Positron emission tomography-computed tomography in predicting locoregional invasion in esophageal squamous cell carcinoma.

BACKGROUND: In order to clarify the role of positron emission tomography-computed tomography (PET/CT) in thoracic esophageal squamous cell carcinoma we investigated its value in predicting locoregional invasion.

METHODS: Forty-five patients receiving curative esophagectomy and lymph node dissection were included. The relationship between PET/CT findings and pathology results were studied. Correlation between nodal uptake and the modified lymph node staging, which is based on number of involved nodes (N0 = no nodes; N1 = 1 to 3 nodes; N2 = more than 3 nodes), was evaluated.

RESULTS: The mean maximal standardized uptake value (SUV(max)) was 5.09 +/- 4.00 in T1, 14.17 +/- 2.46 in T2, 13.32 +/- 3.96 in T3, and 10.37 +/- 1.94 in T4 primary tumor. The SUV(max) was significantly lower in stage T1 tumors than in stage T2 and T3 tumors. For regional nodal involvement, PET/CT findings significantly correlated with pathology results. However, the sensitivity, specificity, and accuracy of PET/CT were only 57.1%, 83.3%, and 71.1%, respectively, and even lower for detecting nonregional lymph node metastasis. When stratified by the modified staging system, the mean SUV(max) was 0.64 +/- 1.60 in N0, 1.43 +/- 2.08 in N1, and 4.67 +/- 4.32 in N2 regional lymph node metastases, and was significantly higher in patients with N2 metastasis than in patients with N0 and N1 metastases.

CONCLUSIONS: Locoregional invasion in esophageal cancer can be predicted by PET/CT. The SUV(max) of the primary tumor helped identify T1 tumor, and the SUV(max) of the regional lymph nodes correlated with the severity of nodal involvement.