Computed tomography lymphography by transbronchial injection of iopamidol to identify sentinel nodes in preoperative patients with non–small cell lung cancer: A pilot study

Objective The objective of the present study was to assess the safety and feasibility of computed tomography lymphography by transbronchial injection of a water-soluble extracellular computed tomography contrast agent. Methods From April 2010 to May 2011, patients with clinical stage I non–small cell lung cancer who were candidates for lobectomy were enrolled in the present study. An ultrathin bronchoscope was inserted to the target bronchus under the guidance of virtual bronchoscopic navigation images. Computed tomography images of the chest were obtained 0.5 and 5 minutes after 2 or 3 mL of iopamidol was injected through a microcatheter. Sentinel nodes were identified when the maximum computed tomography attenuation value of the lymph nodes on the postcontrast computed tomography images increased by 30 Hounsfield units or more compared with the precontrast images. Patients underwent lobectomy with standard lymph node dissection. Results The ultrathin bronchoscope could access the targeted bronchus, and iopamidol was delivered into the peritumoral area in all 13 patients without any complications. Sentinel nodes were identified in 12 (92.3%) of the 13 patients. The average number of sentinel nodes was 1.5 (range, 1–2). Pathologic examination revealed metastatic lymph nodes in 2 patients. Metastatic nodes were included with the sentinel nodes. Conclusions Computed tomography lymphography by transbronchial injection of iopamidol was a safe and feasible method to identify the sentinel nodes in patients with clinical stage I non–small cell lung cancer.