The role of positron emission tomography in mediastinal staging of patients with non-small cell lung cancer.

OBJECTIVE To examine the diagnostic accuracy of positron emission tomography/computed tomography in evaluating the mediastinum of patients with non-small cell lung cancer compared to histopathology results. METHODS The prospective study was conducted at the Department of Thoracic Surgery of the Pulmonary Hospital in Zakopane, Poland, from September 2008 to August 2012 and comprised patients with radiologically-suspected lung cancer. All patients underwent histological verification by either mediastinoscopy alone or thoracotomy with mediastinal lymphanedectomy. Computed tomography and positron emission tomography/computed tomography data sets were compared with the results of the histopathology examinations. RESULTS There were 80 patients in the study. In the diagnosis of mediastinal lymph nodes, computed tomography was able to detect 9(11.25%) true-positive, 17(21.25%) false-positive, 40(50%) true-negative and 14(17.5%) false-negative cases. The sensitivity, specificity and accuracy of the method were found to be 39%, 70% and 61% respectively, while the positive and negative predictive values were 35% and 74%. Positron emission tomography/computed tomography yielded 15(18.75%) true-positive, 12(15%) false-positive, 46(57.5%) true-negative and 7(8.75%) false-negative cases. Sensitivity was 68% while specificity was 79%. The accuracy was 96%, and the positive and negative predictive values were 55% and 87% respectively. CONCLUSION Positron emission tomography/computed tomography had higher diagnostic accuracy than computed tomography in assessing mediastinal lymph nodes of patients with non-small cell lung cancer. However, a positive test requires histopathology confirmation.