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BACKGROUND: Neuropsychiatric sequelae of COVID-19 have been widely documented in patients with severe neurological symptoms during the chronic or subacute phase of the disease. However, it remains unclear whether subclinical changes in brain metabolism can occur early in the acute phase of the disease. The aim of this study was to identify and quantify changes in brain metabolism in patients hospitalized for acute respiratory syndrome due to COVID-19 with no or mild neurological symptoms. RESULTS: Twenty-three non-intubated patients (13 women; mean age 55.5 ± 12.1 years) hospitalized with positive nasopharyngeal swab test (RT-PCR) for COVID-19, requiring supplemental oxygen and no or mild neurological symptoms were studied. Serum C-reactive protein measured at admission ranged from 6.43 to 189.0 mg/L (mean: 96.9 ± 54.2 mg/L). The mean supplemental oxygen demand was 2.9 ± 1.4 L/min. [18F]FDG PET/CT images were acquired with a median of 12 (4-20) days of symptoms. After visual interpretation of the images, semiquantitative analysis of [18F]FDG uptake in multiple brain regions was evaluated using dedicated software and the standard deviation (SD) of brain uptake in each region was automatically calculated in comparison with reference values of a normal database. Evolutionarily ancient structures showed positive SD mean values of [18F]FDG uptake. Lenticular nuclei were bilaterally hypermetabolic (> 2 SD) in 21/23 (91.3%) patients, and thalamus in 16/23 (69.6%), bilaterally in 11/23 (47.8%). About half of patients showed hypermetabolism in brainstems, 40% in hippocampi, and 30% in cerebellums. In contrast, neocortical regions (frontal, parietal, temporal and occipital lobes) presented negative SD mean values of [18F]FDG uptake and hypometabolism (< 2 SD) was observed in up to a third of patients. Associations were found between hypoxia, inflammation, coagulation markers, and [18F]FDG uptake in various brain structures. CONCLUSIONS: Brain metabolism is clearly affected during the acute phase of COVID-19 respiratory syndrome in neurologically asymptomatic or oligosymptomatic patients. The most frequent finding is marked hypermetabolism in evolutionary ancient structures such as lenticular nucleus and thalami. Neocortical metabolism was reduced in up to one third of patients, suggesting a redistribution of brain metabolism from the neocortex to evolutionary ancient brain structures in these patients.
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INTRODUCTION: Parkinsonism is now recognized as an additional feature in RFC1/CANVAS syndrome; however, no systematic evaluation of nigrostriatal dopaminergic function has been published so far. METHODS: This is an observational, single-center study, which analyzed 13 patients with molecular confirmation of RFC1/CANVAS. Disease severity was assessed with the SARA scale. Each subject was carefully evaluated for the presence of parkinsonian features. Dopamine transporter (DAT) imaging was acquired and reconstructed in the transverse, coronal and sagittal planes 4 h after venous injection of 99mTc-TRODAT-1. An experienced nuclear physician performed the visual analysis of all images. RESULTS: Patients had a mean age of 62.3 ± 8.8 years, and there were 9 women. The mean SARA score was 15.5 ± 5.8. Nine patients had abnormal DAT imaging results. The putamen was more frequently affected than the caudate nucleus on both sides. Considering all regions, uptake of 99mTc-TRODAT-1 did not correlate with disease duration or SARA scores. Parkinsonism was noticed in 3/13 patients, all of which had abnormal DAT scans. Interestingly, six subjects had reduced DAT imaging uptake, but no clinical signs of parkinsonism. CONCLUSION: Nigrostriatal dysfunction is frequent in RFC1/CANVAS even in the absence of clinical parkinsonism and may occur early in the disease course.
