Endoscopic Ultrasound Versus CT Scan for Detection of the Metastases to the Liver

BACKGROUND: Computed tomography (CT) scan is a standard test for the detection of the liver metastases; however, metastases are often missed on the CT scan. OBJECTIVE: To compare the accuracy of the endoscopic ultrasound (EUS)/endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with CT scan for detection of the liver metastases. DESIGN: Prospective study. PATIENTS: Subjects with newly diagnosed tumors of the lung, pancreas, biliary tree, esophagus, stomach, and colon were enrolled. INTERVENTIONS: A CT scan and EUS examination of the liver was performed. EUS-FNA was performed on noncystic liver lesions. RESULTS: One hundred thirty-two cases were enrolled. The presence of liver metastasis was established in 26 cases. The diagnostic accuracy of EUS/EUS-FNA and CT scan was 98% and 92%, respectively (P=0.0578). In comparison to CT scan, EUS detected significantly higher number of metastatic lesions in the liver (40 vs.19; P=0.008). CT scan detected lesions in liver that were too small to be characterized in 8 cases (malignant-3; benign-5). Of these, EUS-FNA correctly characterized the lesion to be malignant in 3/3 cases and benign in 4/5 cases. No complications were observed as a result of EUS-FNA. LIMITATIONS: Endoscopist was not blinded to the findings of the CT scan. CONCLUSIONS: In comparison with the CT scan, there was trend in favor of EUS/EUS-FNA for the superior diagnostic accuracy. EUS was distinctly superior to the CT scan in detecting the number of metastatic lesions. EUS-FNA was also useful to identify the nature of lesions that were too small to be characterized on the CT scan.