Stereotactic Body Radiotherapy for Early-Stage Non–Small Cell Lung Cancer: When and Why Is It Appropriate Therapy?

Author's disclosures of potential conflicts of interest are found at the end of this article. L ung cancer, the second most frequently diagnosed malignancy for men and women in the United States, will account for an estimated 221,200 newly diagnosed cases and 158,040 deaths in 2015 (Siegel, Miller, & Jemal, 2015). The preferred treatment for early-stage non–small cell lung cancer (NSCLC), often defined as stage I or stage II, is surgi-The 5-year overall survival (OS) rate without treatment is 20%. The OS rate for total lobectomy is 30% to 50% for patients with stage II NSCLC and 60% to 70% for patients with stage I NSCLC (Guckenberger et al. 25% of patients with lung cancer do not have surgery, either by choice or because of their comorbidities (Ishi-kura, 2012). The treatment options then include surveillance, chemo-therapy, radiation therapy, or an ab-lative procedure. Surgical excision is considered the standard of care for patients with early if possible, is preferred over subtotal lobectomy (also called wedge resec-tion) due to the likelihood of disease recurrence (Fernando & Timmer-man, 2012; Kelsey & Salama, 2013). Studies have shown that sublobar re-section has a local recurrence that is three times higher than that of lobec-tomy (Senan et al., 2013). However, it is estimated that 20% to 40% of patients diagnosed with stage I or stage II NSCLC who do not have surgery, either by necessity or choice (Allibhai et al., 2013; Senan et al., 2013). The number of patients diagnosed with early-stage NSCLC is expected to rise, as low