RESUMEN
PURPOSE: 18F-DOPA Positron Emission Tomography/Computed Tomography (18F-DOPA PET/CT) is a sensitive functional imaging method (65-75%) for detecting disease localization in medullary thyroid cancer (MTC). We aimed: (i) to assess the clinical usefulness of 18F-DOPA PET/CT in patients with MTC and elevated calcitonin (Ctn) and CEA levels and, (ii) to evaluate changes in disease management secondary to the findings encountered with this methodology. METHODS: Thirty-six patients with MTC and Ctn levels ≥150 pg/ml were prospectively included. Neck ultrasound, chest contrast-enhanced CT, liver magnetic resonance imaging/abdominal three-phase contrast-enhanced CT and bone scintigraphy were carried out up to 6 months before the 18F DOPA PET/CT. RESULTS: Seventy eight percent of patients were female and 27% had hereditary MTC. Median Ctn level was 1450 pg/ml [150-56620], median CEA level 413 ng/ml [2.9-7436]. Median Ctn DT was 37.5 months [5.7-240]; median CEA DT was 31.8 [4.9-180]. 18F-DOPA PET/CT was positive in 33 patients (91.6%); in 18 (56%) uptake was observed in lymph nodes in the neck or mediastinum, in seven cases (22%) distant metastases were diagnosed, and in eight additional patients (24%) both locoregional and distant sites of disease were found. Ctn and CEA levels were higher in patients with ≥3 foci of distant metastases. In 14 patients (38.8%), findings on 18F-DOPA PET/CT led to changes in management; surgery for locoregional lymph nodes was the most frequent procedure in 8 patients (22%). CONCLUSION: 18F-DOPA PET/CT was useful for the detection of recurrent disease in MTC, providing incremental value over conventional imaging procedures that led to modification in treatment strategies in nearly 40% of patients.
Asunto(s)
Carcinoma Neuroendocrino , Neoplasias de la Tiroides , Calcitonina , Antígeno Carcinoembrionario , Carcinoma Neuroendocrino/patología , Dihidroxifenilalanina/análogos & derivados , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tomografía de Emisión de Positrones , Estudios Prospectivos , Neoplasias de la Tiroides/patologíaRESUMEN
Resumen La placenta y el hígado son los encargados del metabolismo de los carbohidratos. La glucosa es fundamental para el metabolismo cerebral. La hipoglucemia se define con valores < 47 mg/dl. La hipoglicemia que persiste más de 7 días se atribuye a problemas metabólicos o endocrinológicos y requiere un flujo de glucosa > 12 mg/kg/min para alcanzar normo-glicemia. La hipoglicemia hiperinsulinémica congénita persistente (HHCP) es poco común (1:50,000 nacidos vivos), es la causa más común de hipoglicemia persistente secundaria a una secreción inadecuada de insulina, que puede afectar el neurodesarrollo. Hay una forma difusa y una focal, con manifestaciones clínicas idénticas, pero con mecanismos patológicos diferentes. El tratamiento médico es a base de diazóxido y ocreótide. En el 95% de los casos no hay respuesta al tratamiento médico, requiriendo pancreatectomía subtotal. Se utilizó ocreótide y nifedipino. La tomografía computada con emisión de positrones (PET/TC 18F-DOPA) encontró incremento en la capación pancreática de insulina, se realizó pancreactectomía. Se egresó sin complicaciones y en seguimiento pediátrico sin alteraciones neurológicas.
Abstract The placenta and liver are responsible for the metabolism of carbohydrates. The glucose is fundamental for brain metabolism. Hypoglycaemia is defined as values < 47 mg/dl. Hypoglycaemia that persists for more than 7 days is attributed to metabolic or endocrine problems and requires glucose flow > 12 GKM to reach normoglycemia. Persistent congenital hyperinsulinemic hypoglycemia (PCHH) is uncommon (1:50,000 live births) is the most common cause of persistent hypoglycemia secondary to inadequate insulin secretion, can significantly affect neurodevelopment. There is a diffuse and a focal form, with identical clinical manifestations, but with different pathological mechanisms. The medical treatment is diazoxide and ocreotide. In 95% of cases there is no response to medical treatment, requiring subtotal pancreatectomy. Ocreotide and nifedipine were used. Positron emission computed tomography (PET/CT 18F-DOPA) found an increase in pancreatic insulin capacity, a pancreactectomy was performed. He was discharged without complications and in pediatric follow-up without neurological alterations.
RESUMEN
BACKGROUND: Schizophrenia is a disease diagnosed by visible signs and symptoms from late adolescence to early adulthood. The etiology of this disease remains unknown. An objective diagnostic approach is required. Here, we used a mouse model that shows schizophrenia-like phenotypes to study brain glucose metabolism and presynaptic dopaminergic functioning by positron emission tomography (PET) and immunohistochemistry. PET scannings were performed on mice after the administration of [18F]-FDG or [18F]-F-DOPA. Glucose metabolism was evaluated in basal conditions and after the induction of a hyperdopaminergic state. RESULTS: Mutant animals show reduced glucose metabolism in prefrontal cortex, amygdala, and nucleus reuniens under the hyperdopaminergic state. They also show reduced [18F]-F-DOPA uptake in prefrontal cortex, substantia nigra reticulata, raphe nucleus, and ventral striatum but increased [18F]-F-DOPA uptake in dorsal striatum. Mutant animals also show reduced tyrosine hydroxylase expression on midbrain neurons. CONCLUSIONS: Dopamine D2 mutant animals show reduced glucose metabolism and impaired presynaptic dopaminergic functioning, in line with reports from human studies. This mouse line may be a valuable model of schizophrenia, useful to test novel tracers for PET scanning diagnostic.