homogeneous group at the 16th week with an average of 4.6±2.74 nodules per animal. At the 19th week, PET/CT findings demonstrated an average of 8.5±3.7 nodules per animal. The mean values of SUVmed and SUVmax were 2.186±0.1698 and 3.8±1.74, respectively. The average number of nodules per animal in the histological analysis was 5.5±1.5. From all nodules, 4.6% were classified as well-differentiated HCC and 81.8% were classified as poorly-differentiated HCC. CONCLUSION: 18F-FDG PET/CT was able to evaluate the development of HCC in an experimental model of NAFLD non-invasively. From the standardization of PET/CT in this model, it is possible to use this tool in future studies to monitor, in vivo and non-invasively, the progression of HCC.
Assuntos
Carcinoma/diagnóstico por imagem , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Animais , Carcinoma/patologia , Carcinoma/secundário , Modelos Animais de Doenças , Fluordesoxiglucose F18/administração & dosagem , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas Experimentais/secundário , Masculino , Gradação de Tumores , Estadiamento de Neoplasias , Hepatopatia Gordurosa não Alcoólica/complicações , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/normas , Prognóstico , Compostos Radiofarmacêuticos/administração & dosagem , Ratos Sprague-Dawley , UltrassonografiaRESUMO
ABSTRACT BACKGROUND: Hepatocellular carcinoma (HCC) can be the last step of non-alcoholic fatty liver disease (NAFLD) evolution. Experimental models are crucial to elucidate the pathogenesis of HCC secondary to NAFLD. The 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating HCC development and progression. OBJECTIVE: To standardize the imaging method of PET/CT with 18F-FDG as an evaluation tool of the experimental model of HCC secondary to NAFLD. METHODS: Ten male Sprague-Dawley rats were fed with choline-deficient high-fat diet and diethylnitrosamine (DEN) in the drinking water for 16 weeks and then received 1 mL of saline solution (0.9%) daily by gavage for three weeks. At the 16th and 19th weeks, abdominal ultrasonography (USG) was performed. 18F-FDG PET/CT images were obtained before the beginning of experiment (week 0) and at the end (week 19). Histological and immunohistochemically analysis were also performed. RESULTS: The USG results showed a homogeneous group at the 16th week with an average of 4.6±2.74 nodules per animal. At the 19th week, PET/CT findings demonstrated an average of 8.5±3.7 nodules per animal. The mean values of SUVmed and SUVmax were 2.186±0.1698 and 3.8±1.74, respectively. The average number of nodules per animal in the histological analysis was 5.5±1.5. From all nodules, 4.6% were classified as well-differentiated HCC and 81.8% were classified as poorly-differentiated HCC. CONCLUSION: 18F-FDG PET/CT was able to evaluate the development of HCC in an experimental model of NAFLD non-invasively. From the standardization of PET/CT in this model, it is possible to use this tool in future studies to monitor, in vivo and non-invasively, the progression of HCC.
RESUMO BACKGROUND: O carcinoma hepatocelular (CHC) pode ser a última fase da doença hepática gordurosa não alcoólica (DHGNA). Modelos experimentais são cruciais para elucidação da patogênese do CHC secundário a DHGNA. A tomografia por emissão de pósitrons/tomografia computadorizada (PET/TC) com 2-desoxi-2-(18F)fluoro-D-glicose (18F-FDG) desempenha um importante papel na avaliação do desenvolvimento e progressão do CHC. OBJETIVO: Padronizar a metodologia de imagem por PET/TC com 18F-FDG como uma ferramenta de avaliação do modelo experimental de CHC secundário a DHGNA. MÉTODOS: Dez ratos Sprague-Dawley machos foram alimentados com dieta hiperlipídica deficiente em colina associada a dietilnitrosamina (DEN) na água de beber por 16 semanas e depois receberam 1 mL de solução salina (0,9%) por gavagem diariamente por três semanas. Nas 16ª e 19ª semanas, foi realizada a ultrassonografia abdominal. As imagens do PET/TC com 18F-FDG foram obtidas antes do início do experimento (semana 0) e no final (semana 19). Análises histológica e imunohistoquímica também foram realizadas. RESULTADOS: Os resultados da ultrassonografia demonstraram um grupo homogêneo na 16ª semana com uma média de 4,6±2,74 nódulos por animal. Na 19ª semana, os achados do PET/CT demonstraram uma média de 8,5±3,7 nódulos por animal. Os valores médios de SUVmed e SUVmáx foram 2,186±0,1698 e 3,8±1,74, respectivamente. A média do número de nódulos na análise histológica foi de 5,5±1,5. De todos os nódulos, 4,6% foram classificados como bem diferenciados e 81,8% foram classificados como CHC pouco diferenciado. CONCLUSÃO: O PET/TC com 18F-FDG foi capaz de avaliar o desenvolvimento do CHC secundário a DHGNA de forma não invasiva. A partir da padronização do PET/CT neste modelo, faz-se possível a utilização desta ferramenta em futuros estudos para monitorar, in vivo e de forma não invasiva, a progressão do CHC.