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INTRODUCTION: Computed tomography angiography (CTA) and ventilation/perfusion (V/Q) single photon emission computed tomography/CT (SPECT/CT) images have been widely used to detect PE, but few studies have performed a direct comparison between them. We aimed to evaluate the performance of these tests in the same group of patients, selected from the routine practice of a general hospital. METHODS: Patients with suspected acute PE were prospectively submitted to CTA and V/Q SPECT/CT. General radiologists and nuclear physicians, respectively, interpreted the images. Data regarding age, sex, time between examinations, symptoms, and Wells score were also recorded. The final diagnosis was decided through a consensus among the clinicians, taking into account clinical, laboratory, follow-up, and all imaging procedures data. RESULTS: Twenty-eight patients (15 male, 13 female, and median age of 51.5 years) were studied. Median duration of the onset of symptoms was 4 (1-14) days, and the median Wells score was 3.5 (1.5-6). Sensitivity, specificity, positive and negative predictive values, and accuracy were 84.6%, 80.0%, 78.6%, 85.7%, and 82.1% for V/Q SPECT/CT, and 46.1%, 100%, 100%, 68.2%, and 75.0% for CTA. The overall agreement between the methods was 57.1%. Of the 22 patients with negative CTA, 10 (45.4%) had positives V/Q SPECT/CT and seven of them classified as true positives. CONCLUSIONS: Our results suggest that V/Q SPECT/CT is more sensitive and accurate than CTA when interpreted by general radiologists and nuclear medicine physicians.
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Tomografia Computadorizada Multidetectores , Embolia Pulmonar , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Relação Ventilação-Perfusão , Embolia Pulmonar/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Angiografia , Doença Aguda , PerfusãoRESUMO
ABSTRACT Introduction: Prostate cancer (PC) is the second most commonly diagnosed cancer in males. 68Ga-PSMA PET/CT, a non-invasive diagnostic tool to evaluate PC with prostate-specific membrane antigen (PSMA) expression, has emerged as a more accurate alternative to assess disease staging. We aimed to identify predictors of positive 68Ga-PSMA PET and the accuracy of this technique. Materials and methods: Diagnostic accuracy cross-sectional study with prospective and retrospective approaches. We performed a comprehensive literature search on PubMed, Cochrane Library, and Embase database in search of studies including PC patients submitted to radical prostatectomy or radiotherapy with curative intent and presented biochemical recurrence following ASTRO 1996 criteria. A total of 35 studies involving 3910 patients submitted to 68-Ga-PSMA PET were included and independently assessed by two authors: 8 studies on diagnosis, four on staging, and 23 studies on restaging purposes. The significance level was α=0.05. Results: pooled sensitivity and specificity were 0.90 (0.86-0.93) and 0.90 (0.82-0.96), respectively, for diagnostic purposes; as for staging, pooled sensitivity and specificity were 0.93 (0.86-0.98) and 0.96 (0.92-0.99), respectively. In the restaging scenario, pooled sensitivity and specificity were 0.76 (0.74-0.78) and 0.45 (0.27-0.58), respectively, considering the identification of prostate cancer in each described situation. We also obtained specificity and sensitivity results for PSA subdivisions. Conclusion: 68Ga-PSMA PET provides higher sensitivity and specificity than traditional imaging for prostate cancer.
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Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia Computadorizada por Raios X , Estudos Transversais , Estudos Prospectivos , Estudos Retrospectivos , Compostos Radiofarmacêuticos , Tomografia por Emissão de PósitronsRESUMO
INTRODUCTION: Prostate cancer (PC) is the second most commonly diagnosed cancer in males. 68Ga-PSMA PET/CT, a non-invasive diagnostic tool to evaluate PC with prostate-specific membrane antigen (PSMA) expression, has emerged as a more accurate alternative to assess disease staging. We aimed to identify predictors of positive 68Ga-PSMA PET and the accuracy of this technique. MATERIALS AND METHODS: Diagnostic accuracy cross-sectional study with prospective and retrospective approaches. We performed a comprehensive literature search on PubMed, Cochrane Library, and Embase database in search of studies including PC patients submitted to radical prostatectomy or radiotherapy with curative intent and presented biochemical recurrence following ASTRO 1996 criteria. A total of 35 studies involving 3910 patients submitted to 68-Ga-PSMA PET were included and independently assessed by two authors: 8 studies on diagnosis, four on staging, and 23 studies on restaging purposes. The significance level was α=0.05. RESULTS: pooled sensitivity and specificity were 0.90 (0.86-0.93) and 0.90 (0.82-0.96), respectively, for diagnostic purposes; as for staging, pooled sensitivity and specificity were 0.93 (0.86-0.98) and 0.96 (0.92-0.99), respectively. In the restaging scenario, pooled sensitivity and specificity were 0.76 (0.74-0.78) and 0.45 (0.27-0.58), respectively, considering the identification of prostate cancer in each described situation. We also obtained specificity and sensitivity results for PSA subdivisions. CONCLUSION: 68Ga-PSMA PET provides higher sensitivity and specificity than traditional imaging for prostate cancer.
