Detection of sentinel nodes by a novel red-fluorescent dye, ATX-S10Na (II), in an orthotopic xenograft rat model of human gastric carcinoma

Background and Objective We developed a new imaging system to detect sentinel nodes (SNs) using a novel fluorescent tracer, ATX‐S10Na(II), and investigated its usefulness in an animal model. Study Design/Materials and Methods Human gastric carcinoma cells were implanted orthotopically into nude rats. ATX‐S10Na(II) was injected subserosally into the primary tumor lesion, and visualized by a fluorescence spectro‐laparoscope. Presence of tumor cells in lymph nodes (LNs) was determined by RT‐PCR specific for human β‐actin. Results Injection of ATX‐S10Na(II) was successful in 27 tumor‐bearing rats. A red fluorescence was incorporated into the left gastric and hepatic LNs in 25 and 2 rats, respectively. Of note, human β‐actin was detected in most of these LNs. Fluorescence was not detected in LNs that did not contain cancer. Conclusion ATX‐S10Na(II) is useful for the detection of cancer‐containing SNs in an animal model of gastric carcinoma, and may serve as a novel tracer in SN navigation surgery. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.