Assuntos
Animais , Masculino , Carcinoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Prognóstico , Carcinoma/patologia , Carcinoma/secundário , Ultrassonografia , Ratos Sprague-Dawley , Compostos Radiofarmacêuticos/administração & dosagem , Fluordesoxiglucose F18/administração & dosagem , Modelos Animais de Doenças , Gradação de Tumores , Hepatopatia Gordurosa não Alcoólica/complicações , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/normas , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas Experimentais/secundário , Estadiamento de NeoplasiasRESUMO
It has been suggested that technetium-99m (99mTc)-anti-tumour necrosis factor alpha (TNF-α) scintigraphy (SCI) may be a useful diagnostic tool in Graves' ophthalmopathy (GO). This study evaluated whether orbit total radioactivity uptake on SCI could be used to predict corticosteroid therapy (CorT) responses in active-GO patients. A longitudinal study of patients with active GO defined by Clinical Active Score (CAS) >3/7 was done. Clinical, laboratory and SCI evaluations were performed at baseline and 3 months after concluding intravenous CorT. SCI (planar and tomographic) was assessed after intravenous injection of 10 mCi of 99mTc-anti-TNF-α. Orbits and cerebral hemispheres were defined as regions of interest (ROIs) to enable orbit/hemisphere ROI-ratios of total radioactive uptake. ROI-ratios were considered positive at >2·5. Average total radiation uptake (TRU) was also determined for each orbit (AVGROI ). Clinical, laboratory and SCI data were compared between responders (CAS became inactive) and non-responders to CorT (18 patients). At baseline, AVGROI were higher in active OG orbits (67·3 cps) than in inactive ones (33·6 cps; P<0·05). AVGROI (absolute values) reduced (-29·9 cps) in CorT responders and tended (P = 0·067) to differ from variations occurred in non-responders (+6·9 cps in patients with maintained CAS positivity post-treatment). Higher baseline ROI-ratios (4·9 versus 3·3; P = 0·056) and its pronounced reductions following CorT (-37% versus +56% in non-responders; P = 0·036) tended to be associated with good CorT responses in the subgroup of GO history ≥1 year. SCI showed a good association with active eye disease and may be an additional tool to identify CorT responders.
Assuntos
Adalimumab/administração & dosagem , Corticosteroides/uso terapêutico , Oftalmopatia de Graves/diagnóstico por imagem , Oftalmopatia de Graves/tratamento farmacológico , Compostos Radiofarmacêuticos/administração & dosagem , Tecnécio/administração & dosagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Feminino , Oftalmopatia de Graves/imunologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Indução de Remissão , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento , Fator de Necrose Tumoral alfa/imunologiaRESUMO
BACKGROUND: Hepatopulmonary syndrome (HPS) is defined as a triad characterized by arterial deoxygenation, intrapulmonary vascular dilatations (IPVDs), and liver disorder. The aims of this study were to assess the prevalence of HPS in children with cirrhosis, the clinical characteristics of patients with HPS, and the tests used for the diagnosis of IPVD. PATIENTS AND METHODS: This was a prospective, cross-sectional study of 40 children with cirrhosis (median age: 44 months). Investigations of HPS included arterial blood gas analysis, contrast-enhanced transthoracic echocardiography (CE-TTE), and perfusion lung scanning using technetium-99m-labeled macroaggregated albumin (Tc-MMA). Patients' clinical characteristics (age, etiology of cirrhosis, and severity of hepatopathy) were assessed. HPS was defined as liver disease; alveolar-arterial oxygen gradient of at least 15 mmHg and/or partial pressure of arterial oxygen less than 80 mmHg; and detection of IPVD by CE-TTE or Tc-MMA scanning. Statistical significance was indicated by a P value less than 0.05. RESULTS: The prevalence of HPS was 42.5% (17/40). Eight patients had moderate HPS (47%) and two patients had severe HPS (12%). In bivariate analysis, biliary atresia (P=0.033) and median age (10 months; P=0.005) were associated with HPS. In multivariate analysis, only age remained statistically significant (prevalence ratio=0.99; 95% confidence interval=0.98-0.99; P=0.010). Sixteen patients with HPS had IPVD detected by CE-TTE (94.1%) and six patients had IPVD detected by Tc-MMA scanning (35.3%), with no significant agreement between these methods (κ=-0.12; P=0.163). CONCLUSION: HPS is a common complication of cirrhosis in children. A combination of clinical and imaging criteria should be used to diagnose HPS.