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Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata , Estudos Transversais , Humanos , Masculino , Tomografia por Emissão de Pósitrons , Estudos Prospectivos , Neoplasias da Próstata/diagnóstico por imagem , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
Many efforts have been made to standardize the interpretation of 18F-FDG PET/CT in multiple myeloma (MM) with qualitative visual analysis or with quantitative metabolic parameters using various methods for lesion segmentation of PET images. The aim of this study was to propose a quantitative method for bone and bone marrow evaluation of 18F-FDG PET/CT considering the extent and intensity of bone 18F-FDG uptake: Intensity of Bone Involvement (IBI). Whole body 18F-FDG PET/CT of 59 consecutive MM patients were evaluated. Compact bone tissue was segmented in PET images using a global threshold for HU of the registered CT image. A whole skeleton mask was created and the percentage of its volume with 18F-FDG uptake above hepatic uptake was calculated (Percentage of Bone Involvement - PBI). IBI was defined by multiplying PBI by mean SUV above hepatic uptake. IBI was compared with visual analysis performed by two experienced nuclear medicine physicians. IBI calculation was feasible in all images (range:0.00-1.35). Visual analysis categorized PET exams into three groups (negative/mild, moderate and marked bone involvement), that had different ranges of IBI (multi comparison analysis, p < 0.0001). There was an inverse correlation between the patients' hemoglobin values and IBI (r = -0.248;p = 0.02). IBI score is an objective measure of bone and bone marrow involvement in MM, allowing the categorization of patients in different degrees of aggressiveness of the bone disease. The next step is to validate IBI in a larger group of patients, before and after treatment and in a multicentre setting.
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Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Fluordesoxiglucose F18 , Mieloma Múltiplo/diagnóstico por imagem , Mieloma Múltiplo/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Osso e Ossos/metabolismo , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Mieloma Múltiplo/metabolismo , Osteólise , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons , Compostos RadiofarmacêuticosRESUMO
AIMS: To assess the validity of an online method to quantitatively evaluate cerebral hypometabolism in patients with pharmacoresistant focal epilepsy as a complement to the visual analysis of the 18F-FDG positron emission tomography (PET)/CT exam. METHODS: A total of 39 patients with pharmacoresistant epilepsy and probable focal cortical dysplasia [22 patients with frontal lobe epilepsy (FLE) and 17 with temporal lobe epilepsy (TLE)] underwent a presurgical evaluation including EEG, video-EEG, MRI, and 18F-FDG PET/CT. We conducted the automated quantification of their 18F-FDG PET/CT data and compared the results with those of the visual-PET analysis conducted by experienced nuclear medicine physicians. For each patient group, we calculated Cohen's Kappa coefficient for the visual and quantitative analyses, as well as each method's sensitivity, specificity, and positive and negative predictive values. RESULTS: For the TLE group, both the visual and quantitative analyses showed high agreement. Thus, although the quantitative analysis could be used as a complement, the visual analysis on its own was consistent and precise. For the FLE group, on the other hand, the visual analysis categorized almost half of the cases as normal, revealing very low agreement. For those patients, the quantitative analysis proved critical to identify the focal hypometabolism characteristic of the epileptogenic zone. Our results suggest that the quantitative analysis of 18F-FDG PET/CT data is critical for patients with extratemporal epilepsies, and especially those with subtle MRI findings. Furthermore, it can easily be used during the routine clinical evaluation of 18F-FDG PET/CT exams. SIGNIFICANCE: Our results show that quantification of 18F-FDG PET is an informative complementary method that can be added to the routine visual evaluation of patients with subtle lesions, particularly those in the frontal lobes.
