非小细胞肺癌同期放化疗后重度急性放射性肺炎的预测模型研究

目的 利用剂量体积直方图(DVH)参数建立Logistic剂量反应及Lyman-Kutcher-Burman正常组织并发症概率(LKB-NTCP)模型,并评估其对非小细胞肺癌同期放化疗后重度急性放射性肺炎(SARP)的预测价值。方法 搜集2006—2010年间行三维适形放疗同期化疗的147例非小细胞肺癌患者资料。按美国RTOG毒性评价标准定义超过3级的ARP为SARP。根据DVH剂量学信息建立Logistic剂量反应模型和LKB-NTCP模型。结果 SARP 发生率为9.5%(14/147)。Logistic剂量反应模型参数:常数b₀=－6.66、b₁=0.252,TD₅₀=26.43 Gy,γ₅₀=1.67;模型曲线在17 Gy以下相对平坦,17~18 Gy处变为陡峭,SARP风险增大。LKB-NTCP模型参数:体积效应因子n=0.87±0.40,曲线斜率倒数m=0.27±0.10,TD₅₀₍₁₎=(29.5±8.0) Gy;Logistic回归及ROC分析均发现此参数下计算出NTCP值对SARP有良好预测价值(P=0.013、0.019)。结论 NTCP值对SARP的预测价值优于简单剂量参数,2个模型曲线均提示最大限制剂量在约17 Gy。

Study on prediction models for severe acute radiation pneumonitis in patients with non-small cell lung cancer after concurrent chemoradiotherapy

Objective To establish the Logistic dose response model and Lyman-Kutcher-Burman (LKB)-normal tissue complication probability (NTCP) model using dose-volume histogram (DVH) parameters and to evaluate their predictive values for severe acute radiation pneumonitis (SARP) in patients with non-small cell lung cancer (NSCLC) after concurrent chemotherapy and three-dimensional conformal radiotherapy (3DCRT). Methods The clinical data of 147 NSCLC patients who were treated with concurrent chemotherapy and 3DCRT from 2006 to 2010 were collected. According to RTOG criteria, grade 3 or even severer acute radiation pneumonitis was defined as SARP. The Logistic dose response model and LKB-NTCP model were established according to DVH dosimetric information. Results The incidence of SARP was 9.5%(14/147). The best-fit parameter values for Logistic dose response model were shown as follows:constant b₀=－6.66;constant b₁=0.252;TD₅₀=26.43 Gy;γ₅₀=1.67. The fit curve was relatively flat when the maximum limit dose (MLD) was<17 Gy, and it became sharper when the MLD was 17－18 Gy, which implied that the risk of SARP increased. The best-fit parameter values for LKB-NTCP model were shown as follows:volume factor n= 0.87±0.40;slope factor m= 0.27±0.10;TD₅₀₍₁₎=(29.5±8.0) Gy. The Logistic regression analysis and receiver operating characteristic (ROC) analysis showed that the NTCP value calculated using the parameter values had a good predictive value for SARP (Logistic regression:P=0.013;area under the ROC curve:0.707,P=0.019). Conclusions The predictive value of NTCP for SARP is better than simple dose parameters. The two model curves suggest that MLD is above 17 Gy.