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.

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 100% (95% CI: ([100%; 100%]) with Cyberknife ( = 0.2839). 2-year PFS and 2-year OS rates were 52.7% (95% CI [39.9%;64.0%]) 54.1% (95% CI [36.8; 68.6%]) ( = 0.8582) and 65.1% (95% CI: [51.9%; 75.5%] 83.9% (95% CI: [67.5%; 92.4%] ( = 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 ( = 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.