非小细胞肺癌三维适形放疗后急性放射性食管炎相关剂量学因素分析

Dosimetry analysis on radiation-induced acute esophagitis after three-dimensional conformal radiotherapy for non-small cell lung cancer

目的探讨非小细胞肺癌（NSCLC）三维适形放疗后放射性食管炎发生的相关因素，为NSCLC三维适形治疗计划的制定提供参考指标。方法收集2000年8月至2004年12月符合入组条件在本科接受三维适形放疗的NSCLC患者104例，其中鳞癌45例，腺癌20例，针吸活检或气管镜刷片找到癌细胞者33例，未获得病理确诊者6例。其中全程三维适形放疗者46例，58例前程先行传统常规放疗后程再行三维适形放疗。全组患者处方剂量范围60～78Gy，中位剂量66Gy。变量间的相关性分析采用Spearman相关性检验，组问比较采用，检验，Logistic方法进行多元回归分析。结果本组患者放射性食管炎的发生率为46．2％，其中1级32例占30．8％，2级15例占14．4％，3级1例占1．0％。相关性分析表明食管接受的最大剂量、食管接受的平均剂量、照射野内的食管体积、食管U40、V45，V50、V55、V60、LETT45、LETT50、LET55、LETT60与放射性食管炎的发生呈正相关，多因素分析显示食管接受的最大剂量是≥2级放射性食管炎发生的独立性影响因素。结论食管接受的最大剂量、平均剂量、照射野内食管体积、食管V40～V60、食管LETT45～LETT60与放射性食管炎的发生呈正相关，尤其食管接受的最大剂量对预测放射件食管炎发牛右一窄参考价值。

Objective To analyze the related factors with radiation-induced esophagitis after threedimensional conformal radiotherapy for non-small cell lung cancer （NSCLC）, in order to explore the predictors for optimizing the treatment planning of NSCLC. Methods From Aug 2000 to Dec 2004, 104 NSCLC patients received radiotherapy and were eligible for this study, 45 cases squamous cell carcinoma, 20 cases adenocarcinoma, 33 cases carrying with cancer cells by test and 6 case with no definitive pathologic feature. 46 patients were treated with three dimensional conformal radiotherapy（3DCRT） , the other 58 patients conventional radiotherapy （CRT） before later-course 3DCRT. All the patients received the prescribed dose between 60-78 Gy and the median dose 66 Gy. The correlation of the variables were evaluated by Spearman relationship analysis. The morbidity of radiation-induced esophagitis was analyzed by x^2 test. The multivariate effect on radiation-induced esophagitis was statistically processed by Logistic regression model. Results In 104 patients, the morbidity of radiation- induced esophagitis was 46.2% , including 32 cases at grade 1, 15 cases at grade 2, 1 case at grade 3. Univariate analysis showed the maximal and mean dose of esophagus, the volume of esophagus irradiated, the values of V40, V45, V50, V55, V60, LETT45, LETT50, LETT55, LETT60 for the esophagus were correlated with radiation-induced esophagitis. Logistic regression model showed that the maximum dose received by the esophagus was the independent factor of ≥2 grade radiation-induced esophagitis. Conclusions The maxmal dose of esophagus received might be the important factor of radiation-induced esophagitis.