Long-Term Analysis of 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 is standard of care for inoperable early-stage non-small cell lung cancer. Here, we report the long-term outcomes of 30 Gy in 1 fraction (arm 1) versus 60 Gy in 3 fractions (arm 2).

METHODS AND MATERIALS: This was a multi-institutional randomized, phase 2, 2-arm clinical trial. Medically inoperable patients with peripheral clinical T1-T2/N0M0 disease were enrolled. All patients had biopsy-confirmed disease. Patients were stratified by performance status and randomized to arm 1 or arm 2. The primary endpoint was thoracic grade 3 or higher adverse events per the Common Terminology Criteria for Adverse Events. Secondary endpoints included freedom from local failure, freedom from distal failure, progression-free (PFS) and overall survival (OS).

RESULTS

Between September 2008 and April 2015, 98 patients were randomized. Median survival was 40.3 months. There were no new attributable adverse events within the additional follow-up period. There were no differences in time to local failure, time to distant failure, PFS, or OS (P = .14, .17, .98, and .78, respectively).

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, local failure, distant failure, PFS, and OS.