RESUMO
Resumen La heterotopia subcortical en banda (HSB) se refiere a la presencia de bandas lisas bilaterales de sustancia gris cerebral ubicadas en la sustancia blanca subcortical. La presentación clínica es variable, con cuadros que incluyen discapacidad intelectual, crisis epilépticas y trastornos de conducta muy variados, lo que hace complejo su diagnóstico. Presentamos el caso de un varón de 20 años con largo historial de epilepsia refractaria a tratamiento, remitido a nuestra unidad para un estudio de tomografía por emisión de positrones/tomografía computada (PET/CT) con 18F-fluorodesoxiglucos (18F-FDG) para la búsqueda del foco epileptógeno. Adicionalmente, se realizó un corregistro de PET con un estudio de resonancia magnética (RM) de otra institución, observando el signo de doble corteza cerebral por RM y PET/CT, visualizando característicamente un patrón hipermetabólico en las zonas de heterotopia subcortical en banda.
Abstract Subcortical band heterotopia (HSB) refers to the presence of smooth bilateral bands of gray matter located in the subcortical white matter. Clinical presentation is widely variable, the presentation includes intellectual disability, epileptic seizures and varied conduct disorders, making a complex diagnosis. We present a case of a 20-year-old male with a long history of treatment-refractory epilepsy referred to our center for a 18F-FDG (18F-fluorodeoxyglucose) PET/CT (Positron Emission Tomography/Computed Tomography), to search for the epileptogenic focus. Additionally, a registration was carried out with another magnetic resonance imaging study (MRI), where the sign of double cerebral cortex was documented by MRI and PET/CT, visualized as a hypermetabolic pattern in subcortical band heterotopia.
RESUMO
BACKGROUND: PSMA (prostate-specific membrane antigen) protein is heavily expressed in the proliferating microvasculature of high-grade gliomas (HGG) and brain metastases (BM). This research aimed to assess [99mTc]Tc-iPSMA SPECT brain imaging as a potential specific diagnosis of HGG and BM by PSMA-targeting in their proliferating vasculature. METHODS: Forty-one patients, with suspected brain tumors, as detected by enhanced MRI scanning, were enrolled to undergo preoperative [99mTc]Tc-iPSMA SPECT brain imaging. Semiquantitative image analyses, to evaluate the maximum target-to-background ratio (TBRmax), were performed. All diagnoses were histopathologically confirmed. PSMA expression was evaluated by immunohistochemistry (IHC) in 11 brain tumor tissues. TBRmax values were correlated with IHC results and tumor WHO grade (HGG vs LGG). RESULTS: [99mTc]Tc-iPSMA images showed increased uptake in BM, HGG, and recurrent gliomas (TBRmax of 25.1 ± 7.1, 18.5 ± 9.0, 15.0 ± 9.9, respectively), and was negative in treatment-naive patients with LGG and reactive gliosis. PSMA was highly expressed in the vascular endothelium of grade IV gliomas and BM, while its expression was extremely low in LGG and completely absent in gliosis. By using 2.8 as a threshold value for TBRmax, the specificity, sensitivity, PPV, NPV and accuracy were 100%, 94%, 100%, 77% and 95%, respectively. CONCLUSIONS: The results of this pilot study show that [99mTc]Tc-iPSMA SPECT brain imaging is a specific and potentially useful neuroimaging tool for assessing tumoral neovasculature formation in gliomas and brain metastases.
Assuntos
Antígenos de Superfície , Glioma , Glutamato Carboxipeptidase II , Neoplasias Encefálicas , Humanos , Pessoa de Meia-Idade , Projetos PilotoRESUMO
BACKGROUND: Gastric emptying scintigraphy has become the gold standard, by excellence, in gastric emptying studies. This method must be standardized for the correct interpretation of results. The ideal protocol must be performed with an egg sandwich or egg white poder, both labeled with 99mTc sulphur colloid. The aim of this study was to standardize and determine the protocol with99m Tc sulphur colloid incorporated in egg white and compare it with a hamburger labeled with 99mTc sulphur colloid as well. METHODS: We studied 30 patients who underwent gastric emptying scintigraphy with the two aforementioned meals. RESULTS: Emptying percentages and retention with both meals were similar within an hour and two; however, statistical significance arose until the third hour with a p value of 0.26 by using Student's t for independent samples. CONCLUSIONS: Gastric emptying studies in both protocols where similar with normal ranges. The egg white ingested must be consistent for reproducible results in gastric motility disease, like organoleptic and volume characteristics.
Introducción: la gammagrafía de vaciamiento gástrico (VG) es el estándar de oro para determinar el porcentaje de VG. La estandarización del método permite la obtención de resultados reproducibles. La dieta estandarizada se compone de un sándwich de albúmina de huevo en polvo reconstituida y marcada con 99mTc sulfuro coloidal (SC). El objetivo fue estandarizar y determinar el porcentaje de vaciamiento gástrico tras la ingesta del sándwich de albúmina de huevo y compararlo con el porcentaje de ingesta de una hamburguesa, ambos marcados con 99mTc sulfuro coloidal. Método: se incluyeron 30 pacientes a los que se les realizó estudio de gammagrafía de vaciamiento gástrico con las dos dietas propuestas. Resultados: los porcentajes de vaciamiento y retención con ambos tipos de alimentos fueron similares a la hora y a las dos horas; sin embargo, hubo diferencias significativas a las tres horas con un valor de p = 0.26, calculado mediante t de Student para muestras independientes. Conclusiones: los tiempos de vaciamiento gástrico con ambas dietas estuvieron dentro de rangos normales. La dieta estandarizada con albúmina de huevo reconstituida aporta ventajas en cuanto al estudio de las posibles alteraciones de la motilidad gástrica, como sus características organolépticas y de volumen.