Preoperative evaluation and indications for pulmonary metastasectomy

Pulmonary metastasectomy (PM) is an established treatment that can provide improved long-term survival for patients with metastatic tumor(s) in the lung. In the current era, where treatment options other than PM such as stereotactic body radiation therapy (SBRT), immunotherapy, and molecular-targeted therapy are available, thoracic surgeons should review the approach to the preoperative evaluation and the indications. Preoperative evaluation consists of history and physical examinations, physiological tests, and radiological examinations. Radiological examinations serve to identify the differential diagnosis of the pulmonary nodules, evaluate their precise number, location, and features, and search for extra thoracic metastases. The indication of PM should be considered from both physiological and oncological points of view. The general criteria for PM are as follows; (I) the patient has a good general condition, (II) the primary malignancy is controlled, (III) there is no other extrapulmonary metastases, and (IV) the pulmonary lesion(s) are thought to be completely resectable. In addition to the general eligibility criteria of PM, prognostic factors of each tumor type should be considered when deciding the indication for PM. When patients have multiple poor prognostic factors and/or a short disease-free interval (DFI), thoracic surgeons should not hesitate to observe the patient for a certain period before deciding on the indication for PM. A multidisciplinary discussion is needed in order to decide the indication for PM.