One Versus Three Fractions of Stereotactic Body Radiation Therapy for Peripheral Stage I to II Non-Small Cell Lung Cancer: A Randomized, Multi-Institution, Phase 2 Trial

Purpose: Stereotactic body radiation therapy for early stage non-small cell lung cancer is a standard of care for medically inoperable patients. Our aim was to compare Common Terminology Criteria for Adverse Events thoracic grade 3 or higher adverse events (AEs) of 30 Gy in 1 fraction (arm 1) versus 60 Gy in 3 fractions (arm 2). Methods and Materials: This was a randomized multi-institutional, phase 2, 2-arm clinical trial. Medically inoperable patients with biopsy-proven peripheral T1/T2N0M0 non-small cell lung cancer were enrolled. Patients were randomized to arm 1 or arm 2 and stratified by performance status. The primary endpoint was Common Terminology Criteria for Adverse Events thoracic grade 3 or higher AEs. Secondary endpoints were local control (LC), progression-free survival (PFS), overall survival (OS), and quality of life. Results: Between September 2008 and April 2015, 98 patients were randomized. Median follow-up was 53.8 months. Ten patients were lost to follow-up, 1 in arm 1 and 9 in arm 2. Thoracic grade 3 AEs were experienced by 8 (16%) patients on arm 1 and 6 (12%) patients on arm 2. There were no grade 4 or 5 AEs. There were no differences in LC, PFS, or OS (P = .68, .86, and .94, respectively). Arm 1 reported better social functioning (P = .006) with less dyspnea (P = .016) in follow-up at 6 months. Conclusions: This randomized phase 2 study demonstrated that 30 Gy in 1 fraction was equivalent to 60 Gy in 3 fractions in terms of toxicity, LC, PFS, and OS. Quality of life measures of social functioning and dyspnea favored single-fraction SBRT.