Image-Guided Stereotactic Body Radiation Therapy for Early-Stage Non-Small Cell Lung Cancer

Patients with early-stage non-small cell lung cancer (NSCLC) who cannot undergo surgery because of their lung function, cardiac function, bleeding tendency, or other comorbid conditions or who refuse surgery should be considered for definitive radiation therapy. Conventional fractionated radiotherapy (60-66Gy in 1.8-or 2.0-Gy fractions) in these patients with stage I/II disease has resulted in 5-year local control rates of 30-50% and overall survival rates of 10-30% (1,2). Modern three-dimensional conformal radiotherapy (3D-CRT), however, may improve clinical outcome compared with two-dimensional radiotherapy (3). Several studies have reported a benefit from such a dose escalation, suggesting a dose-response relationship from the standpoint of both survival and local disease control in these patients (1,2,4,5). Because early-stage NSCLC is not inherently a systemic disease at the time of diagnosis and because local control is poor after conventional radiotherapy, research directed toward improving survival should put more emphasis on improving local tumor obliteration.