肺癌适形放疗后放射性肺损伤CT分级的危险因素研究

Risk factors for computed tomography grade of radiation-induced lung injury in lung cancer treated with three-dimensional conformal radiotherapy

目的探讨接受三维适形放疗（3DCRT）后影响严重放射性肺损伤CT分级的危险因素。方法回顾性分析89例3DCRT的肺癌患者临床资料和随访CT影像资料，统计各临床因素及剂量体积参数。观察放疗结束6～12个月的CT影像资料并根据CT影像资料对放射性肺损伤进行评定分级。分析≥3级严重放射性肺损伤的危险因素。统计采用SPSS15．0软件。结果89例患者放射性肺损伤CT分级情况：0级8例占9．0％，1级13例占14．6％，2级24例占27．0％，3级23例占25．8％，4级21例占23．6％。单因素分析显示同步化疗（CCT）、大体肿瘤体积（GTV）外放边界、患侧肺平均剂量、患侧肺的V15～V45差异有统计学意义。多因素Logistic回归分析显示：CCT、GTV外放边界和患侧肺‰是影响严重放射性肺损伤CT分级的独立危险因素。结论对接受3DCRT的肺癌患者，CCT、GTV外放边界和患侧肺‰是影响严重放射性肺损伤cT分级的临床和剂量学危险因素。

Objective To analyze the clinical and dosimetric risk factors for computed tomography （CT） grade of radiation-induced lung injury in lung cancer treated with three-dimensional conformal radiotherapy （3DCRT）. Methods Eighty-nine lung cancer patients treated with 3DCRT were enrolled and CT scan images in more than 6 months were retrospectively analyzed. Clinical and dosimetric parameters were reviewed. Radiation-induced lung injuries were classified into 5 grades on CT images. Grade 3 or worse were considered clinically significant. Statistical software SPSS 15.0 was used to analyze the clinical and dosimetric risk factors that influenced the CT grade of radiation-induced lung injury. Results Eight of 89 patients （9.0%） developed grade 0 of radiation-induced hmg injury, 13 developed grade 1（ 14. 6% ）, 24 developed grade 2 （27.0%）, 23 developed grade 3 （25.8%） and 21 developed grade 4 （23.6%）. Univariable analysis showed that concurrent chemotherapy （CCT）, GTV margin, involved ipsilateral lung mean lung dose（ IMLD）, the percent of involved ipsilateral lung receiving over 15, 20,25,30,35,40 and 45 Gy （ V15, V20, V25, V30, V35, V40, V45 ） were significantly associated with over grade 3 of radiation-induced lung injury . On multivariate logistic regression analysis, CCT, GTV margin and V20 of ipsilateral lung emerged as statistically significant risk factors of over grade 3 radiation-induced lung injuries CT images. Conclusions CCT, GTV margin and V20 of ipsilateral lung might be clinical and dosimetric risk factors associated with the severe CT grade of radiation-induced lung injury for lung cancer treated with 3DCRT.