RESUMEN
BACKGROUND: The CyberKnife is a new, frameless stereotactic radiosurgery system. This work reviews its safety and efficacy in the treatment of intra- and extracranial lesions. METHODS: A literature search was made of the Medline, Embase, Pascal Biomed, CINAHL and Cancerlit databases. Health technology assessment reports on stereotactic radiosurgery systems were also consulted. All searches were made in June 2007. Data on efficacy and safety were extracted and then synthesized into the present review. RESULTS: Thirty five clinical studies were identified, the majority of which included no patient comparison group. These studies assessed the use of the CyberKnife mainly in the treatment of primary and metastatic intracranial and spinal tumours. CONCLUSIONS: The CyberKnife system allows to carry out standard radiosurgical and fractionated stereotactic radiotherapy procedures. The use of this system offers an alternative for the treatment of inoperable tumours, and of lesions located close to critical structures that cannot be treated using other types of stereotactic radiosurgery system. Unfortunately, the quality of the reviewed papers still does not allow definite conclusions to be drawn regarding the safety and efficacy of these treatments.
Asunto(s)
Neoplasias Encefálicas/cirugía , Radiocirugia/métodos , Robótica , Neoplasias de la Columna Vertebral/cirugía , Cirugía Asistida por Computador/métodos , HumanosRESUMEN
The objective of etiologic research is to look for the causes of disease, their relationships with it, and their relative magnitude on the appearance of the disease. The observational studies (in which there is no manipulation of the study factor), that are performed when the knowledge about the disease to be studied allows to specify beforehand one or more hypothesis that can be tested are called etiologic or analytic studies. The objective of etiologic studies is to identify risk factors for a given disease, to estimate their effects on the appearance of disease, and also to suggest a possible strategy of interventions to diminish the appearance of disease. Case-control and cohort studies are the etiologic studies more often used, characteristics of which will be exposed in this article.
Asunto(s)
Investigación Biomédica/métodos , Proyectos de Investigación , Enfermedades Urológicas/etiología , Urología/métodos , Estudios de Casos y Controles , Estudios de Cohortes , Humanos , Factores DesencadenantesRESUMEN
La investigación etiológica tiene por objetivo buscar las causas de la enfermedad, sus relaciones con ella, y su magnitud relativa en la aparición de la enfermedad. Los estudios observacionales (en los que no existe manipulación del factor de estudio) que se realizan cuando los conocimientos de la enfermedad a estudio permiten especificar a priori una o más hipótesis que pueden ser testadas, son los denominados estudios etiológicos o analíticos. El objetivo de los estudios etiológicos es identificar factores de riesgo de una enfermedad, estimar sus efectos en la aparición de la enfermedad y asimismo, sugerir una posible estrategia de intervención para disminuir la aparición de la enfermedad.Los estudios etiológicos utilizados con más frecuencia son los estudios caso-control y los estudios de cohortes, de los que se expondrán sus características más importantes en este artículo. (AU)