The Clinical Efficacy And Safety Analysis Of Osimertinib Combined With Brain Radiation Therapy On Non-Small Cell Lung Cancer With Brain Metastases

Purpose:To evaluate the efficacy of the third generation EGFR-TKI Osimertinib combined with brain radiation therapy in the treatment of brain metastasis of non-small cell lung cancer patients with EGFR mutation,to observe the side effects of the combined therapy,and to explore the clinical value and feasibility of the combined therapy.Methods:62 patients with metastatic NSCLC,confirmed EGFR gene mutation,were divided into two groups.The patients in the combined treatment group were treated with Osimertinib and brain radiation therapy,while the patients in the single treatment group were only treated with Osimertinib.The imaging data of patients within 1 month before treatment were collected,and the imaging reexamination and follow-up were carried out every 2 months after treatment.RECIST 1.1 guideline was used to evaluate the efficacy.The safety of the patients was evaluated by the Toxicity grading evaluation standards promulgated by Common Terminology Criteria for Adverse Events Version 4.0(CTCAE,4.0),and the cognitive impairment was measured by Montreal Cognitive Assessment.Results:1.For the patients with brain metastatic NSCLC with positive EGFR mutation,the objective response rate of combination group was higher than that of Osimertinib group(72.97%vs 44.00%,P=0.022).In terms of disease control rate,there was no significant difference between the combined treatment group and the single treatment group(94.59%vs 84.00%,P=0.344).The therapeutic effect of Osimertinib combined with radiation therapy is better than that of Osimertinib alone.2.Compared with Osimertinib,the combination of brain radiation therapy and Osimertinib improved the progression-free survival of patients with brain metastatic NSCLC(12.05 VS 9.64,P=0.020).The median progression-free survival was 12.00 months(95%CI 11.28--12.72)in the combined treatment group and 10.00 months(95%CI 8.80--11.20)in the single treatment group.There was a significant difference between the two groups(12.00 vs 10,00,P=0.021).3.The median overall survival of the patients in the combined treatment group was 16.00 months,95%confidence interval(CI)was 14.01-17.99;the median overall survival of the patients in the single treatment group was 13.00 months,95%confidence interval(CI)was 11.04-14.96.There was a significant difference in median survival time between the two groups(16.00 vs 13.00,P=0.031).The combined therapy improved the median overall survival.4.Except for cognitive impairment,there was no significant difference in the incidence of other side effects between the two groups(P>0.05).There was no significant increase in the side effects of Osimertinib combined with brain radiation therapy.5.Cognitive impairment gradually appeared in the combined treatment group at 6 and 12 months after radiotherapy,and there was a statistically significant difference at baseline before treatment.6.The disease control rates of the combined treatment group and the single treatment group were more than 80%.Using Osimertinib alone for brain metastatic NSCLC patients with EGFR mutation was more effective.Conclusion:As the third generation EGFR-TKI,Osimertinib has a good effect on brain metastatic NSCLC.Brain radiation therapy combined with Osimertinib has some advantages in the control of brain metastasis,and improves the progression-free survival and median overall survival of patients.There is no significant difference in side effects between the two groups,However,combination treatment increased the incidence of hair loss and adverse reactions of cognitive dysfunction.