Enhanced intensity on preoperative double contrast-enhanced sonography as a useful indicator of lymph node metastasis in patients with gastric cancer.

OBJECTIVES:The aim of this study was to investigate the predictive value of enhanced intensity on double contrast-enhanced sonography in assessing lymph node metastasis of gastric cancer. METHODS:A total of 357 patients with gastric cancer were enrolled in this study. Double contrast-enhanced sonography, in which an oral ultrasound contrast agent is combined with an intravenous contrast agent, was performed preoperatively, and the data were analyzed quantitatively. The predictive ability of enhanced intensity, a quantitative double contrast-enhanced sonographic measure, for lymph node metastasis was evaluated retrospectively. RESULTS:Compared to negative lymph node metastasis cases, the presence of thicker lesions, deeper invasion, poorer differentiation, and higher enhanced intensity were found in positive cases (P< .05). An enhanced intensity cutoff value of 16.91 dB was the best point for balancing the sensitivity and specificity (71.50% and 79.30%, respectively) for prediction of lymph node metastasis, with the highest Youden index of 0.508. The area under the receiver operating characteristic curve was 0.828 (P < .001; 95% confidence interval, 0.786-0.870). In cases in which the lesions were hyperenhanced (enhanced intensity >16.91 dB), the lesions were significantly thicker and had deeper invasion, poorer differentiation, and more positive metastasis findings compared to non-hyperenhanced cases (enhanced intensity ≤16.91 dB; P < .05). On logistic regression analysis, the enhanced intensity of primary tumors and the invasion depth were significantly associated with lymph node metastasis. CONCLUSIONS:Double contrast-enhanced sonography with quantitative analysis may be considered a novel alternative imaging modality for noninvasive preoperative evaluation of lymph node metastasis with good reliability.