Isolated lung perfusion with platinum in the treatment of pulmonary metastases from soft tissue sarcomas

Reversible occlusion of the pulmonary vasculature by transarterial embolisation with degradable starch microspheres: preclinical assessment in a human isolated lung perfusion model

BACKGROUND

Transpulmonary embolisation (TPE) using degradable starch microspheres (DSM) is a potential approach to treat pulmonary metastases. However, there is a paucity of detailed information on perfusion dynamics. The aim of this study was to establish a human ex vivo isolated lung perfusion (ILP) model to observe and evaluate the effects of DSM-TPE in a near-physiologic setting.

METHODS

ILP was carried out on six surgically resected lung lobes. At baseline, computed tomography (CT), including CT perfusion imaging (CTPI), and histopathological sampling were performed (t30). DSM-TPE was initiated and increased stepwise (t45, t60, t75, and t90) to be followed by CT imaging, histopathological sampling, and pulmonary arterial pressure (PAP). After the last assessment (t90), alpha-amylase was injected into the pulmonary artery to allow for DSM hydrolysation and two additional assessments (t105; t120). Histopathological specimens were evaluated using a semiquantitative ordinal score. CTPI was used for time to peak (TTP) analysis.

RESULTS

After DSM administration, PAP and TTP increased significantly: PAP slope 95% confidence interval (CI) 0.104-0.483, p = 0.004; TTP t30 versus t45, p = 0.046. After the addition of alpha-amylase, functional parameters reverted to values comparable to baseline. In histopathological samples, embolisation grades increased significantly until t90 (slope 95% CI 0.027-0.066, p < 0.001) and decreased after addition of alpha-amylase (slope 95% CI -0.060-0.012, p = 0.165), CONCLUSIONS: The ILP model demonstrated successfully both the physiologic effect of DSM-TPE on human lungs and its reversibility with alpha-amylase. Thus, it can be used as a near-physiologic preclinical tool to simulate and assess later clinical approaches.

Assessment of combined modality therapy for non-small-cell lung carcinoma: A simulation study concerning concurrent chemo-brachytherapy

Although surgery is the treatment of choice for early-stage non-small-cell lung carcinoma, almost two-thirds of patients do not have acceptable pulmonary function for extensive surgeries. The alternative approach for this large group of patients is sublobar resection along with low-dose-rate (LDR) brachytherapy (BT). However, patients with resected lungs have a high risk of recurrence and are often treated with platinum-based (Pt-based) chemotherapy (CT). In this study, we aimed to evaluate the absorbed doses of lung and other thoracic organs, considering concurrent chemo-BT with LDR sources in two modalities: conventional vs. unconventional Pt-based CT. We used the MCNPX code for simulations and to obtain the lung absorbed dose, dose enhancement factor (DEF), and Pt threshold concentration for the abovementioned modalities. Our results indicate that DEF correlates directly with Pt concentration at prescription point and is inversely correlated with depth. Dose enhancement for conventional CT concurrent with BT is <2%, while it is >2% in case of unconventional Pt-based CT wherein the Pt concentration exceeds 0.2 mg/g lung tissue. Also, the absorbed dose of healthy thoracic organs decreased by 2-11% in the latter approach. In conclusion, the concurrent chemo-BT in the lung environment could enhance the therapeutic doses merely by using unconventional CT methods, while lung Pt accumulation exceeds 0.2 mg/g.

High Prevalence of 5T4/Trophoblast Glycoprotein in Soft Tissue Sarcomas

The expression of 5T4/trophoblast glycoprotein was evaluated in several histological subtypes of soft tissue sarcoma (STS) to determine whether the prevalence and level of expression of this membrane-associated glycoprotein is sufficient for use in targeted therapies. Tumor tissue microarrays containing cores from different histological subtypes of STS were stained using a standardized immunohistochemical staining method to detect 5T4; the level of staining was assessed using a semi-quantitative scoring method. No 5T4 staining was seen in the angiosarcomas and liposarcomas investigated in this study. 5T4 staining in the other STS subtypes was seen in more than 50% of cases, warranting further investigation into whether this antigen could evoke an anti-tumor immune response or can be used as target for the delivery of more potent toxins through antibody drug conjugates.

Isolated lung perfusion for pulmonary metastases, a review and work in progress

Pulmonary metastasectomy is a widely accepted treatment for many patients with pulmonary metastases from various solid tumors. Nevertheless, 5–year survival is disappointing, with rates of 25–40%, and many patients develop recurrences. Isolated lung perfusion (ILuP) is a promising new technique to deliver high–dose chemotherapy to the lungs, while minimising systemic toxicities. This procedure is technically safe and feasible; however, clinical value and efficacy remain unclear. The aim of this paper is to give a review of literature on ILuP in humans, and to describe the development of the perfusion procedure in our institute.

Isolated Lung Perfusion for Pulmonary Metastases

Isolated lung perfusion (ILP) is a surgical technique developed to treat pulmonary metastases. During ILP, high-dose chemotherapy is delivered into the pulmonary vasculature, minimizing systemic exposure and delivering the chemotherapeutic agent directly to the lung. ILP has been studied extensively in a variety of animal models and in humans in phase I trials. The most frequently studied chemotherapeutic agents used in ILP are doxorubicin, 5-flurodeoxyuridine, tumor necrosis factor-α, paclitaxel, melphalan, gemcitabine, and cisplatin. Phase I clinical trials with ILP have shown that ILP can be safely performed in humans but with mixed clinical results and poor long-term survival.