Assuntos
Síndrome Hepatopulmonar/epidemiologia , Cirrose Hepática/epidemiologia , Adolescente , Fatores Etários , Gasometria , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Ecocardiografia , Feminino , Síndrome Hepatopulmonar/diagnóstico por imagem , Síndrome Hepatopulmonar/fisiopatologia , Humanos , Lactente , Cirrose Hepática/diagnóstico , Cirrose Hepática/fisiopatologia , Masculino , Imagem de Perfusão/métodos , Valor Preditivo dos Testes , Prevalência , Prognóstico , Estudos Prospectivos , Compostos Radiofarmacêuticos/administração & dosagem , Fatores de Risco , Índice de Gravidade de Doença , Agregado de Albumina Marcado com Tecnécio Tc 99m/administração & dosagemRESUMO
SPECT/CT images in patients have demonstrated the ability of [99mTc]Tc-EDDA/HYNIC-Lys(Nal)-Urea-Glu ([99mTc]Tc-iPSMA) to detect tumors and metastases of prostate cancer. Considering that theranostics combines the potential of therapeutic and diagnostic radionuclides in the same molecular probe, the aim of this research was to estimate the biokinetics and dosimetry of 177Lu-DOTA-HYNIC-Lys(Nal)-Urea-Glu (177Lu-iPSMA) in healthy subjects and analyze the response in patients receiving 177Lu-iPSMA therapeutic doses. 177Lu-iPSMA was obtained from lyophilized formulations with radiochemical purities >98%. Whole-body images from five healthy subjects were acquired at 20 min, 6, 24, 48, and 120 h after 177Lu-iPSMA administration (185 MBq). The image sequence was used to extrapolate the 177Lu-iPSMA time-activity curves of each organ to adjust the biokinetic model and calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation doses. Ten patients (median age: 68 y; range 58-86 y) received from 1 to 4 cycles of 177Lu-iPSMA (3.7 or 7.4 GBq) every 8-10 weeks. Response was evaluated using the 68Ga-PSMA-ligand-PET/CT or 99mTc-iPSMA-SPECT/CT diagnostic images and serum PSA levels before and after 177Lu-iPSMA treatment. The blood activity showed a half-life value of 1.1 h for the fast component (T 1/2 α = ln2/0.614), 9.2 h for the first slow component (T 1/2 ß = ln2/0.075), and 79.6 h for the second slow component (T 1/2 γ = ln2/0.008). The average absorbed doses were 0.23, 0.28, 0.88, and 1.17 Gy/GBq for the spleen, liver, kidney, and salivary glands. A total of 18 cycles were performed in 10 patients. A PSA decrease and some reduction of the radiotracer uptake (SUV) in tumor lesions occurred in 60% and 70% of the patients, respectively. 177Lu-iPSMA obtained from kit formulations showed high tumor uptake with good response rates in patients. The results obtained in this study warrant further clinical studies to establish the optimal number of treatment cycles and for evaluating the effect of this therapeutic agent on survival of patients.
Assuntos
Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Compostos Radiofarmacêuticos/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Idoso de 80 Anos ou mais , Antígenos de Superfície/imunologia , Glutamato Carboxipeptidase II/imunologia , Humanos , Cinética , Lutécio , Masculino , Pessoa de Meia-Idade , Radioisótopos , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/síntese química , Nanomedicina Teranóstica , Fatores de Tempo , Distribuição TecidualRESUMO
OBJECTIVES: Detection rate of thyroid nodules is increasing with the use of new imaging modalities, especially in screening for malignancies. Positron emission tomography/computed tomography (PET/ CT)-positive thyroid nodules should be differentiated for malignancy to avoid unnecessary operations and further follow-up. Most trials evaluate the role of SUVmax, but there is no definitive information about the utility of Hounsfield unit (HU) values for prediction of malignancy. This study aimed to evaluate the HU values beside SUVmax for detecting malignancy risk of PET/CT-positive thyroid nodules. SUBJECTS AND METHODS: Results of 98 cancer patients who had fine needle aspiration biopsy (FNAB) for thyroid nodules detected on PET/CT between January 2011 and December 2015 were assessed. The FNABs and surgical pathological results were recorded. RESULTS: FNABs revealed benign results in 32 patients (32.7%), malignant in 18 (18.4%), non-diagnostic in 20 (20.4%), and indeterminate in 28 (28.5%). Twenty-four patients underwent thyroidectomy. The mean HU values were not significantly different in benign and malignant nodules (p = 0.73). However, the mean SUVmax was significantly higher (p < 0.001) in malignant ones. Area under curve (AUC) was 0.824 for SUVmax; the cut-off value was over 5.55 (p < 0.001), with 80% sensitivity, 84.5% specificity. CONCLUSIONS: Our current study demonstrated that HU value does not add any additional valuable information for discriminating between malignant and benign thyroid nodules. We also defined a SUV cut-off value of 5.55 for malignant potential of thyroid nodules detected on PET/CT Arch Endocrinol Metab. 2018;62(4):460-5.
Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia , Adulto , Idoso , Biópsia por Agulha Fina , Diagnóstico Diferencial , Feminino , Fluordesoxiglucose F18/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos/administração & dosagem , Estudos Retrospectivos , Sensibilidade e Especificidade , Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/diagnóstico por imagem , TireoidectomiaRESUMO
Los pacientes afectados por el cáncer diferenciado de tiroides habitualmente presentan un curso clínico favorable, ya que la piedra angular del tratamiento es la cirugía; a pesar de esto, algunos pueden desarrollar un ominoso desenlace, debido a las características clinico-patológicas de esta enfermedad. El tratamiento óptimo aún es controvertido, en especial respecto a la extensión de la cirugía, indicaciones de radioyodo y la supresión de la hormona estimulante de la tiroides. La correcta evaluación de los riesgos, antes y después de la cirugía, facilita un selectivo enfoque del tratamiento; destacando la relevancia de revisar el impacto de la medicina nuclear en la correcta evaluación, tratamiento y seguimiento de los pacientes que padecen esta neoplasia.Patients affected by differentiated thyroid cancer usually have a favorable clinical course, since the cornerstone of treatment is surgery; despite this, some patients may develop an ominous outcome, due to the clinical-pathological features of this disease. Optimal treatment remains controversial, especially regarding the extent of surgery, indications for radioiodine and thyroid-stimulating hormone. The correct evaluation of risks before and after surgery facilitates a selective treatment approach; highlighting the importance of reviewing the impact of nuclear medicine on the correct evaluation, treatment and follow-up of patients suffering from this neoplasm.
Assuntos
Radioisótopos do Iodo/administração & dosagem , Compostos Radiofarmacêuticos/administração & dosagem , Neoplasias da Glândula Tireoide/terapia , Humanos , Medicina Nuclear/métodos , Neoplasias da Glândula Tireoide/diagnóstico por imagemRESUMO
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.
Assuntos
3-Iodobenzilguanidina/administração & dosagem , Cardiomiopatia Chagásica/complicações , Insuficiência Cardíaca/diagnóstico por imagem , Transplante de Coração , Disautonomias Primárias/diagnóstico por imagem , Compostos Radiofarmacêuticos/administração & dosagem , Adulto , Cardiomiopatia Chagásica/fisiopatologia , Estudos Transversais , Feminino , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Disautonomias Primárias/etiologia , Disautonomias Primárias/fisiopatologia , CintilografiaRESUMO
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.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Cardiomiopatia Chagásica/complicações , Transplante de Coração , Compostos Radiofarmacêuticos/administração & dosagem , 3-Iodobenzilguanidina/administração & dosagem , Disautonomias Primárias/diagnóstico por imagem , Insuficiência Cardíaca/diagnóstico por imagem , Cintilografia , Cardiomiopatia Chagásica/fisiopatologia , Estudos Transversais , Disautonomias Primárias/etiologia , Disautonomias Primárias/fisiopatologia , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologiaRESUMO
ABSTRACT Objectives: Detection rate of thyroid nodules is increasing with the use of new imaging modalities, especially in screening for malignancies. Positron emission tomography/computed tomography (PET/ CT)-positive thyroid nodules should be differentiated for malignancy to avoid unnecessary operations and further follow-up. Most trials evaluate the role of SUVmax, but there is no definitive information about the utility of Hounsfield unit (HU) values for prediction of malignancy. This study aimed to evaluate the HU values beside SUVmax for detecting malignancy risk of PET/CT-positive thyroid nodules. Subjects and methods: Results of 98 cancer patients who had fine needle aspiration biopsy (FNAB) for thyroid nodules detected on PET/CT between January 2011 and December 2015 were assessed. The FNABs and surgical pathological results were recorded. Results: FNABs revealed benign results in 32 patients (32.7%), malignant in 18 (18.4%), non-diagnostic in 20 (20.4%), and indeterminate in 28 (28.5%). Twenty-four patients underwent thyroidectomy. The mean HU values were not significantly different in benign and malignant nodules (p = 0.73). However, the mean SUVmax was significantly higher (p < 0.001) in malignant ones. Area under curve (AUC) was 0.824 for SUVmax; the cut-off value was over 5.55 (p < 0.001), with 80% sensitivity, 84.5% specificity. Conclusions: Our current study demonstrated that HU value does not add any additional valuable information for discriminating between malignant and benign thyroid nodules. We also defined a SUV cut-off value of 5.55 for malignant potential of thyroid nodules detected on PET/CT Arch Endocrinol Metab. 2018;62(4):460-5