The Diagnostic Accuracy of Computed Tomography Compared with Ga-67 Scintigraphy and Bronchial Arteriography in the Evaluation of Mediastinal Lymph Node Involvement in Lung Cancer

The diagnostic accuracy of computed tomography (CT) was compared with Ga-67 scintigraphy and bronchial arteriography in the evaluation of mediastinal lymph node involvement in patients with surgically and histologically proven lung cancer. CT scan of the mediastinum had 89.5% sensitivity (true-positive rate) with only 2 false negative scan cases (10.5%), which was more sensitive than the sensitivity of 36.1% of Ga-67 scintigraphy and 56% of bronchial arteriography. However, the specificity (true-negative rate) of the CT examination was not so high (58.8%) with 14 false positive cases (41.2%), compared with a specificity of 79.6% and 71.6% for the other two methods. As a result of this study, CT was sufficiently sensitive as a noninvasive method to evaluate the mediastinum presurgically. Ga-67 scintigraphy was also effective in patients with gross nodal involvement in the mediastinum, because it was less sensitive, but more specific than CT. However, bronchial arteriography demonstrated better results in sensitivity and almost the same specificity as Ga-67 scintigraphy, but as it is an invasive procedure, indications were limited.