A comparison of two modalities of stereotactic body radiation therapy for peripheral early-stage non-small cell lung cancer: results of a prospective French study

Abstract

Objectives: This prospective, observational, non-randomized multicentric study was conducted to compare efficiency and toxicity using different modalities of stereotactic body radiation therapy (SBRT) in early-stage peripheral non-small cell lung cancer (NSCLC). Methods: From 9 April to 11 December, 106 patients were treated according to the local equipment availability for peripheral NSCLC with SBRT: 68 by linear accelerator equipped for SBRT and 38 by Cyberknife®. Multivariate analysis and propensity score analysis using Inverse Probability Treatment Weighting (IPTW) were undertaken in an effort to adjust for potential bias due to non-randomization. Results: 2-year local control rates were 97.0% (95% CI: [90.6%; 99.4%]) with SBRT by Linac vs 100% (95% CI: ([100%; 100%]) with Cyberknife® (p = 0.2839). 2-year PFS and 2-year OS rates were 52.7% (95% CI [39.9%;64.0%]) versus 54.1% (95% CI [36.8; 68.6%]) (p = 0.8582) and 65.1% (95% CI: [51.9%; 75.5%] versus 83.9% (95% CI: [67.5%; 92.4%] (p = 0.0831) using Linac and Cyberknife® respectively. Multivariate regression analysis indicates no significant effect of SBRT treatment type on PFS or OS. Local relapse could not be modeled due to the small number of events (n = 2). Acute and late toxicity rates were not significantly different. After IPTW adjustment, results were unchanged. Conclusions: No difference in efficiency or toxicity was shown after SBRT of peripheral NSCLC treatment using Linac or Cyberknife®. Advances in knowledge: This is the first large prospective non-randomized study focusing on peripheral localized NSCLC comparing SBRT using an appropriately equipped linac with Cyberknife®. No significant difference in efficiency or toxicity was shown in this situation.