Regional chemotherapy of the lung: transpulmonary chemoembolization in malignant lung tumors

Standard treatment options in patients with lung cancer and pulmonary metastases are surgery, radiotherapy, chemotherapy, and immunotherapy. For reducing clinical complications of surgery and achieving a better local response, transpulmonary chemoembolization of the lungs is a possible interventional technique in which anticancer drugs are administered directly into a tumor through its feeding vessels followed by occlusive agents that are injected through the delivery catheter for blocking the vessel. This allows a longer contact period in the tumor with a higher cytostatic drug concentration. The technique is safe and results present promising local response rates, but the influence on survival is still questionable. This article describes the current role of intravascular therapies in the treatment of pulmonary malignancies.

Unresectable lung malignancy: combination therapy with segmental pulmonary arterial chemoembolization with drug-eluting microspheres and radiofrequency ablation in 17 patients

PURPOSE

To evaluate the feasibility, safety, and effectiveness of combining segmental pulmonary arterial chemoembolization (SPACE) and percutaneous radiofrequency (RF) ablation in patients with unresectable lung neoplasms or patients with resectable neoplasms who refused surgery and to compare the local tumor progression (LTP) rate with that in previous studies of RF ablation alone.

MATERIALS AND METHODS

After institutional review board approval and informed consent, 17 patients with primary and metastatic lung cancer were enrolled in this prospective study. Between January 2008 and February 2011, 20 nodules (median diameter, 3.0 cm; range, 2.0-5.0 cm) were treated during 19 sessions. Antineoplastic agents loaded on 50-100-µm microspheres were selectively infused into specific pulmonary arteries. Percutaneous computed tomography (CT)-guided RF ablation of lung nodules was performed 48 hours after SPACE. Follow-up consisted of enhanced CT 48 hours after combination treatment was completed, after 30 days, and every 3 months thereafter. Fluorine 18 fluorodeoxyglucose positron emission tomography was performed 3 months after combination therapy and then every 6 months. The t test was used to compare groups.

RESULTS

Technical success was achieved in 100% of cases. Ventilation-lung single photon emission computed tomography showed a wide area without ventilation in the lung parenchyma treated with SPACE. The LTP rate was 21% (three of 14 nodules) in 3-5-cm-diameter tumors and 0% (zero of six nodules) in tumors of 3 cm or smaller in diameter. Complete response was achieved in 65% (11 of 17) of patients at minimum follow-up of 6 months. Overall, treatment was well tolerated. Major complications were pneumothorax in five of 19 sessions (26%) and one bronchopleural fistula (one of 19, 5%). No treatment-related changes in general lung function were noted.

CONCLUSION

Combination therapy with RF ablation after SPACE to treat unresectable lung tumors is technically feasible, safe, and effective and may represent an advantage over RF ablation alone.

Photodynamic therapy enhances liposomal doxorubicin distribution in tumors during isolated perfusion of rodent lungs

BACKGROUND

Photodynamic therapy (PDT) at low drug-light conditions can enhance the transport of intravenously injected macromolecular therapeutics through the tumor vasculature. Here we determined the impact of PDT on the distribution of liposomal doxorubicin (Liporubicin™) administered by isolated lung perfusion (ILP) in sarcomas grown on rodent lungs.

METHODS

A syngeneic methylcholanthrene-induced sarcoma cell line was implanted subpleurally in the left lung of Fischer rats. Treatment schemes consisted in ILP alone (400 μg of Liporubicin), low-dose (0.0625 mg/kg Visudyne®, 10 J/cm(2) and 35 mW/cm(2)) and high-dose left lung PDT (0.125 mg/kg Visudyne, 10 J/cm(2) and 35 mW/cm(2)) followed by ILP (400 μg of Liporubicin). The uptake and distribution of Liporubicin in tumor and lung tissues were determined by high-performance liquid chromatography and fluorescence microscopy in each group.

RESULTS

Low-dose PDT significantly improved the distribution of Liporubicin in tumors compared to high-dose PDT (p < 0.05) and ILP alone (p < 0.05). However, both PDT pretreatments did not result in a higher overall drug uptake in tumors or a higher tumor-to-lung drug ratio compared to ILP alone.

CONCLUSIONS

Intraoperative low-dose Visudyne-mediated PDT enhances liposomal doxorubicin distribution administered by ILP in sarcomas grown on rodent lungs which is predicted to improve tumor control by ILP.

Regional Lung Chemotherapy Techniques

Selective delivery of chemotherapy to an affected organ or region of the body promises improved drug efficacy for the targeted area while minimizing the systemic exposure and toxicity. Several intravascular surgical techniques to achieve targeted regional lung chemotherapy have been developed. Investigations have been carried out to determine the feasibility, safety, and efficacy of these techniques in the primary or adjuvant setting with the intent to palliate or cure. This overview describes the history, rationale, technical aspects, and clinical experience of four regional lung chemotherapy techniques delivered by vascular manipulations including bronchial artery infusion, pulmonary artery chemoembolization, isolated lung perfusion, and lung suffusion.

