Accuracy of computed tomography of the mediastinum in bronchogenic carcinoma

The results of preoperative CT-scanning were compared with the pathological findings in lymph-nodes taken at mediastinoscopy and/or thoracotomy in 144 patients to determine the accuracy of CT of the mediastinum in staging lung cancer. Ninety-nine patients had squamous cell carcinoma, 31 adenocarcinoma, nine undifferentiated large-cell carcinoma and five patients had carcinoma of a mixed cellular type. Mediastinoscopy was done in 105 patients and thoracotomy in 126. The results of our study showed that CT is useful to select patients for mediastinoscopy for T1 lung cancer in general because of a negative predictive value of 98 per cent. CT is also useful for T2 and T3 lung cancer located at the left lower lobe or the right upper, middle or lower lobe (negative predictive value 87%). However, mediastinoscopy is always necessary in patients with T2 or T3 lung cancer at a main bronchus or a left upper lobe because of the low negative predictive value (58%). Preoperative aorto-pulmonary window evaluation is not recommended in case the CT-scan for the aortopulmonary window is negative because of a reasonable negative predictive value (81%).