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OBJECTIVE: The aim of this study was to assess clinical features and colonic transit patterns in Brazilian children with refractory constipation.METHODS: From 2010 to 2013, 79 constipated patients received follow-up care in a tertiary hospital. Of these patients, 28 (aged 8-14 years) were refractory to conventional therapy and underwent a simplified visual method of nuclear colonic transit study, by ingestion of a liquid meal containing 9.25 MBq/kg of 99mTc-phytate. Abdominal static images were taken immediately and at two, six, 24, 30, and 48 h after ingestion for qualitative analysis of the radio marker progression through the colon.RESULTS: Two patterns of colonic transit were found: slow colonic transit (SCT,n = 14), when images at 48 h showed a larger part of the tracer remained in proximal and transverse colon, and distal retention (DR, n = 14), when after 30 h, the radio isotope passed the transverse colon and was retained in the rectosigmoid up to 48 h. The SCT and DR group included, respectively, nine and ten males; median ages in the nuclear study of 11 and 10 years, p = 0.207; median duration of constipation of seven and six years, p = 0.599. Constipation appearing during first year age (p = 0.04) and report of soft stools (p = 0.02) were more common in SCT patients. Palpable abdominal fecal impaction was found only in DR group. Appendicostomy for antegrade continence enema was successful in 4/12 (30%) of SCT patients (median follow-up: 2.4 years).CONCLUSION: Nuclear transit study distinguished two colonic dysmotility patterns and was useful for guiding refractory patients to specific therapies.
OBJETIVO: Avaliar as características clínicas e os padrões de trânsito intestinal em crianças brasileiras com constipação refratária.MÉTODOS: De 2010 a 2013, 79 pacientes constipados receberam acompanhamento em um hospital terciário. Desses pacientes, 28 (entre 8-14 anos) foram identificados como terapia refratária a convencional e passaram por um método visual simplificado de estudo nuclear do trânsito intestinal, com ingestão de uma refeição líquida contendo 9,25 MBq/Kg de fitato-99mTc. Imagens estáticas abdominais foram tiradas imediatamente e em duas, seis, 24, 30 e 48 horas após a ingestão para uma análise qualitativa da progressão do marcador radioativo pelo cólon.RESULTADOS: Foram encontrados dois padrões de trânsito intestinal: trânsito intestinal lento (STC, n = 14), quando as imagens de 48 horas mostraram que grande parte do marcador permaneceu no cólon proximal e transversal; e retenção distal (DR, n = 14), quando, após 30 horas, o radioisótopo havia passado o cólon transverso e estava retido no retossigmoide até 48 horas. O grupo STC e o grupo DR incluíram, respectivamente, nove e 10 meninos; idade média no momento do NTS: 11 e 10 anos, p = 0,207; duração média de constipação: sete e seis anos, p = 0,599. Sintomas de constipação durante o primeiro ano de idade (p = 0,04) e relatos de fezes moles (p = 0,02) foram mais comuns em pacientes com STC. Observou-se impactação fecal abdominal palpável apenas no grupo DR. A apendicostomia para enema anterógrado para continência foi bem-sucedida em 4/12 (305) pacientes com STC (acompanhamento médio: 2,4 anos).CONCLUSÃO: O estudo nuclear do trânsito diferenciou dois padrões de dismotilidade intestinal e foi útil para orientar pacientes refratários a terapias específicas.
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Adolescente , Criança , Feminino , Humanos , Masculino , Colo/fisiopatologia , Constipação Intestinal/fisiopatologia , Trânsito Gastrointestinal , Doença Crônica , Colo , Constipação Intestinal , Impacção FecalRESUMO
OBJECTIVE: The aim of this study was to assess clinical features and colonic transit patterns in Brazilian children with refractory constipation. METHODS: From 2010 to 2013, 79 constipated patients received follow-up care in a tertiary hospital. Of these patients, 28 (aged 8-14 years) were refractory to conventional therapy and underwent a simplified visual method of nuclear colonic transit study, by ingestion of a liquid meal containing 9.25 MBq/kg of (99m)Tc-phytate. Abdominal static images were taken immediately and at two, six, 24, 30, and 48h after ingestion for qualitative analysis of the radio marker progression through the colon. RESULTS: Two patterns of colonic transit were found: slow colonic transit (SCT, n=14), when images at 48h showed a larger part of the tracer remained in proximal and transverse colon, and distal retention (DR, n=14), when after 30h, the radio isotope passed the transverse colon and was retained in the rectosigmoid up to 48h. The SCT and DR group included, respectively, nine and ten males; median ages in the nuclear study of 11 and 10 years, p=0.207; median duration of constipation of seven and six years, p=0.599. Constipation appearing during first year age (p=0.04) and report of soft stools (p=0.02) were more common in SCT patients. Palpable abdominal fecal impaction was found only in DR group. Appendicostomy for antegrade continence enema was successful in 4/12 (30%) of SCT patients (median follow-up: 2.4 years). CONCLUSION: Nuclear transit study distinguished two colonic dysmotility patterns and was useful for guiding refractory patients to specific therapies.