Locoregional therapy

Even after complete surgical resection of pulmonary metastases, many patients develop recurrent disease in the thorax despite the use of systemic chemotherapy, dosage of which is limited because of systemic toxicity. Although subsequent operations are feasible and good long-term results have been reported, sufficient functional lung parenchyma must remain. For this reason, new treatment strategies are explored. Similar to isolated limb and liver perfusion, isolated lung perfusion (ILuP) is a promising surgical technique for the delivery of high-dose chemotherapy with minimal systemic toxicity. The use of biologic response modifiers, such as tumor necrosis factor, is also feasible. ILuP with high-dose chemotherapy has proven to be highly effective in the experimental models of pulmonary metastases with a superior survival advantage compared with systemic treatment. Lung levels are significantly higher after ILuP compared with intravenous therapy without systemic exposure. Phase I human studies have shown that ILuP is technically feasible with low morbidity and without compromising the patient's pulmonary function. Further clinical studies are necessary to determine its definitive effect on local recurrence, long-term toxicity, pulmonary function, and survival.

Transpulmonary chemoembolization: a novel approach for the treatment of unresectable lung tumors

This article describes the technique of transpulmonary chemoembolization for the palliative treatment of unresectable lung tumors. Early utilization of this method has resulted in reduction in tumor volume and alleviation of patient symptoms. After superselective catheterization, cytotoxic agents are administered, and the pulmonary arterial supply of the tumor is occluded by injection of microspheres and ethiodized oil. Emerging data suggest that this approach is well tolerated.

Pharmacokinetics of isolated lung perfusion with melphalan for resectable pulmonary metastases, a phase I and extension trial

BACKGROUND

Isolated lung perfusion (ILuP) with melphalan was performed under normo- and hyperthermic conditions combined with pulmonary metastasectomy for patients with resectable lung metastases. We present the results of pharmacokinetic analysis of a phase I and extension trial.

METHODS

Twenty-one procedures of ILuP with melphalan were performed in the phase I trial according to a dose-escalation schedule under normothermic and hyperthermic conditions followed by surgical resection of pulmonary metastases. In an extension trial 8 additional procedures with 15 and 45 mg melphalan were performed under hyperthermic conditions. Samples of serum, perfusate, lung, and tumor tissue were obtained.

RESULTS

High perfusate concentrations of melphalan were recorded in contrast to low systemic concentrations. Marked interindividual variability was observed in melphalan concentrations in perfusate, tumor, and lung tissue. Statistically significant correlation between melphalan dose, and perfusate area under the concentration-time curve (R(2) = 0.578, P = 0.001) and lung tissue concentrations (R(2) = 0.459, P = 0.028) were noted. No significant correlation between melphalan dose and tumor tissue concentrations could be established.

CONCLUSION

Isolated lung perfusion effectively delivers high doses of melphalan to the lung and tumor tissues with minimal systemic levels. Significant correlation between perfused melphalan dose, perfusate area under the concentration-time curve and lung tissue melphalan concentrations were observed.

Surgical and Nonsurgical Therapy for Lung Metastasis: Indications and Outcomes

The management of pulmonary metastasis is a broad and multifaceted topic. Because of the filtration function and the favorable microenvironment of the lung, most malignancies cause pulmonary metastases. This article focuses on recent experience with secondary lung malignancies and their newer treatment options, indications, and technical aspects.

Antegrade Versus Retrograde Isolated Lung Perfusion: Doxorubicin Uptake and Distribution in a Sarcoma Model

BACKGROUND

Antegrade and retrograde doxorubicin-based isolated lung perfusions were compared in rodents bearing a sarcomatous tumor in the perfused lung. Inasmuch as these tumors derive their vascularization from the bronchial artery system, we hypothesized that retrograde isolated lung perfusion through the pulmonary vein might result in an improved tumor drug uptake.

METHODS

Single-pass antegrade (n = 9) and retrograde (n = 9) isolated left lung perfusions were performed with 100 microg of doxorubicin in Fischer rats 10 days after subpleural tumor cell injection. The perfusion, washout, and recirculation times were 20, 10, and 60 minutes, respectively, followed by harvesting of the lung. The doxorubicin concentration and compartmental distribution in the tumor and in normal parenchyma of each perfused lung were measured by high-pressure liquid chromatography (6 animals of each group) and fluorescence microscopy (3 animals of each group).

RESULTS

Doxorubicin concentration and pattern of doxorubicin-based fluorescence signaling were comparable for both perfusion techniques in normal lung tissue. Antegrade and retrograde isolated lung perfusion resulted in similar tumor drug uptake, which was lower than in normal lung parenchyma, and in weak and sporadic fluorescence signaling emerging from the tumor periphery and from blood vessels situated within the tumor tissue.

CONCLUSIONS

Retrograde isolated lung perfusion did not confer a better doxorubicin uptake in the tumor as compared with antegrade lung perfusion despite the fact that the tumor vascularization in this model is based on the bronchial artery circulation.

Modified approach of administering cytostatics to the lung: more efficient isolated lung perfusion

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.

Isolated lung perfusion for pulmonary metastases

Isolated lung perfusion is an experimental surgical technique evaluated for the delivery of high-dose chemotherapy to improve 5-year survival after pulmonary metastasectomy. Extensive experimental work in animal models has demonstrated superior pharmacokinetics and efficacy compared with systemic therapy. Phase I clinical trials of isolated lung perfusion found a maximum tolerated dose**** of TNF-alpha, doxorubicin, cisplatin, and melphalan, whereas the combination of isolated lung perfusion with a complete metastasectomy was feasible. The combination of isolated lung perfusion and regional lung perfusion techniques needs further investigation.

