Clinical Implementations of Preoperative Computed Tomography Lymphography in Gastric Cancer: A Comparison with Dual Tracer Methods in Sentinel Node Navigation Surgery

Abstract

Current sentinel node (SN) detection techniques require a learning period and tracers have many disadvantages for practical use. The purpose of this study was to evaluate the feasibility of preoperative computed tomography (CT) lymphography using lipiodol for detecting SNs in gastric cancer. A total of 24 patients who underwent laparoscopic surgery for early gastric cancer were enrolled in this study. Noncontrast CT images were obtained 1-2 h after endoscopic submucosal peritumoral injection of 1 mL of lipiodol the day before surgery. The final sentinel basins (SBs) were decided by the dual tracer method (indocyanine green plus Tc-99m-antimony sulfur colloid) during laparoscopic gastrectomy. SN detection rate by preoperative CT lymphography using lipiodol and agreement between CT lymphography versus dual tracer method were evaluated. The agreement was confirmed with soft X-ray radiography of detected SBs. Technical failure of endoscopic lipiodol injection occurred in one patient. SNs were successfully detected in the remaining 23 patients (95.8 %), whereas the intraoperative SB detection rate using the dual method was 100 %. The agreement rate, defined as the concordance between two methods or inclusion of SNs detected by CT lymphography in SBs by the dual tracer method, was 87 %. Our initial experience of CT lymphography using lipiodol shows good potential in predicting SBs of gastric cancer preoperatively. However, SN detection by CT lymphography and the dual method should be applied complementarily in gastric cancer because discrepancies between these methods occur.