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BACKGROUND: We aimed to describe orbital positron emission tomography/computed tomography (PET/CT) imaging findings, both structural and metabolic, in different clinical stages of Graves ophthalmopathy (GO). This prospective, observational, cross-sectional study examined 32 eyes of 16 patients with GO. METHODS: Patients were assessed with a complete ophthalmological evaluation and assigned a VISA classification for GO. All patients underwent serum thyroid hormone measurement, antibody profile, and 18-fluorodeoxyglucose positron emission tomography/computed tomography (18-FDG PET/CT) of the orbits. The 18-FDG uptake on PET images was expressed in terms of maximum standard uptake value (SUVmax). CT images were analyzed, and orbital structures were measured in millimeters. Vision, inflammation, strabismus, and overall appearance were assessed according to the VISA classification system, thyroid hormone levels, antibody values, 18-FDG uptake, and thickness of orbital structures. RESULTS: Altogether, 32 eyes of 16 patients (10 women, 6 men; mean age 44.31 ± 13 years, range 20-71 years) were included. Three patients were hypothyroid, seven were euthyroid, and six were hyperthyroid. CT measurements of extraocular muscle diameter were elevated (P < 0.05), and muscle 18-FDG uptake values were increased. Eyes with a clinical VISA inflammation score of ≤ 4 had an average extraocular muscle SUVmax of 3.09, and those with a score of ≥ 5 had an average SUVmax of 3.92 (P = 0.09), showing no clear correlation between clinically observed inflammation and 18-FDG uptake. 18-FDG uptake values also did not show a correlation with extraocular muscle diameter as measured by CT (R2 = 0.0755, P > 0.05). CONCLUSIONS: We demonstrated a lack of correlation between 18-FDG extraocular muscle uptake and either clinical inflammation score or muscle diameter. Although 18-FDG uptake has been used as an inflammation marker in other pathologies, inflammation in GO may be clinically detected in PET/CT-negative cases, and cases with negative clinical findings may show inflammation on PET/CT. Clinical evaluation is mandatory but may be insufficient and inaccurate for classifying GO. A larger and homogeneous sample size and further research is needed to define the role of PET/CT in detecting, grading, and follow-up of GO to optimize treatment of the inflammatory stage respect clinical methods currently used.
Assuntos
Oftalmopatia de Graves/diagnóstico , Órbita/patologia , Glândula Tireoide/fisiopatologia , Adulto , Idoso , Estudos Transversais , Feminino , Fluordesoxiglucose F18/metabolismo , Oftalmopatia de Graves/sangue , Oftalmopatia de Graves/patologia , Oftalmopatia de Graves/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Estudos Prospectivos , Índice de Gravidade de Doença , Glândula Tireoide/metabolismo , Hormônios Tireóideos/sangue , Tomografia Computadorizada por Raios XRESUMO
Objective. To compare 18-fluorodeoxyglucose (FDG) uptake by positron emission tomography (PET) in extraocular muscles (EOMs) of patients with Graves' ophthalmopathy (GO) versus patients without GO. Design. Prospective, observational, comparative, and cross-sectional study. Participants. Thirty-two eyes of patients with GO and seventy eyes of patients without GO. Methods. We prospectively included patients older than 18 years of age with and without GO. FDG-PET imaging study was performed; standardized unit value (SUVmax) was quantified in EOMs. Standard deviation and significant statistical difference (P < 0.05) were calculated. Results. Thirty-two eyes of sixteen patients of the GO group were included, with a mean age of 44.31 (20-71) years. Seventy eyes of thirty-five patients of the group without GO were included, with a mean age of 49.20 (24-77) years. EOMs average uptake of the groups with and without GO were 3.38 ± 1.31 and 1.89 ± 0.51 SUVmax (P < 0.05), respectively. Conclusion. FDG uptake was significantly increased in EOMs of patients with GO. PET gives valuable information and may be a helpful tool in detecting, localizing, and quantifying GO inflammation. Further research is needed to define the role of PET in detecting, grading, and following up GO in order to optimize treatment in the inflammatory stage.
