OBJECTIVES The objective of this study was to evaluate the scientific evidence currently available regarding the accuracy of PET-CT using 18F-FDG in the initial staging of patients with esophageal cancer.

METHODS We searched Medline (via Ovid), Embase, Lilacs, The Cochrane Library and Clinical Trials databases for studies that accessed the accuracy of PET-CT for detecting regional lymph nodes and distant metastases. Search strategies combined descriptors and free-text for PET scan, 18F-FDG, indication and esophageal cancer, with specific filters for diagnostic studies applied. Two reviewers screened all references by titles and abstracts and in full text, using a third reviewer in cases of disagreement. Articles published in English, Spanish or Portuguese, which enabled the reconstruction of 2x2 contingency tables, were included. Evidence was synthesized using mixed effects model (midas) in Stata12^®. Subgroup analyses by histological type were performed where data were available.

RESULTS After elimination of duplicates, 1,742 references were obtained, 132 were selected for evaluation in full text, and 61 studies for data extraction. Thirty-four studies were included in the quantitative analysis for PET-CT. On a per-patient analysis, pooled estimates for regional lymph node metastases showed sensitivity of 0.51 (95% CI 0.39-0.63), specificity of 0.90 (95% CI 0.87-0.92) and accuracy of 0.90 (95% CI 0.87-0.92) for all patients and, respectively, 0.50 (95% CI 0.37-0.62), 0.90 (95% CI 0.87-0.92) and 0.90 (95% CI 0.87-0.92) for squamous cell carcinoma. For distant metastases, pooled estimates showed sensitivity, specificity and accuracy of, respectively, 0.72 (95% CI 0.52-0.85), 0.95 (95% CI 0.88-0.98) and 0.93 (95% CI 0.90-0.95) for all patients.

CONCLUSIONS Evidence currently available suggests that PET-CT has overall high accuracy for detecting metastasis, despite its low sensitivity. The analysis suggests that PET-CT may be an important auxiliary tool in the diagnostic work-up of patients with esophageal cancer and may help determine better management strategies for these patients.