Cytostatic lung perfusion results in heterogeneous spatial regional blood flow and drug distribution: Evaluation of different cytostatic lung perfusion techniques in a porcine model

OBJECTIVES

Comparison of doxorubicin uptake, leakage and spatial regional blood flow, and drug distribution was made for antegrade, retrograde, combined antegrade and retrograde isolated lung perfusion, and pulmonary artery infusion by endovascular inflow occlusion (blood flow occlusion), as opposed to intravenous administration in a porcine model.

METHODS

White pigs underwent single-pass lung perfusion with doxorubicin (320 mug/mL), labeled 99mTc-microspheres, and Indian ink. Visual assessment of the ink distribution and perfusion scintigraphy of the perfused lung was performed. 99mTc activity and doxorubicin levels were measured by gamma counting and high-performance liquid chromatography on 15 tissue samples from each perfused lung at predetermined localizations.

RESULTS

Overall doxorubicin uptake in the perfused lung was significantly higher (P = .001) and the plasma concentration was significantly lower (P < .0001) after all isolated lung perfusion techniques, compared with intravenous administration, without differences between them. Pulmonary artery infusion (blood flow occlusion) showed an equally high doxorubicin uptake in the perfused lung but a higher systemic leakage than surgical isolated lung perfusion (P < .0001). The geometric coefficients of variation of the doxorubicin lung tissue levels were 175%, 279%, 226%, and 151% for antegrade, retrograde, combined antegrade and retrograde isolated lung perfusion, and pulmonary artery infusion by endovascular inflow occlusion (blood flow occlusion), respectively, compared with 51% for intravenous administration (P = .09). 99mTc activity measurements of the samples paralleled the doxorubicin level measurements, indicating a trend to a more heterogeneous spatial regional blood flow and drug distribution after isolated lung perfusion and blood flow occlusion compared with intravenous administration.

CONCLUSIONS

Cytostatic lung perfusion results in a high overall doxorubicin uptake, which is, however, heterogeneously distributed within the perfused lung.

Pharmacokinetics after Endovascular Lung Perfusion with Cisplatin

PURPOSE

Endovascular lung perfusion (ELP) is a technique designed to deliver high doses of cisplatin via the pulmonary artery for the treatment of lung tumors. The purpose of the current study was to evaluate variables that affect adduct formation.

MATERIALS AND METHODS

Thirteen swine underwent ELP. The first group (n = 6) underwent infusion of 150 mg cisplatin diluted to 0.5 mg/mL via a balloon occlusion catheter in the left pulmonary artery. Uptake was compared with that seen with systemic infusion. A second group (n = 7) underwent bilateral sequential infusion of the left pulmonary artery, followed by the right. Cisplatin (150 mg) was infused at one of three concentrations: 1 mg/mL (n = 5 lungs), 0.67 mg/mL (n = 5 lungs), or 0.5 mg/mL (n = 4 lungs). The Pearson coefficient was used to correlate uptake with infusion time, infusate concentration, animal weight, and initial mean pulmonary artery pressure.

RESULTS

In the first group, cisplatin uptake in the control lung was less than 8% of that in the study lung. Infusion times for both groups ranged from 3 minutes to 56 minutes. Increases in infusion time correlated with increased adduct levels (r = 0.831; P < .0001). Mean uptake at concentrations of 0.5, 0.67, and 1 mg/mL were 25.79, 12.43, and 13.12 fmol/mug, respectively. There was no significant correlation between pulmonary adduct levels and infusate concentration (r = 0.106; P = .72). Animal weight and initial mean pulmonary artery pressure were not correlated with adduct formation.

CONCLUSIONS

ELP with longer infusions of cisplatin may lead to greater adduct formation in pulmonary tissues. Changes in concentration of the infusate do not affect uptake of cisplatin. Hemodynamic parameters do not affect cisplatin uptake.

Isolated lung perfusion with melphalan: Pharmacokinetics and toxicity in a pig model

BACKGROUND

In patients with unresectable lung cancer or pulmonary metastases, isolated lung perfusion (ILP) has been described as an alternative method to deliver high-dose chemotherapy to the lungs, thereby minimizing systemic toxicity. Pharmacokinetics of ILP have not been extensively investigated. Therefore, we studied the feasibility of ILP with melphalan in a pig model with emphasis on pharmacokinetics and acute lung damage.

METHODS

Five pigs underwent ILP with melphalan. Blood and tissue samples were obtained for determination of melphalan levels. Tissue biopsies were taken for microscopic evaluation of lung damage.

RESULTS

During ILP, no hemodynamic effects of importance were noted. No systemic leakage of melphalan was observed in any of the animals. Compared with normal lung tissue, microscopic examination of lung tissue after perfusion without melphalan showed pulmonary edema. Directly after melphalan perfusion additional hemorrhagic areas were seen; however, electron microscopy displayed no irreversible endothelial damage.

CONCLUSION

This study on pigs proved to be a well reproducible model for ILP with melphalan. Pharmacokinetics show a safety profile with no systemic toxicity, which could justify further patient studies, necessary to determine its effect on pulmonary metastases in humans, especially in case of adjuvant therapy after surgical resection or in unresectable disease.

