Preoperative Imaging of Sentinel Lymph Nodes in Gastric Cancer Using CT Lymphography

Abstract

PurposePreoperative identification of the sentinel lymph node (SLN) in gastric cancer (GC) patients may have great advantages for the minimally invasive treatment. This study was performed to evaluate the possibility of preoperative SLN detection using CT lymphography.Materials and MethodsFourteen patients with early GC were enrolled. CT images were obtained before and at 1, 3, and 5 minutes after endoscopic submucosal peritumoral injection of 2 mL iopamidol. For patients with clearly identified SLNs, to make comparisons with the CT lymphography results, intraoperative SLN detection was performed using subserosally injected Indocyanine green (ICG) lymphography and ex vivo ICG and iopamidol lymphography using mammography was also performed.ResultsCT lymphography clearly visualized draining lymphatics and SLNs in 4 (28.6%) out of 14 patients. All clearly visualized SLNs (one to three SLNs per patient) under preoperative imaging were detected in the same location by intraoperative ICG lymphography and ex vivo ICG and iopamidol lymphography using mammography. All preoperative SLN detections were observed with the primary tumors in the lower third of the stomach.ConclusionAlthough our study demonstrated a SLN detection rate of less than 30%, CT lymphography with radio-contrast showed potential as a method of preoperative SLN detection for GC.

Nanoscale iodized oil emulsion: a useful tracer for pretreatment sentinel node detection using CT lymphography in a normal canine gastric model

“…Thus, if we could identify patients with LN metastases by SLN detection prior to ESD, we may save these patients from an unnecessary gastrectomy. However, no reliable method for preoperatively detecting SLNs in gastric cancer has been established, and current CT lymphography using radiocontrast has yielded contradictory results [15,17].…”

“…In most of these attempts, commercially available, water-soluble non-particulate iodine contrast agent was used as a tracer [14][15][16][17]. However, CT lymphography using water-soluble non-particulate iodine contrast agent in gastric cancer patients has shown considerable differences in the detection rates of SLNs (28.6-83.3%) [15,17].…”

“…However, no reliable method for the preoperative detection of SLNs in gastric cancer has been established. Additionally, current CT lymphography using radio-contrast agents has yielded contradictory results [15,17].…”

“…Preoperative SLN mapping via interstitial computed tomographic (CT) lymphography using radio-contrast agents is gaining interest because it may increase the detection rate of SLNs intraoperatively and it gives accurate anatomical information on SLNs [14][15][16][17]. Pretreatment identification of the SLNs in gastric cancer patients using CT lymphography may have great advantages for minimally invasive surgery.…”

A Review of Techniques for Sentinel Lymph Node Mapping with Special Reference to the Head and Neck Region

“…55,56 MRI lymphography has been used for SLN detection mainly in breast, 57 and pelvic tumors. 58 One feature of these techniques is the possibility of differentiating between benign and malignant nodes depending on the node's imaging pattern.…”