Computed tomography for preoperative evaluations of lung cancer

Computed tomography was evaluated for its accuracy in diagnosing mediastinal node metastases, direct chest wall invasion, and direct mediastinal invasion by lung cancer among 61 patients who subsequently underwent surgery. Using 15-mm diameter or larger mediastinal lymph nodes as the criterion for metastasis, the sensitivity was 36% (8/22); the specificity was 92% (34/37). The accuracy for direct chest wall invasion was relatively high, with a sensitivity of 100% (7/7) and a specificity of 92% (22/24). Direct mediastinal invasion had a sensitivity of 67% (4/6) and a specificity of 91% (10/11). These results suggest that the ability of computed tomography to diagnose mediastinal lymph node metastasis when such nodal size is used as a criterion is limited.