Objective To analyze the diagnostic value of ¹⁸F-FDG PET/CT and enhanced CT in detecting metastatic lymph nodes of thoracic esophageal squamous cell carcinoma.

Methods Fifty-four patients with thoracic esophageal squamous cell carcinoma underwent both ¹⁸F-FDG PET/CT and enhanced CT before surgery within a week. All lesions were confirmed histopathologically as the golden standard. The sensitivity, specificity, and accuracy of the two imaging modalities were compared. In addition, the diagnostic accuracy of the two methods in detecting metastatic lymph nodes having different diameters in patients with thoracic esophageal squamous cell carcinoma was evaluated. Theχ²-test was used with SPSS 13.0.

Results A total of 186 lymph node specimens, including 77 specimens of metastases, were extracted and confirmed by pathology. The sensitivity, specificity, and accuracy of ¹⁸F-FDG PET/CT were 77.9%(60/77), 95.4%(104/109), 88.2%(164/186), respectively, whereas those of enhanced CT were 40.3%(31/77), 75.2%(82/109), and 60.8%(113/186), respectively. All values were statistically significant(χ²=24.04, 15.77, and 36.77, all P < 0.01). The diagnostic accuracy of ¹⁸F-FDG PET/CT is significantly better than that of enhanced CT in the group of R>5 mm (χ²=26.03 and 26.47, both P < 0.01) without the group of R≤5 mm(χ²=0.24, P>0.05).

Conclusion ¹⁸F-FDG PET/CT has a great value in detecting metastatic lymph nodes of thoracic esophageal squamous cell carcinoma, especially lymph nodes that are R>5 mm.