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Colo/fisiopatologia , Constipação Intestinal/fisiopatologia , Trânsito Gastrointestinal , Adolescente , Criança , Doença Crônica , Colo/diagnóstico por imagem , Constipação Intestinal/diagnóstico por imagem , Impacção Fecal/diagnóstico por imagem , Feminino , Humanos , Masculino , CintilografiaRESUMO
PURPOSE: Bone scintigraphy (BS) has been used extensively for many years for the diagnosis of bone metastases despite its low specificity and significant rate of equivocal lesions. (18)F-Fluoride PET/CT has been proven to have a high sensitivity and specificity in the detection of malignant bone lesions, but its effectiveness in patients with inconclusive lesions on BS is not well documented. This study evaluated the ability of (18)F-fluoride PET/CT to exclude bone metastases in patients with various malignant primary tumours and nonspecific findings on BS. METHODS: We prospectively studied 42 patients (34-88 years of age, 26 women) with different types of tumour. All patients had BS performed for staging or restaging purposes but with inconclusive findings. All patients underwent (18)F-fluoride PET/CT. All abnormalities identified on BS images were visually compared with their appearance on the PET/CT images. RESULTS: All the 96 inconclusive lesions found on BS images of the 42 patients were identified on PET/CT images. (18)F-Fluoride PET/CT correctly excluded bone metastases in 23 patients (68 lesions). Of 19 patients (28 lesions) classified by PET/CT as having metastases, 3 (5 lesions) were finally classified as free of bone metastases on follow-up. The sensitivity, specificity, and positive and negative predictive values of (18)F-fluoride PET/CT were, respectively, 100 %, 88 %, 84 % and 100 % for the identification of patients with metastases (patient analysis) and 100 %, 82 % and 100 % for the identification of metastatic lesions (lesion analysis). CONCLUSION: The factors that make BS inconclusive do not affect (18)F-fluoride PET/CT which shows a high sensitivity and negative predictive value for excluding bone metastases even in patients with inconclusive conventional BS.
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Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Fluordesoxiglucose F18 , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
PURPOSE: To investigate the factors influencing the success rate in a fixed, 15 mCi approach for treatment of Graves' hyperthyroidism. MATERIAL AND METHODS: The thyroid function outcome (hyperthyroidism or euthyroidism/hypothyroidism) was verified at least 1 year after radioiodine therapy (RIT) retrospectively and compared with presenting clinical characteristics and pre-RIT parameters in 87 patients treated with I-iodide for Graves' disease in a tertiary care center. RESULTS: After RIT, 16 patients (18.4%) became euthyroid, 54 patients (62.1%) became hypothyroid, and 17 (19.5%) remained hyperthyroid. We found no statistically significant association between thyroid function outcome and gender (P = 0.50), ophthalmopathy (P = 0.69), drug used (methimazole or propylthiouracil; P = 1.00), maintenance or withdrawal of thionamides pre-RIT (P = 0.98), or 99mTc sodium pertechnetate thyroid uptake prior to RIT (P = 0.75). The only variable associated with the success rate was thyroid mass <62 g (P < 0.001). CONCLUSIONS: Our study has shown that a fixed 15 mCi approach for treatment of Graves' disease was effective, but high failure rates were observed in patients presenting larger goiters, particularly those with estimated thyroid mass >62 g.