Evaluation of tumour vascularisation in two rat sarcoma models for studying isolated lung perfusion. Injection route determines the origin of tumour vessels

Isolated cytostatic lung perfusion (ILP) is an attractive technique allowing delivery of a high-dose of cytostatic agents to the lungs while limiting systemic toxicity. In developing a rat model of ILP, we have analysed the effect of the route of tumour cell injection on the source of tumour vessels. Pulmonary sarcomas were established by injecting a sarcoma cell suspension either by the intravenous (i.v.) route or directly into the lung parenchyma. Ink perfusion through either pulmonary artery (PA) or bronchial arteries (BA) was performed and the characteristics of the tumour deposits defined. i.v. and direct injection methods induced pulmonary sarcoma nodules, with similar histological features. The intraparenchymal injection of tumour cells resulted in more reliable and reproducible tumour growth and was associated with a longer survival of the animals. i.v. injected tumours developed a PA-derived vascular tree whereas directly injected tumours developed a BA-derived vasculature.

Isolated Lung Perfusion With Melphalan for Resectable Lung Metastases: A Phase I Clinical Trial

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.

Isolated lung perfusion for the treatment of pulmonary metastases current mini-review of work in progress

Surgical resection of lung metastases is a widely accepted procedure but long-term results are disappointing with a 5-year survival rate of approximately 40%. Pulmonary metastasectomy is only indicated when complete resection can be achieved. A better survival is reported in patients with a single metastasis or a disease-free survival of more than 3 years. Intravenous chemotherapy has no major impact on survival because high-dose therapy is limited by systemic side-effects. Isolated lung perfusion has the advantage of both selectively delivering an agent into the lung while diverting the venous effluent. This allows the drug to be given in a significantly higher dose compared to intravenous therapy, while drug levels in critical organs are kept low enough to avoid significant morbidity. Isolated lung perfusion has proven to be effective for the treatment of lung metastases in animal models while the procedure is technically safe in humans. However, the real clinical value and survival benefit remain to be determined in ongoing clinical trials.The aim of this paper was to update the literature on isolated lung perfusion for the treatment of lung metastases. Furthermore, some proposals are made in order to improve the ultimate prognosis of these patients.

A validated assay for measuring doxorubicin in biological fluids and tissues in an isolated lung perfusion model: matrix effect and heparin interference strongly influence doxorubicin measurements

Doxorubicin is an antineoplasic agent active against sarcoma pulmonary metastasis, but its clinical use is hampered by its myelotoxicity and its cumulative cardiotoxicity, when administered systemically. This limitation may be circumvented using the isolated lung perfusion (ILP) approach, wherein a therapeutic agent is infused locoregionally after vascular isolation of the lung. The influence of the mode of infusion (anterograde (AG): through the pulmonary artery (PA); retrograde (RG): through the pulmonary vein (PV)) on doxorubicin pharmacokinetics and lung distribution was unknown. Therefore, a simple, rapid and sensitive high-performance liquid chromatography method has been developed to quantify doxorubicin in four different biological matrices (infusion effluent, serum, tissues with low or high levels of doxorubicin). The related compound daunorubicin was used as internal standard (I.S.). Following a single-step protein precipitation of 500 microl samples with 250 microl acetone and 50 microl zinc sulfate 70% aqueous solution, the obtained supernatant was evaporated to dryness at 60 degrees C for exactly 45 min under a stream of nitrogen and the solid residue was solubilized in 200 microl of purified water. A 100 microl-volume was subjected to HPLC analysis onto a Nucleosil 100-5 microm C18 AB column equipped with a guard column (Nucleosil 100-5 microm C(6)H(5) (phenyl) end-capped) using a gradient elution of acetonitrile and 1-heptanesulfonic acid 0.2% pH 4: 15/85 at 0 min-->50/50 at 20 min-->100/0 at 22 min-->15/85 at 24 min-->15/85 at 26 min, delivered at 1 ml/min. The analytes were detected by fluorescence detection with excitation and emission wavelength set at 480 and 550 nm, respectively. The calibration curves were linear over the range of 2-1000 ng/ml for effluent and plasma matrices, and 0.1 microg/g-750 microg/g for tissues matrices. The method is precise with inter-day and intra-day relative standard deviation within 0.5 and 6.7% and accurate with inter-day and intra-day deviations between -5.4 and +7.7%. The in vitro stability in all matrices and in processed samples has been studied at -80 degrees C for 1 month, and at 4 degrees C for 48 h, respectively. During initial studies, heparin used as anticoagulant was found to profoundly influence the measurements of doxorubicin in effluents collected from animals under ILP. Moreover, the strong matrix effect observed with tissues samples indicate that it is mandatory to prepare doxorubicin calibration standard samples in biological matrices which would reflect at best the composition of samples to be analyzed. This method was successfully applied in animal studies for the analysis of effluent, serum and tissue samples collected from pigs and rats undergoing ILP.

Pharmacokinetics after pulmonary artery perfusion with gemcitabine

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.

Surgical treatment for pulmonary metastases

As the lungs are a filter for the entire circulation, they are a common site for metastatic disease. Although never proven by a prospective randomized trial, surgical resection is a widely accepted treatment for pulmonary metastases on the condition that a complete resection can be obtained. However, many patients will develop recurrent disease in the thorax despite the use of systemic chemotherapy, dosage of which is limited due to systemic toxicity. As isolated limb and liver perfusion, isolated lung perfusion is an attractive and promising surgical technique for the delivery of high-dose chemotherapy with minimal systemic toxicity. The use of biological response modifiers, like tumour necrosis factor, is also feasible. Isolated lung perfusion has proven to be highly effective in rat models of pulmonary metastases with a clear survival advantage. Lung levels are significantly higher after isolated lung perfusion compared to intravenous therapy without systemic exposure. Preliminary human studies have shown that isolated lung perfusion is technically feasible with low morbidity and without compromising the patient's pulmonary function. Further clinical research is necessary to determine its effect on pulmonary metastases in man, especially in case of unresectable disease or as adjuvant therapy after surgical resection.