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OBJECTIVE: To evaluate the role of PET and MRI fused image study inpatients with primary brain tumors previously treated, to determine the presence of radionecrosis vs residual tumor viability. METHODS: Primary brain tumors were diagnosed by biopse and MR. 18FDG-PET scan and T1 enhanced MRI follow-up studies were performed between 3 and 5 months after treatment. The 18F-FDG uptake was semiquantitavively calculated by a region-of-interest based Tumor hotspot/normal brain tissue index. RESULTS: Fifty-seven patients were studied, 37 had high grade gliomas; 9 had oligoastrocytomas; 5 had Embrionary tumors; I had a meningyoma and I had an oliodendroglial tumor. All MR studies showed tumor enhancement, without determine wether if it was radionecrosis or tumor viability. PET/MR fused study diagnosed 21 negative studies (30%) and 36 positive results (70%). Tumor hotspot/normal brain tissue index correlated well with the visual analysis registered. CONCLUSIONS: Visual analysis in the contrast enhanced MR overestimates the tumoral area, without defining a possible diagnosis between tumor viability and radionecrosis. Metabolic activity in the 18F-FDG PET study in the enhanced area, determines the presence of residual tumor viability. Therefore, coregistration can be used to obtain a more specific diagnosis optimizing the cinical use.
Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico , Fluordesoxiglucose F18 , Glioma/diagnóstico por imagem , Glioma/diagnóstico , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Adolescente , Adulto , Idoso , Interpretação Estatística de Dados , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Necrose , Lesões por Radiação/diagnóstico , Lesões por Radiação/diagnóstico por imagemRESUMO
Objetivo: Determinar la efectividad del co-registro de imágenes PET/RM (tomografía de emisión de positrones y resonancia magnética) en el diagnóstico de recidiva tumoral vs.. radionecrosis en pacientes con patología tumoral cerebral primaria previamente tratados. Material y métodos: El diagnóstico de tumor cerebral se determinó por RM e histopatología. Después de 3 a 5 meses postratamiento se realizó RM y PET como parte del seguimiento. El análisis de dichas imágenes se hizo de manera visual y semicuantitativa mediante la obtención de un índice de captación de 18F-FDG de tejido tumoral/ tejido cerebral sano. Resultados: Se estudiaron 57 pacientes; un total de 37 gliomas astrocíticos, 9 gliomas mixtos, 5 tumores embrionarios, 1 tumor meníngeo y 1 tumor oligodendroglial . Todas las imágenes de RM presentaban áreas de reforzamiento, dejando sospecha entre radionecrosis o viabilidad tumoral; con el co-registro PET/RM se diagnosticaron 21 estudios negativos (30 %) y 36 positivos (70 %). El índice tejido tumoral/tejido cerebral sano se correlacionó adecuadamente con los resultados visuales obtenidos. Conclusión: La RM sobreestima el área tumoral a valorar. La presencia de la actividad metabólica analizada mediante PET sobre las áreas de reforzamiento por RM permite determinar la presencia de viabilidad tumoral. Esto aumenta la certeza diagnóstica de ambas técnicas de imagen.
OBJECTIVE: To evaluate the role of PET and MRI fused image study inpatients with primary brain tumors previously treated, to determine the presence of radionecrosis vs residual tumor viability. METHODS: Primary brain tumors were diagnosed by biopse and MR. 18FDG-PET scan and T1 enhanced MRI follow-up studies were performed between 3 and 5 months after treatment. The 18F-FDG uptake was semiquantitavively calculated by a region-of-interest based Tumor hotspot/normal brain tissue index. RESULTS: Fifty-seven patients were studied, 37 had high grade gliomas; 9 had oligoastrocytomas; 5 had Embrionary tumors; I had a meningyoma and I had an oliodendroglial tumor. All MR studies showed tumor enhancement, without determine wether if it was radionecrosis or tumor viability. PET/MR fused study diagnosed 21 negative studies (30%) and 36 positive results (70%). Tumor hotspot/normal brain tissue index correlated well with the visual analysis registered. CONCLUSIONS: Visual analysis in the contrast enhanced MR overestimates the tumoral area, without defining a possible diagnosis between tumor viability and radionecrosis. Metabolic activity in the 18F-FDG PET study in the enhanced area, determines the presence of residual tumor viability. Therefore, coregistration can be used to obtain a more specific diagnosis optimizing the cinical use.