308 research outputs found
Volumetric burden of metastatic lesions drives outcomes in patients with extracranial oligometastatic disease
Stereotactic radiotherapy for early stage non-small cell lung cancer
Stereotactic body radiotherapy (SBRT) represents a consolidated treatment option for patients with medically inoperable early stage non-small cell lung cancer (NSCLC). The clinical evidence accumulated in the past decade supports its use as an alternative to surgery with comparable survival outcomes. Due to its limited toxicity, SBRT is also applicable to elderly patients with very poor baseline pulmonary function or other severe comorbidities. Recent comparative studies in operable patients raised the issue of the possible use of SBRT also for this subgroup, with quite promising results that still should be fully confirmed by prospective trials with long-term follow-up. Aim of this review is to summarize and discuss the major studies conducted over the years on SBRT and to provide data on the efficacy and toxicity of this radiotherapy technique for stage I NSCLC. Technical aspects and quality of life related issues are also discussed, with the goal to provide information on the current role and limitations of SBRT in clinical practice
Clinical applications of stereotactic radiation therapy for oligometastatic cancer patients: a disease-oriented approach
Oligometastases from solid tumors are currently recognized as a distinct clinical entity, corresponding to an intermediate state between local and widespread disease. It has been suggested that local ablative therapies (including surgery, radiofrequency ablation and radiation therapy) play an important role in this setting, in combination or not with systemic therapies, particularly in delaying disease progression and hopefully in increasing the median survival time. Stereotactic body radiation therapy (SBRT) rapidly emerged in recent years as one of the most effective and less toxic local treatment modalities for lung, liver, adrenal, brain and bone metastases. The aim of this review was to focus on its clinical role for oligometastatic disease in four major cancer subtypes: lung, breast, colorectal and prostate. On the basis of the available evidence, SBRT is able to provide high rates of local tumor control without significant toxicity. Its global impact on survival is uncertain; however, in specific subpopulations of oligometastatic patients there is a trend towards a significant improvement in progression-free and overall survival rates; these important data might be used as a platform for clinical decision-making and establish the basis for the current and future prospective trials investigating its role with or without systemic treatments
Electrochemical control of aqueous solution pesticide: study for the degradation of 2,4-dichlorophenoxyacetic acid
Orientador: Rodnei BertazzoliDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecanicaResumo: Nest trabalho foi investigada a desempenho do peróxido de hidrogênio eletrogerado a partir de redução do oxigênio na superfície de um catodo de carbono vítreo reticulado para a oxidação do herbicida ácido 2,4-diclorofenoxiacético. Inicialmente, foram feitas voltametrias cíclicas para verificar se o 2,4-D para verificar a existência de pares redox. O eletrólito suporte usado foi o K2SO4 0,3 mol L-1, pH 10, em meio saturado de N2. Após a verificação da ausência de reação redox para o 2,4-D, fez-se a otimização da eletrogeração de peróxido de hidrogênio. Usando como catodo um eletrodo rotatório cilíndrico de carbono vítreo reticulado de 60 ppi e um anodo de platina, em meio de K2SO4 0,3 mol L-1, pH 10, saturado com O2 e 900 rpm, determinou-se que o melhor potencial para eletrogeração de H2O2 foi de ¿ 1,6 V vs. ECS a uma temperatura de 8 0C. Em etapa subseqüente, verificou-se a degradação do herbicida 2,4-D em solução, na concentração de 100 mg L-1 por diferentes três processos: H2O2 eletrogerado, UV/H2O2, e fotoeletro-Fenton, este último realizado em pH 2,5. Para tanto foram feitas injeções no Cromatógrafo Líquido de Alta Eficiência, além de análise de Carbono Orgânico Total e Demanda Química de Oxigênio. Dos processos estudados, o mais vantajoso foi o catalisado com radiação UV e sais de Fe2+ (Reagente de Fenton), com uma redução do COT de 69 % do valor inicial. Dando continuidade os estudos, foi construído um reator em escala piloto do tipo filtro prensa com fluxo transversal para eletrogeração de peróxido de hidrogênio. Composto por dois compartimentos anódicos e um catódico, separado por membranas catiônicas Nafion ®N242, o reator foi otimizado em três diferentes parâmetros: o potencial de trabalho, a velocidade de vazão do fluido e a vazão de