Temporary unilateral microembolization of the lung-a new approach to regional chemotherapy for pulmonary metastases

BACKGROUND

Except in patients with resectable disease, treatment of pulmonary metastases is still disappointing. Regional chemotherapy may be a suitable method for delivering more effective doses to regionally confined tumors while minimizing systemic toxicity. We propose an unilateral chemoembolization of the lung applicable by endovascular method.

MATERIALS AND METHODS

An unilateral microembolization of the lung with degradable starch microspheres (DSM) alone (group 1) and combined with carboplatin (group 2) was performed on Sprague-Dawley rats (n = 12). Microcirculatory parameters were studied by in vivo videomicroscopy and radiological pattern on pulmonary angiogram.

RESULTS

After injection of DSM, mean embolization time in subpleural capillaries was 7.1 +/- 2.3 min, followed by a mean flow retardation of 14.3 +/- 4.6 min; 21.4 +/- 4.7 min after embolization, original flow of erythrocytes was observed demonstrating reperfusion and reversibility of microembolization. After reperfusion relative fluorescence measured in subpleural alveoli was 0.13 +/- 0.049 in group 1, 0.105 +/- 0.016 in group 2, and 0.11 +/- 0.036 in control group (NS). Alveolar septal diameter was 17.3 +/- 1.13 microm in group 1, 16.8 +/- 1.25 microm in group 2, and 16.6 +/- 1.08 microm in control group (NS), demonstrating neither altered permeability nor pulmonary edema. Pulmonary angiogram confirmed patency of the central pulmonary artery.

CONCLUSION

For the first time unilateral microembolization of the lung could be established in an experimental model. By injection of DSM, reversible embolization on arteriolar and capillary level could be demonstrated without occlusion of the main branches of the pulmonary arteries. Alveolar-capillary membrane disorder as symptom of early toxicity could not be detected even with additional application of carboplatin.

Single-pass isolated lung perfusion versus recirculating isolated lung perfusion with melphalan in a rat model

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.

Technique and results of hyperthermic (41 degrees C) isolated lung perfusion with high-doses of cisplatin for the treatment of surgically relapsing or unresectable lung sarcoma metastasis

OBJECTIVE

A technique of hyperthermic isolated lung perfusion (ILP) chemotherapy was developed.

METHODS

Since April 1999, four patients with unilateral (n=2) or bilateral (n=2) sarcoma metastasis confined to a lobe (n=2) or entire lung (n=2) entered into a pilot study of hyperthermic (41 degrees C) ILP with high doses of cisplatin (70 mg/m(2)). Eligibility included drug resistant metastasis and at least four previous surgical metastectomies. The ILP of the lung segments was carried out following metastectomy, for 20-40 min at a rate of 0.3-0.5 l/min, a mean perfusion pressure lower than the own mean pulmonary artery pressure, and an inflow temperature of 41 degrees C or higher. Before and following ILP, the isolated lung segments were flushed with normothermic saline (1 l). Flow was continuously maintained by a centrifugal pump.

RESULTS

All patients successfully completed 31.7+/-9 min perfusion time at 41.4+/-0.3 degrees C, and this time-point corresponded to the maximal platinum lung-uptake (93.8 ng/mg tissue). The total vascular isolation was confirmed by continuously low systemic cisplatin plasma levels. There was no systemic drug-related toxicity but all patients experienced transient pulmonary toxicity as non-cardiogenic edema of the treated lung segments. With a median follow-up of 12 months, three patients are alive and disease-free and one died from cerebral metastasis without autopsy evidence of local recurrence 13 months following ILP.

CONCLUSION

Hyperthermic perfusion chemotherapy can be done safely and effectively. It represents a new treatment modality and deserves further investigations for patients with advanced, drug resistant or surgically refractory, lung sarcoma metastasis. However, further studies are needed to limit the ILP-induced pulmonary toxicity.

Pharmacokinetics of paclitaxel administered by hyperthermic retrograde isolated lung perfusion techniques

OBJECTIVE

Although paclitaxel is widely used as a systemic agent for the treatment of solid tumors, limited information is available concerning administration of this taxane by regional techniques. The present study was undertaken to evaluate the pharmacokinetics and acute toxicity of paclitaxel administered by hyperthermic retrograde isolated lung perfusion techniques to ascertain its potential for the regional therapy of unresectable pulmonary neoplasms.

METHODS

Adult sheep underwent 90 minutes of retrograde isolated lung perfusion with escalating doses of paclitaxel and moderate hyperthermia using a protein-free, oxygenated extracorporeal circuit and a steady perfusion pressure of 14 to 16 mm Hg. An additional animal received paclitaxel by means of 1-hour central venous infusion. Paclitaxel concentrations in lung tissues, perfusates, and systemic circulation were determined by high-performance liquid chromotography techniques. Cytotoxicity of paclitaxel in cancer cells and in normal human bronchial epithelial cells was evaluated in vitro using 4, 5-dimethylthiazo-2-yl-25-dipagnyl tetrazolium bromide assays. Lung tissues were examined by hematoxylin-and-eosin techniques.

