Stereotactic body radiotherapy for early stage lung cancer: History and updated role.

Stereotactic Body Radiotherapy (SBRT) represents a consolidated treatment option for patients with medically inoperable early stage non-small cell lung cancer (NSCLC). The clinical evidence accumulated over the past decade supports its use as an alternative to surgery with comparable survival outcomes. Due to its limited toxicity, SBRT is also applicable to elderly patients with very poor baseline pulmonary function or other severe comorbidities. Recent comparative studies in operable patients raised the issue of the possible use of SBRT also for this subgroup, with quite promising results that still should be fully confirmed by prospective trials with long-term follow up. In early stage lung cancer, clinicians are now faced with a decision-making process that should take into account different factors. The need of pathological diagnosis and accurate nodal staging still represents a challenge, as well as the interpretation of radiological findings after SBRT, often confusing du to the difficulties in distinguishing between radiation-induced changes and local relapse. Aim of this review is to summarize and discuss the major studies on SBRT for early stage lung cancer, providing data on its efficacy and toxicity and discussing the still open issues on its role. Quality of life, pulmonary function and risk of secondary cancers are also discussed, as well as future perspectives and current research topics.