Radiographic response and clinical toxicity following SBRT for stage I lung cancer

Clinical outcomes following stereotactic body radiation therapy (SBRT) for stage I non-small cell lung cancer (NSCLC) are excellent, with local control rates ranging from 80% to 95% in medically inoperable patients. Toxicity following SBRT has been lower than expected, with exception for grade 3 to 5 events occurring in patients treated with high doses to mediastinal structures. In considering a randomized head-to-head comparison of SBRT versus surgery for stage I lung cancer, the interpretation of clinical response based on imaging is of great importance. This is because of the opportunity to salvage SBRT local failure with surgery in operable patients. The current literature is reviewed with respect to computed tomography (CT) and positron emission tomography (PET) with respect to response following SBRT. The reported toxicities following SBRT for both peripheral and central lung cancers are also reviewed.