Analysis Of Related Factors Of Radiation-induced Lung Injury Caused By SBRT In Lung Tumors

Objective: To explore the related factors analysis of radiation-induced lung injury caused by stereotactic radiotherapy(SBRT)of lung tumors.Methods: The clinical data of 66 patients who underwent stereotactic radiotherapy for lung tumors from January2013 to December 2019 in the First Affiliated Hospital of Xinjiang Medical University were selected for retrospective analysis to clarify the incidence of radiation-induced lung injury.Eexplore the related factors of radiation-induced lung injury.The patients were followed up,and the short-term efficacy was evaluated according to RECIST1.1,and the local control rate(LC)and overall survival rate(OS)were followed up for 1 and 2 years.Results: All patients completed radiotherapy,and a total of 22 patients suffered radiation-induced lung injury(33.3%).Univariate analysis showed that smoking history,history of chronic obstructive pulmonary disease,history of diabetes,equivalent biological dose,lung V20,and PTV were risk factors for radiation-induced lung injury(P<0.05).Multivariate analysis showed that PTV and V20 were independent risk factors for radiation-induced lung injury(P<0.05).The best PTV value of ROC curve predicting radiation-induced lung injury is 33.945 cm3,the sensitivity is 72.72%,and the specificity is 86.41%.The best value of V20 predicting radiation-induced lung injury is 9.244%,the sensitivity is 81.84%,and the specificity is 88.57%.3-6 months after the end of radiotherapy,the DCR in the stage I NSCLC group was 83.33%(5/6);the effective rate in the metastatic tumor group was 76.67%(46/66).Follow-up until January 1,2021,a total of 5 patients were lost to follow-up,with a median follow-up of22.9(2.3-52.5)months.The LC of lung metastases at 1 and 2 years were 93.32% and83.64%,and the OS of lung metastases at 1 and 2 years were 87.69% and 62.30%,respectively.Conclusion: Diabetes history,chronic obstructive pulmonary disease,smoking history,effective biometric size,PTV and V20,etc.can be related to the occurrence of radiation lung injury related to stereotactic radiotherapy of lung tumors;among them,PTV and V20 are independent risk factors for radiation lung injury.Stereotactic radiotherapy for lung tumors is a relatively safe and effective treatment option.