Radiation-induced esophagitis in local advanced non-small cell lung cancer after three-dimensional conformal radiotherapy

Abstract

Objective To explore radiation-induced esophagitis and its related factors in the patients with local advanced non-small cell lung cancer （ NSCLC ） which were treated with three-dimensional conformal radiation therapy （3D-CRT）. Methods From January 2001 to December 2008, 203 patients who suffered from stageⅢNSCLC were achieved, including 163 males and 40 females, with a median age of 63 years old, while 79 cases were in stageⅢa and 124 in stageⅢb . The equivalent median dose of tumor was 62 Gy（ range of 50-78 Gy） . Among them, 74 cases were administered with radiotherapy alone, 45 with sequential radiotherapy and chemotherapy, 87 cases with concurrent radiochemotherapy. Radiation esophagitis was evaluated with RTOG standard. The dosimetric parameters was estimated from dose volume histogrma （ DVH ） . The clinical and dosimetric parameters of radiation esophagitis were evaluated by spearman correlatived univariate and Logistic multivariable analysis. Results After radiotherapy, out of 203 patients, 87 had acute radiation esophagitis（RE）, 47 in grade 1, 37 in grade 2, and 3 in grade 3 RE. According to spearman correlatived analysis, the correlatived factors included ages, chemotherapy, GTV, PTV, the mean doses of PTV and lung, the max and mean dose of esophagus, V40 , V45 ,V50 ,V55 ,V60 , length of esophagus（ total circumference） treated with 45 Gy （ LETT45 ） , and LETT50 （ r=-0. 162-0. 235,P〈0. 05）. All the 14 factors had good correlation with RE in univariate analysis. But for other factors,such as gender, site of tumor, smoking, T, N, clinical stage, equivalent dose of tumor, style＆amp;nbsp;of radiation, the mean dose of GTV, LETT55 and LETT60 , there were not correlation with ≥grade 2 RE with univariate analysis（r= -0. 106-0. 122, P〉0. 05）. There were 21 factors, such as gender, age, smoking, clinical stage, site of tumor, chemotherapy, GTV, PTV, mean dose of PTV and lung, max and mean dose of esophagus, V40 -V60 of esophagus, LETT45-60 , incorporated into multivariable analysis, only chemotherapy and V45 of esophagus were independent predicted factors（Wald=4. 626, 9.882, P〈0. 05）. Conclusions In local advanced NSCLC after 3D-CRT, chemotherapy （ especially concurrent radiochemotherapy） could increase radiation-induced esophagitis. The parameter of DVH could also be used to predict radiation-induced esophagitis, V45 of esophagus may be the most valuable predictor. Key words: Non-small cell lung cancer; Local advanced; Three dimensional conformal radiotherapy; Radiation-induced esophagitis