ABSTRACT
Os corretos diagnósticos e estadiamento do câncer de pulmão são verdadeiros desafios na prática clínica diária do pneumologista e do cirurgião de tórax. O surgimento de técnicas endoscópicas minimamente invasivas como o ultrassom endobrônquico (EBUS) e a técnica de aspiração transbrônquica por agulha fina guiada por ultrassom endobrônquico (EBUS-TBNA) vem mudando significativamente a abordagem da neoplasia pulmonar. Desde sua descrição na literatura médica há cerca de uma década, inúmeros trabalhos, incluindo ensaios clínicos controlados, revisões sistemáticas e metanálises têm demonstrado a importância do método. A propagação da técnica de EBUS-TBNA pelo mundo e sua incorporação por serviços de referência em pneumologia no Rio de Janeiro e no Brasil torna importante uma revisão atual das características técnicas do procedimento e dados relevantes da literatura sobre o tema.
The correct diagnosis and staging of lung cancer are real challenges in the daily clinical practice of the pulmonologist and the chest surgeon. The emergence of minimally invasive endoscopic techniques such as endobronchial ultrasound (EBUS) and the endobronchial ultrasound-guided transbronchial needle aspiration technique (EBUS-TBNA) have significantly changed the approach of pulmonary neoplasia. Since its description in the medical literature about a decade ago, countless studies, including controlled clinical trials, systematic reviews and meta-analyzes have demonstrated the importance of the method. The spread of the EBUS-TBNA technique throughout the world and its incorporation by pneumology referral services in Rio de Janeiro and Brazil makes it important to have a current review of the technical characteristics of the procedure and relevant literature data on the subject.
Subject(s)
Humans , Male , Female , Endoscopic Ultrasound-Guided Fine Needle Aspiration , Lung Neoplasms/diagnosis , Neoplasm Staging , UltrasonographyABSTRACT
La estadificación mediastinal en cáncer de pulmón en pacientes potencialmenteoperables constituye un paso crítico para determinar la estrategia terapéutica. De los métodos de estadificación la mediastinoscopia es el gold estándar con una sensibilidadde 80% y baja morbilidad. Sin embargo, no deja de ser un procedimiento quirúrgico. Métodos endoscópicos utilizando ultrasonografía como guía para la punción con aguja fina han emergido como métodos mínimamente invasivos ofreciéndose como alternativaa los métodos quirúrgicos. Con reconocida precisión diagnóstica y sensibilidad, estos métodos van ocupando un lugar en la estadificación mediastinal. Esta revisión abordaprincipios, aplicaciones clínicas y el papel de esta nueva tecnología en la estadificación del cáncer de pulmón.
Mediastinal staging of lung cancer in potentially operable patients is a critical step in determining the therapeutic strategy. Among the methods of staging, mediastinoscopy is the gold standard because it combines an 80% sensitivity with a low rate of complications.However it remains a surgical procedure. Methods using endoscopic ultrasound to guide fine needle aspiration emerged as minimally invasive procedures presenting an alternative to surgical methods. Because of their established diagnostic accuracyand sensitivity these methods are occupying a place in the mediastinal staging. This review deals with principles, clinical applications and the role of this new technologyin the staging of lun cancer.
Subject(s)
Humans , Lung Neoplasms , Mediastinum , Neoplasm Staging , Bronchoscopy , UltrasonographyABSTRACT
PURPOSE: Mediastinal staging of non-small cell lung cancer can be markedly improved by FDG-PET scan, but the problem of false staging of mediastinal nodes by PET scan in non-small cell lung cancer has not yet been overcome. The aim of this study was to identify the mechanism underlying the false staging of mediastinal nodes by FDG-PET in the case of non-small cell lung cancer. MATERIALS AND METHODS: To evaluate the factors determining the FDG uptake in mediastinal nodes, FDG-PET was performed preoperatively, and mediastinal dissection with pulmonary resection was performed in 62 patients with NSCLC. GLUT-1 expression was studied by immunohistochemistry of the mediastinal nodes (n=111, true positive 31, true negative 41, false positive 27, false negative 12) using the anti-GLUT-1 antibody. The size, percentage of tumor (tumor ratio), labeling index (rate of stained tumor), staining intensity of the tumor, level of follicular hyperplasia, and staining intensity of the follicle center in the mediastinal node were also studied. RESULTS: There was no significant difference in size among the 4 nodal groups (TP, TN, FP, FN), nor in the tumor ratio of the metastatic nodes between the TP and FN groups. The labeling index and staining intensity of the TP group were higher than those of the FN group (Mann-Whitney test, p=.001, p=.007) in the case of the metastatic nodes. The level of follicular hyperplasia of the FP group was higher than that of the TN group in the case of the non-metastatic nodes (p=.000). CONCLUSION: These results suggest that in mediastinal staging of non-small cell lung cancer by FDG-PET, the FN node is associated with low uptake of FDG due to low expression of GLUT-1, and that the FP node is associated with a high level of follicular hyperplasia as a result of there being a reactive change to an inflammatory and/or immune reaction. This is the first report on the mechanism underlying the false results that are sometimes obtained, and which constitute a major problem in the clinical application of FDG-PET to the mediastinal staging of non-small cell lung cancer.