Isolated lung perfusion with melphalan for the treatment of metastatic pulmonary sarcoma.

ABSTRACT

OBJECTIVE: Isolated lung perfusion allows the delivery of high-dose chemotherapy to the perfused lung and is an efficacious modality in the treatment of pulmonary metastases in the rat. Melphalan activity in this model was investigated. METHODS: TOXICITY STUDY Maximum tolerated dose of melphalan delivered by means of isolated lung perfusion was determined by survival after contralateral pneumonectomy. PHARMACOKINETICS STUDY Nineteen rats were treated with melphalan administered either by isolated lung perfusion (2 mg) or intravenously (2 mg or 1 mg). Lung, pulmonary effluent, and serum melphalan were analyzed by high-pressure liquid chromatography. EFFICACY STUDY On day 0, 41 rats received an intravenous injection of 5 x 10(6) methylcholanthrene induced sarcoma cells. On day 7, rats either received intravenous melphalan (2 mg [n = 10]; 1 mg [n = 8]) or underwent left isolated lung perfusion with 2 mg of melphalan (n = 12). Isolated lung perfusion with buffered hetastarch in sodium chloride (Hespan, n = 11) was used as control. On day 14, pulmonary nodules were counted. TOXICITY Maximum tolerated dose of melphalan delivered buy means of isolated lung perfusion was 2 mg. PHARMACOKINETICS Left lung melphalan level was significantly higher in the isolated lung perfusion group (62.2 +/- 34.3 microg/gm lung) than in the intravenous treatment groups (6.9 +/- 1.9 microg/gm lung and 3.3 +/- 0.9 microg/gm lung, respectively) (p = 0.0002). EFFICACY Significantly fewer left lung nodules were found in animals receiving melphalan by means of isolated lung perfusion (7 +/- 10) than in the groups receiving intravenous melphalan (60 +/- 21) or buffered hetastarch by isolated lung perfusion (84 +/- 52) (p = 0.01 and p = 0.0001, respectively). CONCLUSION: Isolated lung perfusion with melphalan is safe and effective in the treatment of pulmonary sarcoma metastases in the rat.