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Doença de Graves/radioterapia , Adolescente , Adulto , Idoso , Feminino , Doença de Graves/patologia , Humanos , Radioisótopos do Iodo/uso terapêutico , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão/efeitos da radiação , Estudos Retrospectivos , Glândula Tireoide/patologia , Glândula Tireoide/efeitos da radiação , Falha de Tratamento , Adulto JovemRESUMO
OBJECTIVE: Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). SUBJECTS AND METHODS: The probability of progressive disease according to CDs was evaluated in patients < 45 years old and > 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. RESULTS: At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p < 0.0001), higher TNM stages (p < 0.0001), and follicular carcinomas (p = 0.0034). Probability of disease progression was higher with CDs > 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. CONCLUSION: Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.
OBJETIVO: Avaliar a eficácia de doses cumulativas (DCs) da terapia com iodeto-131I (RIT) no câncer diferenciado de tiroide (CDT). SUJEITOS E MÉTODOS: A probabilidade de doença em progressão conforme a DC foi calculada em pacientes com idade < 45 e > 45 anos e correlacionada com o TNM, valores de tiroglobulina sérica, tipos histológicos e variantes, idade e tempo de doença. RESULTADOS: Ao final de um seguimento de 69 ± 56 meses, 85 dos 150 pacientes CDT submetidos a doses fixas de RIT não tinham evidência de doença, 47 tinham doença estável e 18, doença progressiva. DCs mais elevadas foram usadas nas variantes agressivas (p < 0,0001), maior estágio TNM (p < 0,0001) e nos carcinomas foliculares (p = 0,0034). A probabilidade de doença em progressão foi maior com DCs > 600 mCi em pacientes > 45 anos e com DCs > 800 mCi em pacientes < 45 anos. CONCLUSÃO: Apesar de alguns pacientes ainda responderem a altas DCs, o impacto de RITs deve ser cuidadosamente avaliado e outras estratégias terapêuticas devem ser consideradas.
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Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Papilar/radioterapia , Radioisótopos do Iodo/administração & dosagem , Neoplasias da Glândula Tireoide/radioterapia , Carcinoma Papilar/metabolismo , Carcinoma Papilar/secundário , Progressão da Doença , Relação Dose-Resposta à Radiação , Métodos Epidemiológicos , Radioisótopos do Iodo/efeitos adversos , Resultado do TratamentoRESUMO
OBJECTIVE: To evaluate the utility of diuretic dynamic renal scintigraphy (DDRS) with technetium-99m-L,L-ethylenedicysteine ((99m)Tc-EC) in patients with indeterminate or possible false-positive results for urinary obstruction by technetium-99m diethylenetriamine penta-acetic acid ((99m)Tc-DTPA) DDRS. METHODS: A total of 92 patients (63 male; mean age, 16.6 +/- 21.25 years) were studied, with a total of 103 kidneys presenting indeterminate (20/103) or possible false-positive results for obstruction attributable to reduced renal function or severe kidney dilation (83/103) by (99m)Tc-DTPA DDRS (<60% of radiopharmaceutical excreted in 20 minutes-half-time clearance [T(1/2)] >15 minutes). Patients were reimaged after intravenous injection of (99m)Tc-EC, with dynamic images before and after furosemide administration using the same acquisition parameters applied in the previous (99m)Tc-DTPA study. Time interval between (99m)Tc-DTPA and (99m)Tc-EC renograms was 2-64 days. The percentage of excreted material 20 minutes after furosemide was calculated using both radiopharmaceuticals, and were statistically compared using the paired samples t test. RESULTS: The excretion after furosemide injection was 25.3% +/- 18.2% for (99m)Tc-DTPA and 41.2% +/- 26.1% for (99m)Tc-EC, with a statistically significant difference between both radiopharmaceuticals (P <.0001). Using (99m)Tc-EC obstruction was excluded in 36 of 103 kidneys, which excreted >60%. A total of 10 of 83 kidneys (12.0%) with an obstructive pattern by (99m)Tc-DTPA study turned out to be indeterminate by (99m)Tc-EC DDRS. There was an agreement between (99m)Tc-EC and (99m)Tc-DTPA studies in 54 of 83 kidneys with obstructive (65.1%) and in 3 of 20 (15.0%) with indeterminate patterns. CONCLUSIONS: (99m)Tc-EC was more effective than (99m)Tc-DTPA for excluding obstruction, presenting less false-positive and indeterminate results. (99m)Tc-EC can substitute (99m)Tc-DTPA to evaluate patients with urinary tract dilation.