RESULTS

Paclitaxel concentrations (maximum concentration and area under the plasma concentration time curve) in perfused tissues increased with escalating perfusate doses. Uptake of drug into lung parenchyma appeared saturable at high paclitaxel exposure; a substantial pharmacokinetic advantage was observed. Paclitaxel concentrations in systemic circulation were undetectable or exceedingly low after perfusion. Histopathologic examination of lung tissues harvested 3 hours after completion of isolated lung perfusion revealed no immediate toxicity, even at a paclitaxel exposure 20-fold higher than that achievable after 1 hour of intravenous administration at the maximum tolerable dose in human subjects. Moderate hyperthermia enhanced paclitaxel-mediated cytotoxicity 5- to 100-fold in cultured cancer lines. No paclitaxel toxicity was observed in cultured normal human bronchial epithelial cells after exposure to paclitaxel under normothermic or hyperthermic conditions.

CONCLUSIONS

These data support further evaluation of paclitaxel administered by hyperthermic retrograde isolated lung perfusion techniques for the treatment of unresectable malignant pulmonary tumors.

The role of pulmonary metastasectomy in soft tissue sarcoma

Pulmonary metastases are common in patients with soft tissue sarcoma. The majority of patients who develop pulmonary metastases are asymptomatic and are diagnosed during routine follow-up visits. There is evidence to suggest that pulmonary metastasectomy is associated with improved overall survival but only in patients with complete surgical resection. There are several criterion to identify patients for resection. The majority of resectable patients have peripheral lesions that are amenable to wedge resection. There is little evidence to suggest that chemotherapy improves survival. Future research is needed to better identify patients for metastasectomy, to determine the role of minimally invasive procedures, and to develop better adjuvant therapy.

New and evolving treatment methods for pulmonary metastases

Treatment strategies other than surgery for pulmonary metastases are needed to improve disease-free and overall survival. Surgical attempts to solve a biologic problem by mechanical means. Alternative treatment may include induction or adjuvant chemotherapy, lung perfusion or regional drug delivery, biologic therapies (inhaled IL-2, biologic modifiers), and potentially, molecular or genetic therapy. Experimental radiofrequency ablation techniques are rarely applicable. Combinations of resection of macrometastases with treatment of occult micrometastases may be best in improving disease-free and overall survival.

Relationship between the concentration of CDDP in tumor and tumor size after isolated lung perfusion treatment experimental study on a solitary pulmonary sarcoma model in rats

BACKGROUND AND OBJECTIVES

Few investigations on the pharmacokinetics of isolated lung perfusion (ILP) regional chemotherapy in tumors have been conducted. The purpose of this study was to evaluate the pharmacokinetic character of ILP in tumor tissues. Materials and Methods A solitary tumor nodule model was established in Fisher 344 rats by inoculating 1.0 x 10(6) methylcholanthrene-induced sarcoma cells into the left lung. On 14-21 days after the inoculation of tumor cells, rats were randomized into groups subjected to 10, 20, 40 or 60 min ILP with cis-diamminedichloroplatinum (CDDP) at concentrations of 25, 50, or 100 microg/ml. Total platinum concentration in tumors was measured by a flameless atomic absorption spectrophotometer.

RESULTS

The average tumor weights and total platinum concentrations were not significantly different among the perfusion groups. We found, however, that the total platinum concentrations in tumor nodules were significantly correlated inversely with the tumor weight (total platinum concentration in tumor = 1.167 x 1/tumor wt; R(2) = 0.981; P < 0.001).

CONCLUSIONS

The concentration of total platinum in the tumor tissue was found to be dependent on the weight of the tumor in ILP. Higher concentrations of total platinum were expressed in smaller tumor nodules than larger ones, indicating that ILP may be more effective against small tumors than large ones. Therefore, we suggest that large tumor legions should be debulked before ILP in patients with an unresectable lung tumor.

Pharmacokinetic differences between rat tumour and lung tissues following isolated lung perfusion with cisplatin

Isolated lung perfusion has been performed for the treatment of unresectable lung tumours; however, the pharmacokinetics of this procedure remain unclear. This study was conducted to investigate the changes in antitumour drug concentrations in tumour and lung tissues after isolated lung perfusion, using different perfusion times and perfusate drug concentrations. Isolated left lungs were perfused for 20, 40 or 60 min with 25, 50 or 100 micrograms/ml of cisplatin after solitary lung tumour nodules were established in rats, and the total platinum concentrations in the perfused lung and tumour tissues were determined by flameless atomic absorption spectroscopy. The oedema in the perfused lung tissues was evaluated by histological examination and by the wet to dry weight ratios of the lungs. The total platinum concentration increased significantly with perfusion time and increasing perfusate cisplatin concentrations in the lung tissue, but it did not change in the tumour tissue. The wet to dry weight ratios of the lung tissues did not differ significantly among the perfusion groups. Oedema of the perfused lung tissue did not change significantly with the perfusion time or perfusate cisplatin concentration. The results of this study indicate the possibility that different pharmacokinetics exist between tumour and lung tissues following isolated lung perfusion with cisplatin, which could be used as a clinical guide for the selection of appropriate perfusion times and perfusate drug concentrations.

