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Background: Isolated lung perfusion (ILuP) is an experimental technique for the treatment of pulmonary metastases. We hypothesized that part of the drug taken up by the lung during ILuP is washed out during the flush procedure. Therefore, we investigated gemcitabine uptake at different inflow concentrations, and the effect of delayed clamp release after ILuP on lung levels was studied., Methods: Thirty rats had ILuP during 30 minutes using gemcitabine perfusate levels of 1.3, 2.7, 4.0, 5.3, and 6.7 mg/mL. Another 37 rats underwent ILuP with gemcitabine perfusate levels of 6.7 mg/mL during 6 minutes followed by a 5-minute flush and 30 or 60 minutes of reperfusion, while two other groups had ILuP and delayed clamp release for 30 or 60 minutes followed by a 5-minute flush. All effluent and lung samples were stored for later analysis. Results were evaluated using Friedmann two-way analysis and two-way analysis of variance., Results: At 6 minutes, steady-state of gemcitabine uptake was achieved for all inflow concentrations and a linear relation (r = 0.933, p < 0.0001) between effluent and lung levels was observed. Delayed clamp release resulted in significantly higher lung levels compared with immediate restoration of blood circulation after ILuP (456% at 30 minutes and 828% at 60 minutes)., Conclusions: Effective gemcitabine lung levels are already achieved after 6 minutes of ILuP with 6.7 mg/mL followed by delayed clamp release during 30 minutes instead of the clinically applied 30 minutes ILuP.

Background: Current 5-year survival after complete resection of pulmonary metastases is 20% to 40%, and many patients develop intrathoracic recurrences. Isolated lung perfusion is an experimental technique to deliver high-dose chemotherapy to the lung without systemic exposure. A phase I trial of isolated lung perfusion with melphalan (MN) combined with pulmonary metastasectomy for resectable lung metastases was conducted to define the dose-limiting toxicity and maximum tolerated dose., Methods: From May 2001 to August 2003, 16 patients underwent isolated lung perfusion with MN, followed by surgical resection of lung metastases. Patients were treated with increasing MN doses (15, 30, 45, and 60 mg). For each dose level, normothermia (37 degrees C) and hyperthermia (42 degrees C) were evaluated (n = 3 per level). Serum samples were obtained during the procedure. Pulmonary, hematologic, and nonhematologic toxicities were recorded. The primary tumor was colorectal in 7 patients, renal in 5, sarcoma in 3, and salivary gland in 1. Isolated lung perfusion was performed unilaterally in 11 patients, and staged bilaterally in 5., Results: In total, 21 procedures of isolated lung perfusion with complete metastasectomy were performed without technical difficulties. Operative mortality was 0%, and no systemic toxicity was encountered. Grade 3 pulmonary toxicity developed at a dose of 60 mg of MN at 37 degrees C in 2 of 3 patients at this dose, terminating the trial., Conclusions: Isolated lung perfusion with MN combined with pulmonary metastasectomy is feasible. Dose-limiting toxicity occurred at a dose of 60 mg of MN at 37 degrees C, and the maximum tolerated dose was set at 45 mg of MN at 42 degrees C.

