Discrimination of solitary pulmonary nodules based on vascular supply patterns with First-Pass Dynamic CT

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.

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.