A millimeter miss is as good as a thousand miles: The role of accurate target localization in lung stereotactic body radiation therapy

Surgical intervention with lobectomy and mediastinal lymph node dissection is considered the treatment of choice in early stage non-small cell lung cancer (NSCLC) (1). However, approximately 20-25% of patients with early stage NSCLC are poor surgical candidates for lobectomy because of concomitant severe cardiac or pulmonary co-morbidities. For these patients, conventional radiotherapy with 60 to 70 Gy delivered in 30-35 fractions over a 6-7-week period generally resulted in poor 20-40% 3-year and 10-30% 5-year survival rates (2,3). This inadequate tumor control is mainly due to the insufficient tumor dose that is limited by normal tissue toxicity and possible target-miss caused by tumor mobility.