Mediastinal lymph node staging in patients with non-small cell lung cancer (NSCLC) with F18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT).

Abstract

e17503 Background: Lung cancer is the leading cause of cancer-related deaths in the Western world. CT and mediastinoscopy are the standard for staging modalities in recent years; PET has emerged as a complement to other techniques. Mediastinal lymph node (MLN) staging is important because it establishes subsequent treatment. The aim of the present study is to analyze the relationship between mediastinal staging by endobronchial ultrasound-guided transbronchial needle aspiration, mediastinoscopy, lymphadenectomy and PET. It also analyzes the patient characteristics like age, sex, histology. Methods: The study prospectively evaluated 42 patients from August 2009 to March 2011. All of them had MLN staging by PET and pathology (tumor resection with systematic lymph node dissection, transbronchial needle aspiration or mediastinoscopy). Univariable date analysis was conducted using Pearson's chi-square test. P values were considered statistically significant if <0.05. Results: The study group comprised 42 patients, 83% men and 17% female, mean age of 66 years. The primary tumor cell type: 45% squamous cell, 33% adenocarcinoma and 19% large cells. 40 patients were smoking. The most frequent location of tumor was upper lobes (58%). The most common stage found after surgery was stage I (42%), stage II (19%), stage III (A: 29%, B: 5%) and stage IV (5%). The kappa statistic for diagnostic agreement between CT and PET was 0.53 (p<0.001). About MLN staging, PET has a sensitivity of 61% and specificity of 53% , positive predictive value 61% and negative 53%. Conclusions: The present study attempts to find the relationship between tumor involvement found in PET and resected tumor specimens obtained from the mediastinum. Our sensitivity and specificity were not concordant with those previously reported; this may be due to the learning curve at our center or the shortness of our series. In contrast we conducted histological examination of all involved MLNs, supporting our data and shows that this confirmation can lead to a change of therapeutic strategy in some cases.