Development of Endoscopic CT Lymphography for Mapping Sentinel lymph node in esophageal cancer

评价内镜下计算机断层淋巴显像（CTLG）技术与粘膜下注射一种广泛使用的造影剂iopamidol直接显示狗和可手术食管癌患者引流淋巴通路的可行性。经该机构动物委员会批准，采用柔性内窥镜将未稀释的碘帕美醇共2 ml注射到9只麻醉犬的食管（n = 6）或胃（n = 3）粘膜下层。在注射造影剂前和注射后10分钟分别获得1.25 mm厚的多排CT图像。这些动物被安乐死以检查淋巴解剖。经伦理委员会批准和患者知情同意，9例可手术食管癌患者同样行CTLG，但在CTLG指导下瘤周注射2 ml iopamidol，食管切除术和区域淋巴结清扫。对包括sln在内的清扫淋巴结进行组织病理学检查。在所有受试者中，CTLG在注射造影剂后5分钟内就能显示引流淋巴管与增强/未增强淋巴结（即前哨淋巴结（sln））的直接连接，观察者之间具有一致性。在CT-LG的指导下，犬的13个sln（每只动物1.4个淋巴结）和患者的18个sln（每只患者2个淋巴结）都能被发现并在正确的位置切除。在患者中，组织病理学检查显示ctg引导下SLN活检成功的可能性；3例患者仅术前确定的一个淋巴结转移呈阳性，2例患者的淋巴结转移和邻近淋巴结转移均呈阳性，其余4例患者的所有切除淋巴结转移均为阴性。内镜下CTLG可以直观地看到sln与引流淋巴管的直接连接和准确的解剖定位。

To evaluate the feasibility of endoscopic computed tomographic lymphographic (CTLG) technique with submucosal injection of a widely-available contrast agent iopamidol for direct visualization of drainage lymphatic pathways in dogs and in patients with operable esophageal cancer. With approval by the institution's animal committee, a total of 2 ml undiluted iopamidol was injected into esophageal (n = 6) or gastric (n = 3) submucosa in 9 anesthetized dogs, using a flexible endoscopy. The 1.25-mm thick multidetector-row CT images were obtained prior to contrast injection and during 10 min after injection. These animals were euthanized to examine lymphatic anatomy. With approval by ethical committee and informed consent from patients, 9 patients with operable esophageal cancer similarly underwent CTLG, but with peritumoral injection of 2 ml iopamidol, followed by esophagotectomy and regional lymph node dissection under CTLG guidance. Histopathology of dissected nodes including SLNs was examined. CTLG visualized the direct connection of the drainage lymphatic vessels and enhanced/unenhanced nodes [i.e., sentinel lymph nodes (SLNs)] as early as within 5 min after contrast injection in all subjects, with an interobserver consistency. All 13 SLNs in dogs (1.4 nodes per animal) and 18 SLNs in patients (2 nodes per patient) could be found and dissected at the correct location under CT-LG guidance. In patients, histopathological examination indicated successful probability of CTLG-guided SLN biopsy; metastasis was positive only in one of the preoperatively identified SLNs in 3 patients and in both SLNs and adjacent nodes in 2 patients, and negative in all resected nodes in the remaining 4 patients. Endoscopic CTLG is feasible for visualizing direct connection and accurate anatomic location of SLNs and drainage lymphatic vessels.