Toxicity analysis for esophagus in locally advanced non-small cell lung cancer(NSCLC) treatment using three dimensional conformal radiotherapy combined with concurrent chemotherapy

Abstract

Objective To investigate the radiation toxicity for esophagus in stage Ⅲ NSCLC treatment using three dimensional conformal radiotherapy (3D CRT) combined with concurrent chemotherapy,and to obtain the relevant factors that can be regareded as predictors to complications of esophagus.Methods From Sep 2006 to Dec 2008,52 patients with stage Ⅲ NSCLC received 3D CRT plus concutrent chemotherapy of navelbine + cisplatin (NP) with prescription of 60 Gy/30 fractions,and chemotherapy at 1 and 5 week.Univariate and multivariate analysis and ROC (receiver operating characteristic curves) were performed to assess the association of radiation-induced esophagitis and the correlated factors.Results Of all the patients,84.6%(44/52) developed radiation esophagitis including grade 1 for 16 patients,grade 2 for 12 patients and grade 3 for 16 patients,without grade 4 developed.The correlative factors coreprised of mean esophagus dose (MED),the LETT_(40),LETT_(45),LETT_(50),LETT_(55),LETT_(60),V_(40)、V_(45)、V_(50)、V_(55)、and V_(60) of esophagus according to Spearman correlative analysis,and all the 11 factors could predict radiation esophagitis according to univariate analysis (X~2=7.355-8.690,P 26%,21 of 31(67.7%) developed 2 or 3 grade radiation esophagitis,while for the patients with V_(55) ≤26%,only 7 of 21(33.3%) developed severe esophagitis.Conclusions 3D CRT combined with concurrent chemotherapy for patients with stage Ⅲ NSCLC may develop severe radiation esophagitis.Dosimetric parameters (MED,LETT_(40),LETT_(45),LETT_(50),LETT_(55),LETT_(60),V_(40)、V_(45)、V_(50)、V_(55)、and V_(60)) were important to predict the radiation-induced esophagitis.According to multivariate analysis,C_(55) may be the most valuable predictor.When the value of V_(55) excluded 26%,the probability of esophagitis of grade 2 and 3 may increase notably. Key words: Lung neoplasm; Conformal radiotherapy; Chemotherapy; Acute radiation esophagitis