Novel Drug Delivery Method Targeting Para-Aortic Lymph Nodes by Retrograde Infusion of Paclitaxel into Pigs' Thoracic Duct.

Gastrointestinal cancer with massive nodal metastases is a lethal disease. In this study, using a porcine model, we infused the anti-cancer drug Paclitaxel (PTX) into thoracic ducts to examine the efficiency of drug delivery to intra-abdominal lymph nodes. We established a technical method to catheterize the thoracic duct in the necks of pigs. We then compared the pharmacokinetics of PTX administered intrathoracically with those of systemic (intravenous) infusion. Serum, liver, and spleen concentrations of PTX were significantly lower following thoracic duct (IT) infusion than after intravenous (IV) administration approximately 1-8 h post-infusion. However, PTX levels in abdominal lymph nodes were maintained at relatively high levels up to 24 h after IT infusion compared to after IV infusion. Concentrations of PTX in urine were much higher after IT administration than after IV administration. After IT infusion, the same concentration of PTX was obtained in abdominal lymph nodes, but the serum concentration was lower than after systemic infusion. Therefore, IT infusion may be able to achieve higher PTX doses than IV infusion. IT delivery of anti-cancer drugs into the thoracic duct may yield clinical benefits for patients with extensive lymphatic metastases in abdominal malignancies.