Stereotactic body radiotherapy for stage I non-small cell lung cancer

Surgical resection for patients with stage I non-small cell lung cancer (NSCLC) produces high long-term survival rates, but many patients are ineligible for surgery because of medical comorbidity or other factors. Stereotactic body radiotherapy (SBRT) is the standard of care for patients with medically inoperable stage I NSCLC. Studies have reported local control rates with SBRT of about 95% when an adequate radiation dose is used. Lymph node failure averages less than 5%, while distant metastatic recurrence represents the most common site of failure. SBRT is generally safe and well tolerated even by patients with substantial pulmonary comorbidities. On average, lung function tests reveal little or no change from baseline, although individual patients may exhibit changes in pulmonary function after treatment. Most studies report pneumonitis rates of 0% to 5%. Ongoing clinical trials are investigating single-fraction SBRT and evaluating the maximal tolerated dose for centrally located tumors.