A clinical observation of pulmonary function changes following three-dimensional conformal radiation therapy in patients of stage III phase with non-small cell lung cancer

Objective To explore the relationships among pulmonary function,DVH and acute radiation pneumonitis after three-dimensional conformal radiation treatment in patients of statge Ⅲ phase with non-small-cell lung cancer.Methods Pulmonary function tests were conducted on 83 unoperable patients(male 52,female 31,median age 64,KPS≥70)before and after three months radiotherapy respectively.After the 3 months of follow-up,radiation pneumonitis were graded and V20,V30 and MLD were derived from dose volume histogram(DVH).Results All patients were treated radiotherapy with irradiation dose of 45～50 Gy,Acute radiation pneumonitis occurred in 26 patients with 17 Grade Ⅰ,2 Grade Ⅱ,3 Grade Ⅲ and no Grade Ⅳ and Ⅴ pneumonitis appeared.There were no significant difference between the pre-irradiation and the three months after irradiation for FVC(P0.05).But there were significant signifcance between pre-irradiation and three months after irradiation for FEV1.0 and DLCO(P0.05)V20,V30 and MLD were observed in patient treated with higher radiation pneumonitis.Conclusion There are closely relationships among pulmonary function,DVH and radiation pneumonitis in patienta with non-small-cell lung cancer.