Does [18F] fluorodeoxyglucose-positron emission tomography/computed tomography have a role in cervical nodal staging for esophageal squamous cell carcinoma?

Objective: Accurate nodal staging is crucial for esophageal cancer. A prospective study was performed to assess the value of [18F] fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for diagnosing cervical lymph node metastasis (LNM) of esophageal squamous cell carcinoma.

Methods: From June 2018 to November 2018, 110 patients with resectable esophageal cancer were prospectively enrolled. Esophagectomy with 3-field lymphadenectomy was performed after FDG-PET/CT scanning. The primary end point was cervical LNM determined via postoperative histologic examination. The sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), and accuracy (AC) of FDG-PET/CT for the assessment of LNM were determined using histologic results as reference standards.

Results: Positive lymph nodes as determined via FDG-PET/CT were detected in 61 patients (55.5%), of whom 13 (11.8%) had positive cervical lymph nodes. After surgery, 59 patients (53.6%) exhibited pathologic LNM, of whom 20 (18.2%) had cervical LNM. SE, SP, PPV, NPV, and AC were 65.6%, 61.2%, 67.8%, 58.8%, and 63.6%, respectively, with regards to diagnosing overall LNM, and were 45.0%, 95.6%, 69.2%, 88.7%, and 86.4%, respectively, for diagnosing cervical LNM. Of the 110 patients, 90 underwent both FDG-PET/CT scanning and ultrasonography in the neck, and there were no significant differences in SE, SP, PPV, NPV, or AC with respect to cervical LNM diagnosis between FDG-PET/CT and ultrasonography.

Conclusions: For cervical LNM of esophageal squamous cell carcinoma, FDG-PET/CT scanning exhibited high specificity but low sensitivity, suggesting that it is of limited value for this purpose.