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In this study, we report the electrocatalytic oxidation of glycerol in alkaline solution onto Ni modified pencil graphite electrodes (Ni/PGEs). Field-emission gun scanning electron microscopy (FEG-SEM) and energy-dispersive X-ray spectroscopy (EDX), as well as cyclic voltammetry (CV) have been used for the clarification of the physicochemical and electrochemical properties of Ni/PGEs. The electrocatalytic performance of Ni/PGEs towards glycerol electrooxidation was investigated using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Ni/PGE elaborated at pH = 6.92 showed the best performance for glycerol electrooxidation reaction in alkaline media. The direct comparison of glycerol, methanol, and ethanol electrooxidation revealed that glycerol is better than ethanol at 35 and 45 °C with a lower onset potentials and higher current densities. Ni/PGE characteristics surpass other nickel based electrodes and therefore promote its use as glycerol electrocatalyst.

Resumen Objetivo El objetivo de nuestro estudio fue analizar la posible relacion entre los marcadores tumorales y los resultados de la tomografia por emision de positrones con 18F-fluorodoxiglucosa/tomografia computarizada (18F-FDG PET/TC) en pacientes afectados por seminoma. Material y metodo Se analizaron 65 exploraciones PET/TC 18F-FDG de 41 pacientes con diagnostico de seminoma y se compararon con alfafetoproteina (AFP) y gonadotropina corionica humana (hCG). Los estudios PET/TC se analizaron cualitativamente y midieron el valor maximo y medio de la captacion estandarizada de peso corporal maximo (SUVbwmax, SUVbwmean), masa corporal magra SUVmax (SUVlbm), area de superficie corporal maxima de SUV (SUVbsa), volumen tumoral metabolico (MTV) y glucolisis de lesion total (TLG) de lesiones hipermetabolicas. Todos los valores se compararon con los marcadores sericos. Resultados 31 estudios PET/TC fueron verdaderos negativos, 28 verdaderos positivos, seis falsos positivos y cero falsos negativos con sensibilidad del 100%, especificidad del 84%, valor predictivo negativo del 100%, valor predictivo positivo del 82% y precision de 91%. No se encontro correlacion entre los resultados de PET y los niveles de marcadores tumorales y tampoco entre los parametros semicuantitativos de la PET/TC y la AFP. Todos los parametros semicuantitativos de PET se relacionaron significativamente con el nivel de hCG. Conclusiones 18F-FDG PET/TC tiene buena precision en la evaluacion de pacientes con seminoma recidivante. Los niveles de hCG se correlacionaron significativamente con los parametros metabolicos de PET/TC.

Objective The aim of our study was to analyze the potential relationship between tumor markers and 18F-fluorodoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) results in patients affected by seminoma. Material and methods 65 18F-FDG PET/CT scans of 41 patients with diagnosis of seminoma were analyzed and compared to alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). PET/CT studies were analyzed qualitatively and measuring the maximum and mean standardized uptake value body weight max (SUVbwmax, SUVbwmean), maximum SUV lean body mass (SUVlbm), maximum SUV body surface area (SUVbsa), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of hypermetabolic lesions. All values were compared with serum markers. Results 31 PET/CT studies were true negative, 28 true positive, 6 false positive and 0 false negative with sensitivity of 100%, specificity of 84%, negative predictive value of 100%, positive predictive value of 82% and accuracy of 91%. No correlation between PET results and tumor marker levels was found and also between AFP and PET/CT semiquantitive parameters. All semiquantitative PET parameters were significantly related to hCG level. Conclusions 18F-FDG PET/CT has good accuracy in evaluating patients with relapsed seminoma. HCG levels were significantly correlated with metabolic PET/CT parameters.

Resumen Objetivo El objetivo de este estudio fue investigar la precision diagnostica de la PET/TC con 18F-FDG en la estadificacion del cancer de laringe, comparar estos resultados con las tecnicas de imagen convencional ( C I) y evaluar los parametros metabolicos para predecir la supervivencia. Metodos Estudio retrospectivo que incluye cincuenta y cuatro pacientes con cancer escamoso de laringe que acudieron para realizacion de estadificacion mediante PET/TC con 18F-FDG. Las imagenes PET se analizaron visualmente y semicuantitativamente midiendo varios parametros metabolicos. Se tomo como estandar de referencia el seguimiento clinico, por imagen y/o histopatologia. Se calculo el tiempo libre de enfermedad y la supervivencia mediante curvas de Kaplan-Meier. Resultados Todos los tumores fueron identificados por las CI y 52/54 por la PET/TC con 18F-FDG, con sensibilidad del 96,3%. La sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo y precision, basada en el analisis por paciente para la deteccion de enfermedad ganglionar fue del: 100%, 85,7%, 94,6%, 100% y 95,9% para la PET/TC con 18F-FDG y del 91,4%, 85,7%, 94,1%, 80% y 89,9% para las CI. El rendimiento diagnostico de la PET/TC y las CI no fue significativamente diferente ni en analisis por paciente, ni en el de la lateralizacion ni el de los niveles ganglionares. La PET/TC con 18F-FDG detecto metastasis a distancia en 7 pacientes que permitieron una estadificacion superior. En una mediana de seguimiento de 27 meses, la recaida/progresion de la enfermedad ocurrio en 31 pacientes y muerte en 32. El volumen metabolico tumoral (VMT) y la glucolisis total (TLG) de la lesion primaria se mostraron como factores pronosticos independientes para el tiempo libre de enfermedad. Conclusiones Tanto las CI como la PET/TC con 18F-FDG mostraron resultados diagosticos en la estadificacion del cancer de laringe. Los parametros metabolicos basales (MTV y TLG) mostraron valor pronostico en la evaluacion del tiempo libre de enfermedad.