Pleural space perfusion with cisplatin in the multimodality treatment of malignant mesothelioma: a feasibility and pharmacokinetic study

INTRODUCTION

Malignant pleural mesothelioma is an ideal model for testing new locoregional multimodality approaches because of its aggressive local behavior.

METHODS

This study was planned to investigate the feasibility, safety, and pharmacokinetics of a multimodality therapy including an operation, pleural space perfusion (60 minutes) with cisplatin (100 mg/m2), hyperthermia (41. 5 degrees C), and postoperative radiotherapy (55 Gy to chest wall incisions). The effects of the extent of resection and perfusion temperature on cisplatin pharmacokinetics were evaluated. Ten patients with epithelial or mixed, stage I or II, malignant pleural mesothelioma underwent the following procedures: group A (3 patients), pleurectomy/decortication and normothermic pleural space antineoplastic perfusion; group B (3 patients), pleurectomy/decortication and hyperthermic perfusion; and group C (4 patients), pleuropneumonectomy and hyperthermic perfusion. Operations were selectively applied depending on tumor extent. Platinum levels were serially measured by atomic absorption in systemic blood, perfusate, lung, and endothoracic fascia.

RESULTS

The overall procedure was completed in every case, without any death or toxicity. No lung damage was demonstrated after treatment. Major complications included 1 wound infection and 1 diaphragmatic prosthesis displacement. The mean peak platinum plasma levels were reached within 45 to 60 minutes after perfusion was started. Systemic drug concentrations were greater after pleurectomy/decortication than after pleuropneumonectomy (P =.006). The local tissue/perfusate ratio of platinum concentrations tended to be higher after hyperthermic perfusion rather than normothermic perfusion.

CONCLUSION

This multimodality approach is feasible, pharmacokinetically advantageous, and safe enough to undergo further clinical investigations.

[An experimental study of local chemotherapy for metastatic lung tumor--isolated lung perfusion and pulmonary artery infusion]

PURPOSE

We evaluated the efficacy of local chemotherapy using isolated lung perfusion (ILP) and pulmonary artery infusion (PAI) in vivo to improve prognosis for patients with metastatic lung diseases.

MATERIAL AND METHODS

Male F344 rats were used. The left lung was isolated and chemotherapeutic agents were administrated to the isolated lung by the ILP or PAI technique. Agents used were cisplatin (CDDP) and fluorouracil (5-FU), and their levels in the perfused lung and serum were measured (renal levels were also measured in CDDP groups). The results were compared with those obtained following intravenous administration (i.v.). In the ILP group, the left pulmonary artery and vein were clamped during perfusion. The agents were infused from the pulmonary artery, and the perfusate was collected from the pulmonary venotomy site following flushing with saline before declamping. In the PAI group, the left pulmonary artery was clamped and perfused with 0.2 ml of the agents, pulmonary arterial flow was occluded for 20 minutes, and perfusate was not collected. Rats were sacrificed 5 minutes after declamping in both groups, and the perfused lung and blood (and also kidneys in the CDDP group) were collected for pharmacokinetic examination. Histological examination of the perfused lung was also performed.

RESULTS

In the ILP group treated with 1 mg of CDDP and PAI group treated with 0.1 mg of CDDP administration, the lung CDDP levels were significantly higher and the serum and renal CDDP levels were significantly lower than those in the IV group. In the ILP group treated with 150 mg of 5-FU and PAI group treated with 10 mg of 5-FU, the lung 5-FU levels were significantly higher than those in all IV groups and the serum 5-FU levels were lower than those in the IV group treated with 10 mg and 15 mg of 5-FU. The bronchopulmonary construction was histologically maintained in the perfused lung in each group.

CONCLUSION

We concluded that local chemotherapy using ILP or PAI could be a safe and effective choice of therapy, and this method may be clinically applicable.

Characterization of local inflammatory response in an isolated lung perfusion model

BACKGROUND

Current phase I trials of isolated lung perfusion for treatment of pulmonary metastases have an arbitrarily determined length of perfusion. Our objective was to examine the temporal course of the local and distant inflammatory response as a function of the length of perfusion (ischemia) and subsequent reperfusion in an equivalent animal model.

METHODS

Sixty male Fischer 344 rats were randomized into four groups (n = 15). Each group underwent left isolated lung perfusion with buffered Hespan for 10, 30, 60, or 90 minutes. Subsequently, two subgroups of five animals within each group were allowed to reperfuse for 1 or 3 hours, respectively. Non-perfused right lung was used as control. At each time point, lung specimens were assayed for TNF-alpha by ELISA and histologic sections were examined.

RESULTS

There was no significant difference between the left and right lung tissue levels of TNF-alpha at the termination of the ischemic period. However, on reperfusion, the left lung TNF-alpha levels increased significantly above the ischemia baseline in all groups, with a greater magnitude of rise in the groups with 60 and 90 minutes of preceding ischemia (12,757 +/- 1985 vs. 3524 +/- 494 pg/g, and 16,914 +/- 1657 vs. 6530 +/- 1104 pg/g, respectively; p < 0.05). There was no significant elevation in tissue levels of TNF-alpha in the right lung. Histologic changes consistent with early pulmonary edema were first detected at 12 hours following onset of reperfusion.

CONCLUSIONS

Reperfusion following prolonged pulmonary ischemia during isolated lung perfusion results in a significant elevation of local tissue levels of TNF-alpha and may render the perfused lung vulnerable to the adverse effects of the inflammatory cascade.