563. MAGNETIC DETECTION OF ESOPHAGEAL SENTINEL LYMPH NODES – A PROOF OF CONCEPT STUDY IN A PORCINE MODEL

Abstract Superparamagnetic iron oxide particles (SPIONs) have been used to mark sentinel lymph nodes in breast and prostate cancer surgery. Their suitability for other tumor entities remains unclear. In esophageal surgery, the future focus may shift to tailored lymph node resection to reduce the extent of surgery and to minimize perioperative complications. Still, there are very few tracers available to detect draining lymph nodes. In this study, we investigated the suitability of SPIONs for this issue. Seven male piglets underwent surgery and SPIONs were injected into the esophageal wall. The distribution of the tracer into the adjacent local lymph nodes was investigated by a magnetometer over 120 minutes. Then, the specimens were harvested and examined histologically. SPIONs were detected in all cases in the draining lymph nodes within the first 5 minutes after injection reaching a positive magnetic signal at 2160 ± 422 (magnetic count). The maximum was reached after 15 minutes at the magnetic count of 4880 ± 554. The histological specimen confirmed the presence of the tracer in the esophageal wall and in the draining lymph nodes. SPIONs are suitable for the detection of esophageal lymph nodes and should be evaluated in the clinical setting.