SBRT is very effective for stage I NSCLC. Biologically effective doses (BED) >100 Gy are recommended. Elderly patients and those with a limited performance status may not tolerate these high doses. This study investigated the outcomes after lower dose SBRT (BED < 90 Gy) in 46 patients with stage I NSCLC, who were aged ≥70 years or in reduced general condition. Local control rates at 1, 2, and 3 years were 100, 95, and 95 %, respectively. Rates of freedom from distant progression were 83, 63, and 54 %, and survival rates were 77, 57, and 36 %, respectively. Seventeen patients died during the follow-up, 11 (65 %) from distant progression of NSCLC, and six (35 %) from non-malignant causes. No patient developed radiation-induced pneumonitis. Thus, SBRT with BED <90 Gy resulted in excellent local control and appears to be a reasonable option for stage I NSCLC in elderly patients and those with a poor performance status.
Keywords: Biologically effective dose; Early stage; Non-small-cell lung cancer; Stereotactic body radiotherapy; Treatment results.