ROC曲线法评价不同指标预测NSCLC放疗后放射性肺炎与食管炎发生的价值

Evaluation Using Receiver-operating Characteristic Curve of thePredictive Value of Influencing Factors of Radiation Pneumonitis and Esophagitis in Non-small Cell Lung CancerPatients Treated with Three-dimensional Conformal Radiotherapy

目的:探讨非小细胞肺癌(NSCLC)三维适形放射治疗后放射性肺炎与食管炎发生的相关因素,进一步应用ROC曲线评价影响因素预测放射性肺炎与食管炎发生的价值。方法:收集2000年8月至2004年12月符合入组条件接受三维适形放疗的NSCLC患者104例,分析放射性肺炎与食管炎发生的影响因素,采用受试者工作特征(ROC)曲线分析评价其临床诊断性能。结果:患者放射性肺炎发生率为62.6%,≥2级放射性肺炎的发生率为38.3%,单因素分析显示肺内病变的PTV、双肺Dmean、V5、V10、V15、V20、V25、V30、V35及V40对放射性肺炎的发生均有显著性影响,Logistic分析显示双肺V35为影响放射性肺炎发生的独立性因素。ROC曲线分析显示双肺V35预测放射性肺炎的最佳界值为20.75%,敏感度为66.10%,特异性为81.00%;放射性食管炎的发生率为46.2%。单因素分析表明NSCLC病变的GTV、CTV、PTV、食管接受的最大剂量和平均剂量、照射野内的食管体积、食管V40、V45、V50、V55、V60、食管LETT45、LETT50、LETT55、LETT60均与放射性食管炎的发生有关,Logistic分析显示病变的GTV、PTV、食管V60是放射性食管炎发生的独立性影响因素,ROC曲线分析显示病变的GTV、PTV、食管V60预测放射性食管炎的最佳界值分别为124.58cm^3(敏感度为68.75%,特异性为57.15%)、325.50cm^3(敏感度为81.25%,特异性为42.86%)及12.5%(敏感度为81.30%,特异性为69.60%)。结论:双肺V/35和病变的GTV/、PTV、食管V60分别是放射性肺炎与食管炎发生的独立影响因素。

Objective： To explore the correlation of radiation-induced pneumonitis （ RIP ） and esophagitis （RIE） with dosimetric parameters in patients treated with three-dimensional conformal radiation therapy （ 3DCRT ） for non-small cell lung cancer （ NSCLC ）. Methods： From August 2000 to December 2004, data from 104 NSCLC patients treated with definitive 3D-CRT were collected. Logis- tical regression analyses were performed to test the association between RIP and the influencing factors. The clinical efficiency was ana- lyzed using the receiver-operating characteristic （ ROC ） curve based on the above analysis. Results： In the study group, the rate of RIP was 62.6%, and the rate of ~〉grade 2 was 38.3%. Univariate analysis showed that the lung mean dose and lung V5-V40 were important factors influencing RIE Multivariable analysis indicated that lung V35 was likely to be an independent factor. The optimal cutoff value for lung V35 was 20.75%, corresponding to a sensitivity of 66.10% and specificity of 81.00% in the ROC curve. Both the gross tumor volume （ GTV ） and planning target volume （ PTV ） of NSCLC, as well as esophagus V60 were also found to be independent parame- ters for predicting RIE. The optimal cutoff value for esophagus V60 was 12.50%, corresponding to a sensitivity of 81.30% and specifici- ty of 69.60% in the ROC curve. There was a significant difference between the areas under the ROC curve of esophagus V60 as well as the GTVs and PTVs of NSCLC （ P 〈 0.05 ）. Conclusion： Lung V35 as well as the GTV and PTV of NSCLC are likely to be independent factors in predicting RIE Esophagus V60 is likely to be an independent factor in predicting RIE, respectively.