Related factors of three dimensional conformal radiation therapy induced radiation pneumonitis in patients with esophageal cancer

Objective To analyze the related factors of three dimensional conformal radiation therapy induced radiation pneumonitis in patients with esophageal cancer.Methods 217 patients with esophageal cancer receiving three dimensional conformal radiation therapy were divided into the radiation pneumonitis group and the non- radiation pneumonitis group according to the occurrence of radiation pneumonitis,and then the related factors were analyzed.Results Sixty-one patients( 28.1%) suffered from radiation pneumonitis and were divided into the radiation pneumonitis group,and 156( 71.9%) patients without radiation pneumonitis were divided into the non-radiation pneumonitis group.The incidence of radiation pneumonitis of the elderly group was 36.7%,significantly higher than 21.0% in the non-elderly group( P 0.05),and there were no significant differences between gender,age,histological type,clinical stage and tumor location,with /without chemotherapy,pulmonary complications,smoking,Vdose of V35,V40,V45 and gross tumor volume( GTV)( P 0.05),but significant differences exsit in Vdose of V5,V10,V13,V15,V20,V25,V30,lung mean dose( LMD) and lung volume( P 0.01) between the two groups.Conclusion The Vdose,LMD,and lung function should be considered in developing three dimensional conformal radiation therapy plan for esophageal cancer patients,in order to reduce the lung injuries and the incidence of radiation pneumonitis.