Effect Of Tumor Morphology And Location On The Morbidity And Grade Of Radiation-induced Lung Injury After Imrt For Non-small Cell Lung Cancer

Objective To explore the effects of non-small cell lung cancer(NSCLC) intensity-modulated radiotherapy(IMRT)on the morbidity and grade of different tumor morphology and location on radiation-induced lung injury(RILI),in order to analyze the influencing factors of RILI to provide a reference for the development of individualized IMRT programs.Methods Retrospective analysis of data from patients with non-small cell lung cancer who underwent radical IMRT from January 2013 to June 2016,and collected general patient data,dosimetric parameters of the lung:mean lung dose(MLD),normal lung received a volume ratio greater than a certain dose(5Gy,20Gy):V5,V20,evaded(5Gy,20Gy)lung dose absolute volume:AVS5,AVS20,collected data on whether or not to incorporate radiation pneumonitis and other information.The cases were grouped according to the collected general clinical data,divided into vertical strip group and horizontal strip group according to tumor morphology,divided into upper lung group and lower lung group according to tumor location,and gross tumor volume(GTV)and lung dosimetry parameters were grouped by median.Univariate analysis of the incidence of RILI under different grouping conditions by chi-square test;Using rank sum test to compare the distribution of severity of RILI;Multivariate analysis using binary logistic regression to determine valuable predictors of radioactive damage.Results The median follow-up time of 63 patients was 11 months(range,6-57 months),of which 39 patients had RILI(61.9%)and 14 patients had grade 1(22.2%),20 cases(31.7%)at level 2,4 cases(6.3%)at level 3,1 case(1.6%)at level 4,and 0 at level 5.Univariate analysis suggested that the incidence of RILI after IMRT in different parts of the tumor(?~2=8.75,P=0.003),gross type(?~2=5.42,P=0.002),GTV(?~2=9,09,P=0.003)?V5(?~2=3.91,P=0.084)?V20(?~2=6.23,P=0.013)?MLD(?~2=14.89,P<0.001)?AVS5(?~2=13.92,P<0.001)?AVS20(?~2=4.23,P=0.04)grouping was statistically significant,while tumor morphology,age,gender,smoking,pathological type was not statistically significant.Rank sum test suggested:the distribution of radioactive pneumonia after radiotherapy was statistically significant in terms of location(z=-2.668,P=0.007),morphology(z=-1.996,P=0.046),gross type(z=-2.16,P=0.031),V5(z=2.95,P=0.003)?AVS5(z=-3.14,P=0.002)?V20(z=3.68,P<0.001)?MLD(z=4.59,P<0.001).There was no significant difference in the distribution of radiation pneumonitis severity in terms of age,gender,smoking,pathological type and AVS20.Multivariate analysis suggested that tumor sites (OR=4.35,P=0.039)and AVS5(OR=0.098,P=0.002)were predictors of RILI.The probability of RILI in lower lung tumors was 4.35 times that of the upper lung;while AVS5 was a protective factor for RILI.Conclusions Tumor location,morphology,GTV,whole lung V5,V20,MLD,AVS5,AVS20,and general types were associated with the occurrence of RILI;tumor site and AVS5 were independent influencing factors of RILI.