oxigênio. Os valores ótimos encontrados para eletrogeração de H2O2 em eletrólito suporte de K2SO4 0,3 mol L-1 foram: potencial de -1,6 V vs. Pt, velocidade do fluido de 500 L h-1 e vazão de oxigênio de 6 L s-1. Com o reator otimizado e acumulando cerca de 1100 mg L-1 de H2O2 em 5 horas de processo, foram feitos ensaios de degradação do 2,4-D em seis deferentes métodos: dois ensaios em meio básico com e sem incidência de radiação ultravioleta, e em seguida, mais quatro ensaios em meio ácido, também com e sem a incidência de radiação ultravioleta, na presença do reagente de Fenton, e por fim, um ensaio catalisado com radiação ultravioleta e na presença do reagente de Fenton. Os ensaios em meio ácido e catalisado, mais uma vez se mostraram mais eficientes e a remoção do COT seguiu uma cinética de pseudo-primeira ordem. Mesmo não havendo muita variação no tempo de degradação o gráfico de ln[C(t)/C(0)] vs. tempo, mostra que o processo mais vantajoso é aquele catalisado com UV/Fenton, com uma constante de redução do COT uma ordem de grandeza maior do que para o processo apenas com incidência de radiação UV. Os valores foram, respectivamente, 9,4x10-5 s-1 e 1,75x10-4 sAbstract: In this work, the performance of the H2O2 electrogeneration process from O2 reduction on a reticulated vitreous carbon cathode was investigated. The process was also use for the oxidation of the herbicide 2,4-dichlorophenoxyacetic acid. Firstly, cyclic voltammetries were used for the identification of possible reduction reactions of the herbicide. The supporting electrolyte used was a 0,3 mol L-1 K2SO4, pH 10, nitrogen saturated solution. Then, the optimization of hydrogen peroxide electrogeneration it was carried out. As a cathode, a reticulated vitreous carbon-rotating cylinder, shaped from a 60 ppi RCV plate was used. A platinum foil was used as anode and a saturated calomel electrode was used as reference. Supporting electrolyte was always K2SO4 0,3 mol L-1, in an O2 saturated solution. The experiments were run in a 150 mL electrode cell, with a water jacket to keeping temperature in the range from 8 0C. The best potential to produce hydrogen peroxide in these conditions was -1,6 V vs. SCE. In following stage, the degradation of 2,4-D was investigated by tree different process: H2O2 electrogenerated, H2O2/UV and photo electro-Fenton being the last at pH 2,5. The degradation of 2,4-D was followed by HPLC, moreover TOC and COD analyses. The most efficient process was the catalyzed UV/Fe2+ process that presented a TOC reduction of 69 %. In a sequence, a pilot scale reactor was mounted for hydrogen peroxide electrogeneration. The reactor is formed by two anolytes and one catholyte compartments, separated by a N424 Nafion® membrane. The reactor was optimized considering three different parameters: the applied potential, oxygen flow and the electrolyte flow. Best operational parameters electrogeneration rate of hydrogen peroxide in a K2SO4 0,3 mol L-1 electrolyte support were: -1,6 V vs. Pt, 500 L h-1 of electrolyte flow and 6 L s-1 of oxygen flow. Considering these results, the experiments for the degradation of 2,4-D were conducted with the optimized reactor. In this new series of experiments, six different processes were tested. In alkaline medium, the degradation occurred only with H2O2 and H2O2, catalyzed by UV radiation. Four processes were used in acidic medium: H2O2, H2O2 catalyzed by UV radiation, Fe2+ (electro Fenton process) and H2O2 with Fe2+ catalyzed by UV radiation (photo-electro Fenton process). In catalyzed experiments in acidic medium, degradation rates were higher TOC decay presented a pseudo-first order kinetic. The differences between electro Fenton and photo-electro Fenton processes appeared only when TOC reduction was considered. A greater degree of organics combustion was observed for the last process, with 95 % of TOC was eliminated.MestradoEngenharia de MateriaisMestre em Engenharia Mecânic
Prevalencia de asma, rinoconjuntivitis alérgica y eccema en niños y adolescentes: comparación de la población urbana de San Francisco, Córdoba, y la zona rural circundante
Las enfermedades alérgicas constituyen un problema de notable impacto en la salud pública por su alta prevalencia y por afectar la calidad de vida de quienes las padecen. La prevalencia de las mismas ha ido en aumento en muchos países en los últimos años. Con el objetivo de conocer su prevalencia en el medio urbano de San Francisco, Córdoba, Argentina, y en la zona rural circundante y de identificar los factores medioambientales que pueden ejercer un efecto protector y de riesgo en dicha prevalencia se encaró el presente estudio, siguiendo las directivas del estudio ISAAC. Se identificaron algunos factores de riesgo para sama como el sobrepeso y la obesidad, el uso de paracetamol, el cigarrillo y en los Urbanos el contacto con animales de granja y cereales. Fueron factores de protección el consumo de algunos alimentos, la leche no pasteurizada, y el contacto con animales de granja y cereales en los Rurales.Fil: Badellino, Héctor Ariel. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; Argentin
