Systemic review of the patterns of failure following stereotactic body radiation therapy in early-stage non-small-cell lung cancer: Clinical implications

PurposeTo analyze the patterns of failure, the toxicity profile, and the factors influencing efficacy of stereotactic body radiation (SBRT) for early-stage non-small-cell lung cancer (NSCLC).Methods and materialsA search was based on PubMed electronic databases. All searches were conducted in May, 2009.ResultsThe local control ranged from 80% to 100% in most studies with adequate isocentric or peripheral biologically effective dose (BED). Recurrences were associated with increased tumor size. The main pattern of failure after SBRT was distant metastasis. Grades 3–5 toxicity occurred mostly in centrally located tumors, and adjuvant chemotherapy may further decrease all recurrences; possibly translating to a survival benefit in large or centrally located tumors where high BED cannot be safely reached.ConclusionSBRT is an excellent treatment option for early-stage, and mostly medically inoperable, NSCLC. BED at both the isocenter and the tumor periphery is very important for optimal tumor control; higher doses are required for large (⩾T2) lesions; SBRT for centrally located tumors can be feasible with a much less aggressive dose regimen than 60–66 Gy/3 fractions and adjacent critical structures excluded from the target volume; chemotherapy may optimize the clinical outcome in large or centrally located lesions.