UNASSIGNED: A total of 236 patients treated with IMRT were retrospectively reviewed in two independent groups of lung cancer from January 2014 to August 2018. The primary endpoint was grade 2 or higher acute RP (RP2). Dose metrics were generated from the bilateral lung volume outside GTV (VdoseG) and PTV (VdoseP). The associations of RP2 with clinical variables, dose-volume parameters and mean lung dose (MLD) were analyzed by univariate and multivariate logistic regression. The power of discrimination among each predictor was assessed by employing the bootstrapped area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI), and the integrated discrimination improvement (IDI).
UNASSIGNED: Thirty-four (14.4%) out of 236 patients developed acute RP2 after the end of IMRT. The clinical parameters were identified as less important predictors for RP2 based on univariate and multivariate analysis. In both studied groups, the significance of association was more convincing in V20P, V30P, and MLDP (smaller Ps) than V5G and V5P. The largest bootstrapped AUC was identified for the V30P. We found a trend of better discriminating performance for the V20P and V30P, and MLDP than the V5G and V5P according to the higher values in AUC, IDI, and NRI analysis. To limit RP2 incidence less than 20%, the V30P cutoff was 14.5%.
UNASSIGNED: This study identified the intermediate dose-volume parameters V20P and V30P with better prediction performance for acute RP2 than low-dose metrics V5G and V5P. Among all studied predictors, the V30P had the best discriminating power, and should be considered as a supplement to the traditional dose constraints in lung cancer treated with IMRT.
■从2014年1月至2018年8月,在两个独立的肺癌组中,对总共236例接受IMRT治疗的患者进行了回顾性分析。主要终点为2级或更高的急性RP(RP2)。从GTV(VdoseG)和PTV(VdoseP)以外的双侧肺体积产生剂量度量。RP2与临床变量的关联,通过单因素和多因素logistic回归分析剂量-体积参数和平均肺剂量(MLD).通过使用受试者工作特征曲线(AUC)下的自举面积来评估每个预测因子之间的辨别能力,净重新分类改进(NRI),和综合歧视改进(IDI)。
■236例患者中有34例(14.4%)在IMRT结束后发展为急性RP2。基于单变量和多变量分析,临床参数被确定为RP2的不太重要的预测因子。在两个研究小组中,关联的意义在V20P中更具说服力,V30P,和MLDP(PS小于V5G和V5P)。对于V30P鉴定了最大的自举AUC。我们发现V20P和V30P具有更好的辨别性能的趋势,根据AUC的较高值,MLDP比V5G和V5P,IDI,和NRI分析。为了将RP2发生率限制在20%以下,V30P的临界值为14.5%。
■这项研究确定了中等剂量体积参数V20P和V30P,对急性RP2的预测性能优于低剂量指标V5G和V5P。在所有研究的预测因子中,V30P具有最好的辨别能力,应视为IMRT治疗肺癌的传统剂量限制的补充。