Thoracic CT scanning in the staging of bronchogenic carcinoma

The use of thoracic CT scans in the staging of bronchogenic carcinoma has been controversial. Previous studies have resulted in conflicting conclusions concerning the incidence of false positive and false negative scans. We attempted to determine if thoracic CT scans were of value in staging bronchogenic carcinoma using objective criteria and in a clinical situation applicable to most modern medical centers. Forty-eight patients who had a staging mediastinoscopy and/or thoracotomy and a CT scan prior to surgery were studied. Twenty-eight had evidence of mediastinal node enlargement on CT scan, and 19 of those patients had metastatic disease confirmed. One of 20 patients without evidence of mediastinal lymph node enlargement on CT scan had lymph node metastases at surgery. The CT scan was 68.0 percent specific, 95.0 percent sensitive, and 79.2 percent accurate in predicting mediastinal neoplastic involvement. No difference was noted between left upper lobe tumors and tumors arising in other areas of the lung. We conclude that the third generation chest CT scan is extremely sensitive in identifying enlarged mediastinal lymph nodes, but this is not specific for metastatic disease. Patients with a positive chest CT scan should have pathologic confirmation of metastatic disease with a surgical staging procedure. Patients with a negative chest CT scan, however, can be taken directly to thoracotomy.