Dosimetric Analysis of Radiation-induced Gastric Bleeding
Dosimetric Analysis of Radiation-induced Gastric Bleeding
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DOI：
10.1016/j.ijrobp.2012.02.029
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发表时间：
2012-09-01
影响因子：
7
通讯作者：
Ten Haken, Randall K.
中科院分区：
文献类型：
--
作者：
Feng, Mary;Normolle, Daniel;Ten Haken, Randall K.
目的：放射性胃出血一直知之甚少。在这项研究中，我们描述了分割放射治疗后胃出血的剂量学预测因素。方法和材料：回顾139例连续接受三维适形放射治疗(3D-CRT)的肝内恶性肿瘤患者的记录。中位随访期为7.4个月。将莱曼正常组织并发症概率(NTCP)模型中发生3级胃出血的参数(经肝硬变校正后)与数据进行了拟合。结果：116例可评估患者中有16例(14%)在完成放疗后发生胃出血的中位时间为4.0个月(平均6.5个月；范围2.1-28.3个月)。将3D剂量分布的每一部分生物校正为相当于每天2-GY的剂量后，胃的中位剂量和平均最大剂量分别为61和63GY(范围为46-86GY)。调整了肝硬变参数的Lyman NTCP模型预测了胃出血。最佳的Lyman模型参数为n=0.10，m=0.21，TD50(正常)=56GY，TD50(肝硬变)=22GY。较低的n值与最大剂量的重要性相一致；对于肝硬变患者，较低的TD50值表明他们具有更高的敏感性。结论：本研究表明，Lyman NTCP模型对预测胃出血具有实用价值，而肝硬变的存在大大增加了这种风险。这些发现应该有助于设计未来涉及高剂量上腹部辐射的临床试验。(C)2012年爱思唯尔公司。
Purpose: Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy.Methods and Materials: The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of >= grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models.Results: Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n=0.10 and m=0.21 and with TD50 (normal) = 56 Gy and TD50 (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD50 value for the cirrhosis patients points out their greater sensitivity.Conclusions: This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation. (C) 2012 Elsevier Inc.