Efficacy And Safety Of Stereotactic Body Radiation Therapy In The Management Of Oligopersistent Disease In Patients With Egfr Mutant Non-small Cell Lung Cancer During EGFR-TKIs Treatment

Objective:To evaluate the efficacy and safety of stereotactic body radiation therapy in the management of oligopersistent disease in patients with epidermal growth factor receptor(EGFR)mutant non-small cell lung cancer(NSCLC)during epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs)treatment.Methods:Patients with NSCLC who obtained an EGFR mutation and whose oligopersistent diseases(1 to 3 sites)after EGFR-TKIs treatment were eligible for SBRT,which hospitalized in department of oncology of the Second Affiliated Hospital of Nanchang University from May 2016 to February 2018 were enrolled.The clinical outcomes of patients whose oligopersistent disease were treated with additive SBRT and those treated with EGFR TKIs alone were compared.The primary outcome variable was progression-free survival(PFS).The secondary outcome variables included disease control rate and radiation toxicity.Tumor response was defined depend on RECIST Criteria v.1.1.Acute and late toxicities were scored through the RTOG evaluation criterion.The survival rates were evaluated by the Kaplan-Meier analysis.The differences were tested using the log-rank test between the two groups.Results:Of the 45 patients treated with EGFR TKIs whose oligopersistent diseases were eligible for SBRT,twenty(45%)patients were treated with additive SBRT,whereas other(55%)patients were treated with EGFR TKIs alone.The median(range)follow-up of 19.6(4.8–50.6)months,median PFS of all patients was 15.3 months.Significant difference was showed between the two groups regarding PFS,which the median PFS of patients treated with additive SBRT and patients treated with EGFR TKIs alone were 15.9,12.4,respectively(p = 0.002).The 1-year and 1.5-year disease control of all patients were 68.9%(31/45),28.9%(13/45),respectively,which 1-year disease control rate of patients treated with additive SBRT and patients treated with EGFR TKIs alone were 75%,56%,respectively(p = 0.025),and the 1.5-year disease control rate were 45%,16%,respectively(p = 0.018).One patient occurred grade 3 radiation pneumonia 3 months later,and 3 patients occurred grade 2 radiation pneumonia 3 months later.No other radiation toxic reactions over grade 2 were observed.Conclusion:SBRT for oligopersistent disease in patients with EGFR mutant NSCLC during EGFR-TKI treatment prolonged PFS and improved disease control rate with tolerable toxicity.