RESUMO
OBJECTIVE: Thyroid findings or incidentalomas in (18)F-FDG PET/CT studies are relatively frequent, being its clinical significance subject of controversy. The aim of this study was to show our experience in the detection of thyroid incidentalomas by PET/CT studies as well as its follow up. MATERIAL AND METHODS: A retrospective and descriptive review was conducted on patients who had thyroid incidentalomas detected in (18)F-FDG PET/CT studies between June 2010 and March 2013. Patient's medical records were reviewed for age, genre, maximum standardized uptake value (SUVmax), thyroid diseases, TSH and antithyroid antibodies levels, ultrasound, fine-needle aspiration (FNA) and cytology. RESULTS: 4085 PET/CT studies for several purposes were performed. Eighty-three of these studies (2.03%) showed thyroid incidentalomas. Thirty-seven patients showed a diffuse increase of glucose metabolism in the thyroid gland and 46 showed a focal increase of glucose metabolism. Five out of 46 patients with focal uptake were diagnosed of a neoplastic disease by cytology (11%). The SUVmax of malignant pathology did not differ from that of benign thyroid diseases (Mean: 10,26 and 5,92 respectively). CONCLUSION: In our experience, focal thyroid incidentalomas detected in (18)F-FDG PET/CT studies are related to a significant risk of malignancy (11%). Therefore, in these situations, an ultrasound study with fine needle biopsy should be recommended. Moreover, a diffuse increase of glucose metabolism in the thyroid gland is often associated with benign thyroid pathology.
Assuntos
Neoplasias da Glândula Tireoide/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha Fina , Feminino , Fluordesoxiglucose F18 , Humanos , Achados Incidentais , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
Introducción. La Fluor-18 deoxiglucosa (18F-FDG) ha sido utilizada en múltiples estudios para determinar la tasa de utilización de la glucosa en condiciones normales y patológicas. Actualmente se sabe que en la insuficiencia cardiaca el patrón metabólico se encuentra alterado. Materiales y métodos Se realizó medición del metabolismo glucocídico en 4 portadores de miocardiopatía dilatada y en 3 sujetos sanos, todos bajo una carga de hidratos de carbono vía oral (75gr). Se adquirieron imágenes dinámicas de tórax. La captación miocárdica se estimó a partir de las curvas tiempo-actividad en aurícula y ventrículo izquierdo utilizando el análisis gráfico de Patlak. Resultados. Los siete pacientes estudiados son de sexo masculino. La tasa de captación de la 18F-FDG para el grupo de pacientes con miocardiopatía dilatada fue 1,31 +/- 0,2 versus 1,26 +/- 0,37 ml/100gr/min en el grupo control. Conclusión. La medición del metabolismo cardiaco de la glucosa por medio de 18F-FDG PET es posible de realizar en un servicio clínico, permitiendo de esta forma determinar la repercusión fisiológica y los cambios del metabolismo miocárdico en diversas enfermedades además de la evaluación de terapia.
Introduction. Fluorine18 deoxyglucose (18F-FDG) has been used in numerous studies to determine the cardiac rate of glucose metabolism in normal and pathological conditions. It is known that during heart failure the metabolic pattern is altered. Patlacks graphical analysis allows the assessment of heart muscle glucose consumption in patients with non-ischaemic heart failure and normal subjects. Methods. Standardized measurement of glucose metabolism was performed in four patients with dilated cardiomyopathy and three healthy subjects. All subjects received an oral load of carbohydrates (75gr) previous to scanning. Dynamic images of the thorax were acquired. Myocardial uptake was estimated from time-activity curves in the atrium and left ventricle using Patlacks graphical analysis. Results. All subjects studied were male. 18F-FDG uptake rate for the group with dilated cardiomyopathy was 1.31 +/-0.2, versus 1.26 +/- 0.37 ml/100gr/min in the control group. Conclusion. Measurement of cardiac glucose metabolism by 18F-FDG PET is feasible in a clinical service, allowing impact evaluation of physiologic and metabolic changes in the myocardium in different pathologic scenarios in addition to therapy assessment.