Chemoembolization of the lung improves tumor control in a rat model.

PURPOSE The novel method of organ-specific drug application we present here is unilateral chemoembolization of the lung by injecting the pulmonary artery with degradable starch microspheres and cytotoxic drugs to improve tumor control in lung metastases. EXPERIMENTAL DESIGN In a solitary metastasis rat model (CC531 adenocarcinoma), we studied the clinical and histological tumor response as well as subacute toxicity of the lung. Fourteen days after tumor induction, animals were randomized into five groups. Groups I and II served as controls. Group III received carboplatin i.v. (45 mg/kg). Isolated lung perfusion with buffered starch solution and carboplatin (15 mg/kg) was installed in group IV. Chemoembolization with carboplatin (15 mg/kg) was performed in group V. RESULTS Seven days later, the difference in the tumor volume before and after treatment was +422 mm(3) (+/-226) in group I, +697 mm(3) (+/-423) in group II, +70 mm(3) (+/-31) in group III, -8 mm(3) (+/-17) in group IV, and -17 mm(3) (+/-16) in group V (P < 0.05 groups IV and V versus groups I, II, and III). No pleural spread was observed in groups IV and V. Histologically, the area of tumor necrosis was largest in group IV. Mild alveolar cell hyperplasia, pulmonary edema, and hemorrhage without subacute fibrotic changes were noted in all groups. CONCLUSION This is the first study to perform chemoembolization of the lung. Compared with i.v. therapy, chemoembolization was more effective without serious toxicity. Its efficacy was comparable with that of isolated lung perfusion but less stressful for a possible clinical application.