New method of visualizing lymphatics in lung cancer patients by multidetector computed tomography

The aim of the present study was to investigate the safety and acceptability of a new method of visualizing lymphatics, including sentinel lymph nodes (SNs), in lung cancer patients using multidetector computed tomography (MDCT).

Images were obtained using an MDCT scanner (Asteion Multi 4 Detector-Row; Toshiba) at 1, 2, and 3 minutes after percutaneous injection of 1 mL contrast medium (iohexol) near the tumor in 15 patients with small peripheral lung cancers (cT1N0M0). A lymph node was confirmed to be an SN if the attenuation was more than 30 Hounsfield units greater on postcontrast images than on precontrast images. All patients underwent surgery, and definitive lymph node staging was assessed.

The procedure was performed safely in all patients without significant complications. Lymphatic ducts or lymph nodes were visualized in all 15 patients. The SN was identified in 14 of 15 patients (93.3%) at lymph node 14 in 4 patients, lymph node 13 in 7, lymph node 12 in 6, and lymph node 6 in 1. In 1 remaining patient, the lymphatic duct running from the tumor toward the pleura was visualized.

Lymphatics were visualized by this method in all patients without significant complications. This method should be useful not only to detect the SNs but to visualize pathways other than through the hilar lymph nodes.