Limited additional value of cervical ultrasonography over a negative 18F-FDG PET/CT for diagnosing cervical lymph node metastases in patients with esophageal cancer: a systematic review and meta-analysis

Abstract

Objective To assess the additional value of cervical ultrasonography as supplement to a negative fluorine- 18-fluorodeoxyglucose ( 18F-FDG) PET/computed tomography (CT) for detecting cervical lymph node metastases during the initial staging of patients with esophageal cancer. Methods PubMed/Medline, Embase, and the Cochrane library were systematically searched. The analysis included diagnostic studies describing the accuracy of cervical ultrasonography and integrated 18F-FDG PET/CT or standalone 18F-FDG PET and CT for detecting cervical lymph node metastases in patients with esophageal cancer. The reference standard consisted of cytopathology and/or clinical follow-up. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality of the included studies. A random effects model was used to meta-analyze the additional diagnostic value of cervical ultrasonography. Results Four diagnostic studies were eligible and included for meta-analysis, comprising 567 patients with esophageal cancer who underwent diagnostic workup before treatment. The quality of the included studies was considered reasonable; there were few concerns regarding risk of bias and applicability. In three of the four studies, cervical ultrasonography did not detect cervical lymph node metastases in addition to a negative finding on 18F-FDG PET/CT or standalone 18F-FDG PET and CT. In one study, cervical ultrasonography detected additional cervical lymph node metastases in 4% (3/74) of patients over standalone 18F-FDG PET and CT. Pooled estimate of the additional value of cervical ultrasonography was 1% (95% confidence interval: 0-5%). Conclusion Cervical ultrasonography has very limited additional diagnostic value as supplement to a negative 18F-FDG PET/CT in the detection of cervical lymph node metastases during the initial staging of patients with esophageal cancer.