Combined transbronchial needle aspiration and PET/CT for mediastinal staging of lung cancer

In this study, we aimed to evaluate the performance of transbronchial needle aspiration (TBNA) combined with positron emission tomography/computed tomography (PET/CT) for the staging of lung cancer. Twenty-five patients having lymphadenopathies greater than 1 cm on thorax CT and maximum standardized uptake value (SUVmax) ≥ 2.5 on PET/CT were included in this prospective study performed between March 2006 and March 2008. Forty-three lymphnode stations were sampled by using TBNA. Surgical histology, as confirmed by mediastinoscopy, was accepted as the "gold standard". The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of combined TBNA and PET/CT for correct lymph node staging were 67%, 100%, 100%, 76% and 84%; respectively. The initial clinical staging was downstaged after TBNA in 13/19 (69%) patients with adequate TBNA samples, whereas staging was correct in 17/19 (89%) patients assessed by combined TBNA and PET/CT. Staging was completed by TBNA, without mediastinoscopy, in 6/25 (24%) patients. Among the clinical factors that were assessed, only the PET SUVmax was associated with positive TBNA results [odds ratio (OR) 1.27, 95% CI 1.004-1.61, p= 0.046]. A PET SUVmax ≥ 5 was eleven times more likely in patients with positive TBNA results [OR 10.68, 95% CI 1.91-59.62, p< 0.01]. In conclusion, the combination of TBNA with PET/CT increased the sensitivity of TBNA. Combined TBNA and PET/CT may also allow adequate mediastinal staging of lung cancer in most patients with enlarged lymph nodes, and reduce the need for mediastinoscopy. The SUVmax cut off point for a positive TBNA result was ≥ 5.