Preoperative lymph node staging in esophageal cancer using integrated F-18 FDG PET/CT

Abstract

1483

Objectives: To evaluate the diagnostic value of FDG PET/CT and compare with enhanced CT (eCT) for preoperative lymph node staging in thoracic esophageal cancer patients.

Methods: 66 patients (M:F = 58:8, mean age=64) with thoracic esophageal squamous cell carcinoma underwent eCT and FDG PET/CT before radical esophagectomy. Node showing greater FDG uptake than background at PET/CT was considered positive for metastasis. At eCT, nodal size was considered positive for metastasis if the short axis measured >=5mm and this was compared with the general measure (>=10mm). To evaluate the combination of PET/CT and eCT, lymph node was regarded as metastatic node if any of two methods show the node to be positive. In addition, hounsfield unit (HU) of lymph node was measured at non-enhanced CT of PET/CT and high attenuation >=100HU was regarded as benign. The accuracy of each criterion was compared by the postoperative histologic result as reference standard.

Results: Total 417 nodal stations were dissected and 65 nodal stations proved to be metastasis. On a per-nodal station basis, the sensitivity, specificity, and accuracy of PET/CT were 43.1%, 86.6%, and 79.9%, respectively, whereas those of eCT>=5mm/eCT>=10mm were 56.9/35.4%, 76.4/93.5%, and 73.4/84.4%, respectively. When combining of PET/CT and eCT>=5mm, sensitivity, specificity, and accuracy were 61.5%, 75.6%, and 73.4%, respectively, and 56.9%, 84.7%, and 72.7% considering HU, respectively.

Conclusions: Sensitivity of PET/CT for nodal metastasis in esophageal cancer was improved by considering small-sized lymph node and specificity was improved by considering HU.