Short-term Efficacy Of Radiotherapy For Stage ? Lung Adenocarcinoma After TKI Treatment For Local Progression

Objective:To analyze the short-term efficacy of radiotherapy in patients with stage III lung adenocarcinoma whose EGFR mutation is positive after TKI treatment,and to compare the effects of different mutation sites on radiotherapy,and to predict the therapeutic efficacy by using gene status,soas to provide a choice for the formulation of individualized treatment.Methods:Thirty-one cases of lung adenocarcinoma with positive EGFR mutation in stage III were treated in Xinjiang Tumor Hospital from 2011 to 2018.All patients received 50-60GY/25-30F/5-6W intensity-modulated radiotherapy for primary lung lesions and metastatic lymph nodes.CT examination was performed to evaluate the size of tumors before and after radiotherapy for 1 month,and the volume change of GTVat the beginning and during radiotherapy,and to observe the incidence of side effects.Further compareisons of Curative effects between 19 Del and 21 L858 R groups.Result:Among the 31 patients with positive EGFR mutation,there were 0 cases of CR,17 cases of PR,13 cases of SD and 1 case of PD,54.8% of ORR and 96.8% of DCR.The volumes of GTV1 and GTV2 were 86.58 ±92.51 and 66.42±70.58,respectively.The t-test of paired samples showed that the volumes of GTV2 were significantly smaller than those of GTV1,P< 0.05.The difference was statistically significant.The indexes of CYFRA21-1,CEA and Pro GRF in tumor-associated antigens after radiotherapy were lower than those before radiotherapy,P< 0.05,the difference was statistically significant.Acute toxicity and side effects were mainly in grade 1-2,and no grade 4 side effects occurred.Further analysis sh-owed that there were 12 cases of 19 Del,with curative effect of CR 0 cases,PR 6 cases,SD 5 cases,PD1 cases,ORR 50.0%,DCR 91.7%.There were 16 cases of 21 L858 R.The curative effect was CR0,PR9,SD7,PD0,ORR was 56.3%,DCR was 100%.There was no significant difference in ORR and DCR between the two groups(ORRp = 1.000,DCRp = 0.429).The difference of volume before and after GTV in 19 Del and 21 L858 R groups was 29.69 ±37.10 and 14.88±23.90,respectively,P > 0.05,with no significant difference.Conclusion:This study showed that radiotherapy for stage III pulmonary adenocarcinoma with EGFR mutation after EGFR-TKI treatment for local progress has a certain short-term clinical efficacy,and there is no difference between 19 Del and 21L858 R point mutation in objective remission rate and disease control rate.