CT lymphography-navigated sentinel lymph node biopsy in patients with superficial esophageal cancer

To evaluate experimentally and clinically the feasibility of a newly developed technique of endoscopic computed tomography (CT) lymphography with endoscopic submucosal injection of iopamidol for esophageal sentinel lymph node (SLN) mapping and biopsy examination.

Nine anesthetized dogs underwent CT after endoscopic submucosal injection of 2 mL iopamidol; 1.25-mm thick CT images were obtained before and at 1, 3, 5, 7, and 10 minutes after contrast injection. Clinically, 12 patients with superficial esophageal cancer (preoperative imaging stage: cT1, cN0) underwent CT lymphography in a similar fashion at 1, 5, and 10 minutes after peritumoral injection, followed by radical esophagectomy and regional lymph node dissection under CT lymphography guidance.

CT lymphography visualized the draining lymphatic vessels and SLNs within 5 minutes after contrast injection. All 14 SLNs in dogs (average, 1.5 nodes per animal; range, 1-2) and 28 SLNs in patients (average, 2.3 nodes per patient; range, 1-4) were found intraoperatively at the correct location under CT lymphography guidance. Lymph node metastasis could be detected with excellent sensitivity and accuracy in this small number of patients with no false-negative findings; metastasis was positive only in the preoperatively identified SLNs in 4 patients and in both SLNs and distant nodes in 1 patient, and was negative in all resected nodes in the remaining 7 patients.

Endoscopic CT lymphography appears to allow accurate identification of direction and locations of lymph flow and SLNs, and has the potential clinical applicability for esophageal SLN mapping and biopsy examination, but will require a large study to determine its accuracy and usefulness.