Evaluation of the Response to Chemotherapy in Advanced Gastric Cancer by Contrast-Enhanced Harmonic EUS

Background/Aims: In advanced gastric cancers, a significant correlation exists between the response to chemotherapy in primary gastric cancers and patient prognosis. Therefore, accurate evaluation of the response to chemotherapy in primary gastric cancers is important. We examined the response to chemotherapy in primary gastric cancers by contrast enhanced harmonic endoscopic ultrasonography (CEH-EUS). Methodology: Thirty-five patients with advanced gastric cancer underwent CEH-EUS. Among these patients, 19 patients with stage IV advanced gastric cancer who received chemotherapy and CEH-EUS more than twice were enrolled, and evaluated the response to chemotherapy in primary gastric cancers by CEH-EUS and endoscopy. Results: In PRs evaluated by endoscopic findings, echo intensity ratio (EIR) was decreased, and in PDs EIR was increased significantly by CEH-EUS. Five cases had difficulty in evaluating the response of primary gastric cancers to chemotherapy by endoscopy, while evaluation was possible in those 5 cases by CEH-EUS. Conclusions: CEH-EUS is a new method to evaluate responses to chemotherapy in primary gastric cancers not only by a change in size but also in tumor vascularity. Correct evaluation of primary gastric cancers by CEH-EUS help predicting prognosis of patients.