Introduction Splenic marginal zone lymphoma (SMZL) is an indolent non-Hodgkin lymphoma usually with a good prognosis, but no clear metabolic behavior at fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). The aim of our analysis was to investigate the prognostic role of baseline 18F-FDG PET/CT parameters in SMZL. Materials and Methods We retrospectively included 42 patients who received 18F-FDG-PET/CT before any treatments, and PET images were evaluated visually and semi-quantitatively by measuring lesion to liver (L-L) maximum standardized uptake volume (SUVmax) ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), metabolic tumor volume, and total lesion glycolysis. Progression-free (PFS) and overall survival (OS) curves were plotted according to the Kaplan-Meier method. Results In all patients, an increased splenic FDG uptake (higher than the background) was identified, showing the presence of diffuse spleen uptake in 35 patients and focal uptake in the remaining 7 patients. At a median follow-up of 51 months, relapse or progression of disease occurred in 23 patients with an average time of 38.1 months from the baseline 18F-FDG PET/CT, and death occurred in 4 patients with an average time of 26.8 months. The estimated 2-year PFS and OS rates were 78% and 90%, respectively, whereas 5-year PFS and OS rates were 63% and 82%, respectively. At multivariate analysis, only L-L SUV R and L-BP SUV R were independent prognostic factors for PFS. In addition, no significant association was discovered for OS, considering all features. Conclusions L-L SUV R and L-BP SUV R were independently correlated with PFS.

Resumen Antecedentes El comportamiento metabolico del plasmocitoma en la PET/TC con 18F-FDG no esta claro. Objetivo Realizar una revision sistematica sobre la utilidad diagnostica de la PET o PET/TC con 18F-FDG en pacientes afectos de plasmocitoma. Metodos Se ha realizado una busqueda exhaustiva bibliografica de articulos relevantes en las bases de datos de Scopus, PubMed/MEDLINE, Embase y Cochrane Library desde julio de 2019. Resultados La busqueda exhaustiva bibliografica ha revelado 371 articulos; al revisar los titulos y los resumenes, se excluyeron 363 articulos porque los datos que aportaban no estaban dentro del campo de interes de esta revision. En total, en esta revision sistematica se incluyeron 8 articulos. Los principales hallazgos del analisis de los articulos seleccionados han sido: 1) El plasmocitoma generalmente es un tumor avido de 18F-FDG y la PET/TC muestra un buen rendimiento diagnostico, con alta sensibilidad; 2) en la mayoria de los casos la PET/TC con 18F-FDG ha influido en el manejo de los pacientes, permitiendo seleccionar el tratamiento y evitando terapias ineficaces; 3) el valor pronostico de los parametros cualitativos y semicuantitativos de la PET/TC con 18F-FDG sigue mostrando un caracter controvertido con los resultados obtenidos. Conclusion A pesar de las limitaciones de estos hallazgos, dado el reducido numero de trabajos y pacientes estudiados, el plasmocitoma parece ser un tumor avido de 18F-FDG en la mayoria de los casos. La PET o PET/TC con 18F-FDG muestra un buen rendimiento diagnostico, con impacto clinico significativo en el cambio de enfoque terapeutico. Finalmente, parece existir un probable valor pronostico de la PET/TC con 18F-FDG.

Background The metabolic behavior of plasmacytoma at 18F-FDG PET/CT is not yet clear. Objective The aim of this systematic review was to analyze published data about the role of 18F-FDG PET or PET/CT in patients affected by plasmacytoma. Methods A comprehensive computer literature search of the Scopus, PubMed/MEDLINE, Embase and Cochrane library databases was conducted including articles up to July 2019 to find relevant published papers about the performance of 18F-FDG PET and PET/CT in plasmacytoma. Results The comprehensive computer literature search revealed 371 articles. On reviewing the titles and abstracts, 363 articles were excluded because the reported data were not within the field of interest of this review. Eight articles were selected and retrieved in full-text version. From the analyses of the selected studies, the following main findings have been founded: 1) plasmacytoma generally is a 18F-FDG-avid tumor and PET/CT had good diagnostic performance with high sensitivity; 2) 18F-FDG PET/CT influenced patient management in most cases avoiding useless therapies and choosing the best therapeutic approach; 3) prognostic value of PET/CT qualitative and semiquantitative parameters is only suggested with controversial reports. Conclusion Despite several limitations affect this analysis, especially related to the low number of articles and patients studied, plasmacytoma looks to be an 18F-FDG-avid tumor in most of the cases; 18F-FDG PET or PET/CT had good diagnostic performance and had a significant clinical impact in change of therapeutic approach. Moreover, a possible prognostic role of PET/CT features is described.