PET/CT imaging in diagnosing lymph node metastasis of esophageal carcinoma and its comparison with pathological findings.

OBJECTIVE To investigate the usefulness of 18F-FDG PET/CT imaging in the diagnosis of lymph node metastasis of esophageal carcinoma and to compare its results with pathological findings. PATIENTS AND METHODS This study examined 43 cases of patients (32 males and 11 females, aged 54 ± 13 years old) being diagnosed with lymph node metastasis of esophageal carcinoma in our hospital between 2005 and 2014. All of these patients accepted 18F-FDG PET/CT imaging 10 days before the operation. Before reconstruction, each patient went through the body scan. PET/CT images were subject to comprehensive diagnostic analyses, by three experienced radiologists and/or professional nuclear physicians, on the number of metastatic lymph nodes and the maximum standardized uptake value (SUVmax). A control study was also performed on the pathological findings according to the latest esophageal cancer lymph node partition. RESULTS A total of 846 lymph nodes were taken out from the patients, among which 154 were confirmed with metastasis. When the SUVmax cutoff values were set at 2.5 and 5, 201 and 173 metastatic lymph nodes were found by 18F-FDG PET/CT imaging, respectively. Additionally, under such condition, 18F-FDG PET/CT imaging had the esophageal sensitivity of 69.48% vs 87.66%, specificity of 92.71% vs 94.51%, accuracy of 83.33% vs 93.26%, positive predictive value of 53.23% vs 78.03%, and negative predictive value of 92.71% vs 97.18%. CONCLUSIONS 18F-FDG PET/CT had high accuracy in imaging lymph node metastasis of esophageal cancer. SUVmax cutoff value of 5 had a higher diagnostic accuracy and should be recommended in clinical practice.