Esophageal Cancer: CT, Endoscopic US, and FDG PET for Assessment of Response to Neoadjuvant Therapy—Systematic Review

PURPOSE: To compare diagnostic accuracy of computed tomography (CT), endoscopic ultrasonography (US), and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for assessment of response to neoadjuvant therapy in patients with esophageal cancer by using a systematic review of the literature. MATERIALS AND METHODS: MEDLINE and EMBASE databases and Cochrane Database of Systematic Reviews were searched for relevant studies. Two reviewers independently assessed the methodological quality of each study. Summary receiver operating characteristic (ROC) analysis was used to summarize and compare the diagnostic accuracy of the three modalities. RESULTS: Four studies with CT, 13 with endoscopic US, and seven with FDG PET met inclusion criteria. Percentages of the maximum score in regard to methodological quality ranged from 15% to 100%. Summary ROC analysis could be performed for three studies with CT, four with endoscopic US, and four with FDG PET. The maximum joint values for sensitivity and specificity were 54% for CT, 86% for endoscopic US, and 85% for FDG PET. Accuracy of CT was significantly lower than that of FDG PET (P < .006) and of endoscopic US (P < .003). Accuracy of FDG PET and that of endoscopic US were similar (P = .839). In all patients, CT was always feasible, whereas endoscopic US was not feasible in 6% of the patients, and FDG PET was not feasible in less than 1%. CONCLUSION: CT has poor accuracy for assessment of response to neoadjuvant therapy in patients with esophageal cancer. Endoscopic US and FDG PET have equivalent good accuracy, but endoscopic US is not always feasible after chemotherapy and radiation therapy. FDG PET seems to be a promising noninvasive tool for assessment of neoadjuvant therapy in patients with esophageal cancer.