2156 - A Meta-Analysis of Daily vs. Nonconsecutive Fractionation Schedules for Stereotactic Body Radiation Therapy for Early-Stage Non-Small Cell Lung Cancer

M. J. Tjauw, A. Mitta, A. Jarrouj, and T. D. Malouff; University of Oklahoma Health Sciences Center, Oklahoma City, OK

Purpose/Objective(s): In the United States, lung cancer is the leading cause of cancer death. Between 2010 and 2016, the non-small cell lung cancer (NSCLC) 5-year overall survival rate was 26.5%. The National Comprehensive Cancer Network (NCCN) guidelines described the recommended management of NSCLC. Stereotactic body radiation therapy (SBRT) has emerged as the optimal treatment for nonoperative NSCLC with excellent 3-year local control of 90%. However, there exists uncertainty over the optimal fractionation schedule between daily and nonconsecutive fractionation schedules. Materials/

Methods: A meta-analysis was performed using relevant literature from PubMed to identify studies comparing daily and nonconsecutive fractionation schedules for SBRT on NSCLC patient populations. Odds ratios were calculated, and forest plots were constructed for the toxicities. Weighted averages were calculated for the median overall survival (OS).

The inclusion criteria to select eligible studies: (a) patients receiving SBRT for early-stage NSCLC dosages of 45-60 Gray over 3-8 fractions; (b) studies must include data pertaining to both daily and nonconsecutive fractionation schedules; (c) studies may be retrospective, single-institution, multi-institution, controlled studies, or meta-analyses; (d) studies conducted after 2000.

The exclusion criteria to remove eligible studies: (a) one-armed studies analyzing only one of daily or nonconsecutive; (b) studies not analyzing post-operative toxicities.
Results: Our systematic review identified 5 suitable papers, which analyzed 916 patients of which 439 received daily fractions and 477 received nonconsecutive fractions. Our analysis concluded the median overall survival for the daily fractionation block (32.93 months) was less than nonconsecutive fractionation block (37.77 months). Amongst toxicities, cough OR is 1.03 (95% CI: 0.24, 4.31; p = 0.49), dyspnea OR is 0.81 (95% CI: 0.08, 8.31; p = 0.47), chest wall pain OR is 0.9 (95% CI: 0.14, 5.66; p = 0.92)., pneumonitis OR is 0.15 (95% CI: 0.05, 0.46; p = 0.47), and general pulmonary toxicity ORs are 0.40 (95% CI: 0.14, 1.10; p = 0.20), 2.57 (95% CI: 0.46, 14.47; p = 0.14), and 2.42 (95% CI: 0.53, 10.99; p = 0.2) for Grades 1, 2, and 3-5, respectively. There was no significant difference in the likelihoods.
Conclusion: SBRT is an effective and well tolerated treatment for NSCLC. To our knowledge, this study of 916 patient is the first systemic review to determine the optimal fractionation schedule using existing studies. This meta-analysis provides evidence that there is no potential survival advantage associated with nonconsecutive fractionation, both daily and nonconsecutive schedules exhibit similar safety profiles in terms of post-operative toxicities. Clinicians should consider these findings when making decisions about the fractionation schedule for SBRT in early-stage NSCLC, emphasizing the need for a personalized approach that balances efficacy and safety considerations for individual patients.