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Cisteína/análogos & derivados , Pelve Renal , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Pentetato de Tecnécio Tc 99m , Obstrução Ureteral/diagnóstico por imagem , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Dilatação Patológica , Reações Falso-Positivas , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Cintilografia , Adulto JovemRESUMO
OBJECTIVE: Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). SUBJECTS AND METHODS: The probability of progressive disease according to CDs was evaluated in patients < 45 years old and > 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. RESULTS: At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p < 0.0001), higher TNM stages (p < 0.0001), and follicular carcinomas (p = 0.0034). Probability of disease progression was higher with CDs > 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. CONCLUSION: Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.
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Carcinoma Papilar/radioterapia , Radioisótopos do Iodo/administração & dosagem , Neoplasias da Glândula Tireoide/radioterapia , Carcinoma Papilar/metabolismo , Carcinoma Papilar/secundário , Progressão da Doença , Relação Dose-Resposta à Radiação , Métodos Epidemiológicos , Feminino , Humanos , Radioisótopos do Iodo/efeitos adversos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Unilateral destructive brain lesions of early development can result in compensatory thickening of the ipsilateral cranial vault. The aim of this study was to determine the frequency of these bone changes among patients with epilepsy and precocious destructive lesions, and whether a relationship exists between these changes and epileptiform discharges lateralization. Fifty-one patients had their ictal / interictal scalp EEG and skull thickness symmetry on MRI analyzed. Patients were divided into three main groups according to the topographic distribution of the lesion on the MRI: hemispheric (H) (n=9); main arterial territory (AT) (n=25); arterial borderzone (Bdz) (n=17). The EEG background activity was abnormal in 26 patients and were more frequent among patients of group H (p= 0.044). Thickening of the skull was more frequent among patients of group H (p= 0.004). Five patients (9.8%) showed discordant lateralization between epileptiform discharges and structural lesion (four of them with an abnormal background, and only two of them with skull changes). In one of these patients, ictal SPECT provided strong evidence for scalp EEG false lateralization. The findings suggest that compensatory skull thickening in patients with precocious destructive brain insults are more frequent among patients with unilateral and large lesions. However, EEG lateralization discordance among these patients seems to be more related to EEG background abnormalities and extent of cerebral damage than to skull changes.
Assuntos
Encéfalo/patologia , Epilepsia/patologia , Crânio/patologia , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/patologia , Infarto Encefálico/fisiopatologia , Eletroencefalografia , Epilepsia/diagnóstico por imagem , Epilepsia/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Crânio/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Lesões cerebrais destrutivas unilaterais ocorridas em fase precoce do desenvolvimento podem resultar em espessamento compensatório da calota craniana ipsilateral. O objetivo deste estudo foi determinar a freqüência destas alterações ósseas em pacientes com epilepsia e lesões destrutivas precoces e avaliar se há associação entre estas alterações e lateralização de descargas epileptiformes. Foram analisados EEGs interictais / ictais e espessura do crânio pela RM de 51 pacientes. Os pacientes foram divididos em três grupos de acordo com a distribuição topográfica da lesão à RM: hemisférico (H) (n=9); território arterial (AT) (n=25); fronteira arterial (Bdz) (n=17). A atividade de base no EEG foi anormal em 26 pacientes e foi mais freqüente entre os pacientes do grupo H (p=0,044). Espessamento unilateral da calota craniana foi mais freqüente entre os pacientes do grupo H (p=0,004). Cinco pacientes (9,8 por cento) apresentaram discordância lateralizatória entre as descargas epileptiformes e lesão estrutural (quatro deles com atividade de base anormal, e apenas dois deles com espessamento da calota craniana). Em um destes pacientes, o SPECT ictal revelou forte evidência de falsa lateralização pelo EEG. Os achados sugerem que o espessamento compensatório da calota craniana é mais freqüente entre pacientes com lesões unilaterais e extensas. No entanto, a lateralização de descargas epileptiformes parece estar mais relacionada ao grau de alteração da atividade de base e extensão da lesão cerebral do que às alterações ósseas.