Detecting mediastinal lymph node metastases in non-small-cell lung cancer using a combination of technetium-99m tetrofosmin chest single photon emission computed tomography and chest computed tomography

The staging of non-small-cell lung cancer (NSCLC) to detect mediastinal lymph node (MLN) metastases is very important for determining the therapeutic strategy.

Methods: Thirty-four patients with proven NSCLC were enrolled in this study. All patients underwent chest computed tomography (CT) and technetium-99m (Tc-99m) tetrofosmin chest single photon emission computed tomography (SPECT) preoperative staging. Mediastinal lymph node metastases were determined on the basis of postoperative pathologic findings to compare the diagnostic accuracy of chest CT with that of Tc-99m tetrofosmin chest SPECT.

Results: Tc-99m tetrofosmin chest SPECT showed a diagnostic accuracy rate of 85.3% in detecting MLN metastases. Chest CT had an accuracy rate of 73.5%. If either Tc-99m tetrofosmin chest SPECT or chest CT with positive findings was considered as positive findings, the sensitivity was 94.7%. If either Tc-99m tetrofosmin chest SPECT or chest CT with negative findings was considered as negative, the specificity was 93.3%.

Conclusion: Tc-99m tetrofosmin chest SPECT was more accurate than chest CT in detecting MLN metastases in NSCLC patients. In addition, the combined use of Tc-99m tetrofosmin chest SPECT and chest CT could significantly increase the sensitivity and specificity compared with the single use of either Tc-99m tetrofosmin chest SPECT or chest CT.