A narrative review on pulmonary metastases management by non-surgical local techniques: where do we stand?

Objective: To analyze the existent evidence regarding local non-surgical therapies of lung metastases in terms of prognostic outcomes, control of disease and safety of treatment. Background: The rationale of local therapies for pulmonary metastases is either to increase the patient’s chance of survival or cure the disease, depending on the origin and histology of the tumour. Metastasectomy still represents the preferred local treatment for lung metastases; however, due to the obvious drawbacks of almost any surgical intervention, many patients are not considered eligible for surgery. Methods: An extended search with a priori selection criteria was performed on the treatment of pulmonary metastases with stereotactic radiotherapy, percutaneous ablation via radiofrequency, microwaves, cryoablation (CRA) and chemoembolization. Two reviewers independently screened the titles and abstracts of all retrieved papers; the reference lists of eligible studies were checked with the aim to find further studies not identified by the initial search. After final selection, 52 original articles were included. Conclusions: A discrete number of minimally invasive non-surgical methods has been developed for tumor patients who are ineligible for surgical treatment. Among the available techniques, stereotactic radiotherapy and percutaneous ablation are currently the most commonly used local therapies. They have emerged as valid alternatives in case of surgical or medical inoperability, and may offer cancer patients the possibility for controlling unresectable pulmonary metastases with opportunities for improved survival.