Diagnostic performance of computed tomography short-axis diameter for supraclavicular lymph node metastasis after neoadjuvant chemotherapy for esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) often metastasizes to supraclavicular lymph nodes (SCLNs), which are potentially curable distant metastases by SCLN dissection during esophagectomy. Prophylactic SCLN dissection should be based on an accurate preoperative assessment of SCLN metastasis. We evaluated 199 patients who received neoadjuvant chemotherapy, followed by esophagectomy with three-field lymph node dissection for ESCC. For each patient, the largest SCLN was measured on the left and right sides. Long- and short-axis diameters of 398 SCLNs were measured using computed tomography (CT), and long-to-short-axis ratio was calculated. Diagnostic accuracies of the long- and short-axis diameters and long-to-short-axis ratio were determined using area under the curve (AUC) of the receiver operating characteristic plot. Of the 199 patients, 16.6% had pathological SCLN metastasis. AUCs of the short-axis diameter had the most significant values in the left and right sides compared with the other variables, at 0.93 (95% confidence interval [CI]: 0.89-0.97) for the left side and 0.92 (95% CI: 0.87-0.97) for the right side. When the short-axis diameter was <5 mm after chemotherapy, negative predictive value was sufficiently high (99.4% and 98.2% for the left and right SCLNs, respectively). In contrast, when the diameter exceeded 8 mm, positive predictive value increased to 71.4% and 83.3% in the left and right SCLNs, respectively. The short-axis diameter of the largest SCLN on CT after neoadjuvant chemotherapy appears to be a helpful indicator for diagnosing SCLN metastasis in patients with ESCC after neoadjuvant chemotherapy.