Prevalencia de asma, rinoconjuntivitis alérgica y eccema en niños y adolescentes: comparación de la población urbana de San Francisco, Córdoba, y la zona rural circundante
Las enfermedades alérgicas constituyen un problema de notable impacto en la salud pública por su alta prevalencia y por afectar la calidad de vida de quienes las padecen. La prevalencia de las mismas ha ido en aumento en muchos países en los últimos años. Con el objetivo de conocer su prevalencia en el medio urbano de San Francisco, Córdoba, Argentina, y en la zona rural circundante y de identificar los factores medioambientales que pueden ejercer un efecto protector y de riesgo en dicha prevalencia se encaró el presente estudio, siguiendo las directivas del estudio ISAAC. Se identificaron algunos factores de riesgo para sama como el sobrepeso y la obesidad, el uso de paracetamol, el cigarrillo y en los Urbanos el contacto con animales de granja y cereales. Fueron factores de protección el consumo de algunos alimentos, la leche no pasteurizada, y el contacto con animales de granja y cereales en los Rurales.Fil: Badellino, Héctor Ariel. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; Argentin
Locally-advanced non-small cell lung cancer: Shall immunotherapy be a new chance?
Locally advanced non-small cell lung cancer (NSCLC) represents approximately one third of presentations at diagnosis. Most patients are judged non-surgical due to disease extension, and chemo-radiotherapy still represents the standard therapeutic option, with unsatisfactory results in terms of overall survival (OS) despite advances in staging and radiation therapy planning and delivery. Immunotherapy, and in particular immune-checkpoint inhibitors targeting the PD-1/PD-L1 axis, gained wide popularity for NSCLC in light of the positive findings of several trials in metastatic disease. Stage III unresectable NSCLC is a remarkably interesting setting for the combined use of chemo-radiation and immunotherapy, also considering the multiple experimental evidences in favor of a synergistic effect between radiation and immune checkpoint inhibitors, with the potential of enhancing immuno-modulating effects and overcoming resistance. We here summarized the biological rationale and the initial clinical experiences testing for this combination, and we briefly discussed ongoing trials and future options in this field
Modern Radiation Therapy for the Management of Brain Metastases From Non-Small Cell Lung Cancer: Current Approaches and Future Directions
Brain metastases (BMs) represent the most frequent event during the course of Non-Small Cell Lung Cancer (NSCLC) disease. Recent advancements in the diagnostic and therapeutic procedures result in increased incidence and earlier diagnosis of BMs, with an emerging need to optimize the prognosis of these patients through the adoption of tailored treatment solutions. Nowadays a personalized and multidisciplinary approach should rely on several clinical and molecular factors like patient’s performance status, extent and location of brain involvement, extracranial disease control and the presence of any “druggable” molecular target. Radiation therapy (RT), in all its focal (radiosurgery and fractionated stereotactic radiotherapy) or extended (whole brain radiotherapy) declinations, is a cornerstone of BMs management, either alone or combined with surgery and systemic therapies. Our review aims to provide an overview of the many modern RT solutions available for the treatment of BMs from NSCLC in the different clinical scenarios (single lesion, oligo and poly-metastasis, leptomeningeal carcinomatosis). This includes a detailed review of the current standard of care in each setting, with a presentation of the literature data and of the possible technical solutions to offer a “state-of-art” treatment to these patients. In addition to the validated treatment options, we will also discuss the future perspectives on emerging RT technical strategies (e.g., hippocampal avoidance whole brain RT, simultaneous integrated boost, radiosurgery for multiple lesions), and present the innovative and promising findings regarding the combination of novel targeted agents such as tyrosine kinase inhibitors and immune checkpoint inhibitors with brain irradiation
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