Background: Isolated lung perfusion (ILuP) proved to be superior for the treatment of lung metastases compared with intravenous (i.v.) injection. However its invasive character limits repetitive treatment. Blood flow occlusion (BFO) as a regional therapy with gemcitabine (GCB) was evaluated in a rat model. Lung levels of GCB were examined with different exposure times and flow rates and compared with ILuP and i.v.. Cell kill was studied in vitro., Methods: In vitro survival of CC531 adenocarcinoma cells was determined after 10, 20, and 40 minutes of exposure to GCB. In vivo 48 Wag/Rij rats underwent BFO with GCB at a rate of 0.2 mL/min and 0.5 mL/min during 10, 20, 30, and 40 minutes. Statistical analysis was performed using Student's t test., Results: In vitro, the dose of GCB resulting in 50% growth inhibition was 9.1 microg/mL, 7.2 microg/mL, and 2.2 microg/mL after 10, 20, and 40 minutes exposure respectively. In vivo, no significant difference in lung levels of GCB was observed between a flow rate of 0.2 mL/min compared with 0.5 mL/min at any exposure time point (p < 0.05). Lung tissue was saturated after 20 minutes. Blood flow occlusion resulted in a lower plasma levels and higher lung levels of GCB compared with i.v. injection of the maximal tolerated dose of 40 mg., Conclusions: Growth inhibition of CC531 cells in vitro increased with exposure time while lung tissue was saturated after 20 minutes of BFO. No difference in GCB lung levels were seen after BFO compared with ILuP. Systemic exposure after i.v. injection was higher compared with BFO but did not result in higher lung levels.

Background: Isolated lung perfusion (ILuP) with melphalan (MN) is superior to intravenous infusion for the treatment of pulmonary carcinoma and sarcoma metastases. However, it is unknown whether a bolus injection of MN into the perfusion circuit or ILuP with a fixed concentration of MN will result in the highest lung levels., Methods: ILuP with 0.5 mg MN was performed in Wag-Rij rats for 30 minutes either by a single-pass system (SP) (fixed concentration) (n = 10) or by reperfusion (RP) (bolus injection) (n = 10). In a separate experiment, rats were perfused with blood as the perfusate. In a third experiment, tumor levels were compared between SP, RP, or intravenous therapy with a dose of 0.5 mg. For induction of pulmonary metastases, 0.5 x 10(6) single adenocarcinoma cells were injected intravenously and therapy was given on day 30. For comparison of drug concentrations, unpaired Student's t test was applied. Statistical significance was accepted at p less than 0.05., Results: Lung perfusion studies were succesfully performed without systemic leakage. Temperature of perfusate and rats was 34 degrees C to 37 degrees C. A significantly higher hematocrit (mean 27.9) compared with buffered starch (mean 2.5) did not result in higher MN lung levels or lower wet-to-dry ratio. Tumor levels were significantly higher after ILuP compared with intravenous therapy. However, no difference in tumor and lung levels was seen between single-pass and reperfusion., Conclusions: Both ILuP techniques resulted in significantly higher MN lung levels than after intravenous therapy. Because no difference was seen between single-pass and recirculating perfusion, MN can be injected as a bolus into the closed perfusion circuit.

Background: Isolated left lung perfusion with melphalan and human tumor necrosis factor-alpha for pulmonary metastatic adenocarcinoma in the WAG/Rij rat was studied., Methods: Survival was determined for melphalan, human tumor necrosis-alpha. Lung, pulmonary effluent, and serum melphalan were analyzed by chromatography after isolated lung perfusion or intravenous injection. On day 0, rats were injected with 2.0 x 10(6) CC531S cells intravenously. On day 7, rats underwent sham thoracotomy, received melphalan intravenously, or underwent isolated left lung perfusion with saline, melphalan, tumor necrosis factor, and a combination of the latter two. On day 14, tumor nodules were counted., Results: For the doses of 400 microg tumor necrosis factor, 1,000 microg tumor necrosis factor, or both melphalan and tumor necrosis factor (2 mg + 200 microg), survival rates after contralateral pneumonectomy were 33%, 17%, and 80%, respectively. Survival in all other groups was 100%. Left lung melphalan level was significantly higher after isolated lung perfusion compared to intravenous administration. Significantly fewer left lung nodules were found for 0.5 mg isolated lung perfusion with melphalan (28+/-17) compared to isolated administration (200+/-0) (p = 0.001), and for 1.0 mg intravenous lung perfusion with melphalan (16+/-10) compared to controls (171+/-65) (p = 0.00047). Tumor necrosis factor showed no significant effect., Conclusions: Isolated lung perfusion with melphalan is an effective treatment for pulmonary metastases from adenocarcinoma in the rat.