Incidence of late rectal bleeding in high-dose conformal radiotherapy of prostate cancer using equivalent uniform dose-based and dose-volume-based normal tissue complication probability models
Incidence of late rectal bleeding in high-dose conformal radiotherapy of prostate cancer using equivalent uniform dose-based and dose-volume-based normal tissue complication probability models
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DOI：
10.1016/j.ijrobp.2006.10.014
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发表时间：
2007-03-15
影响因子：
7
通讯作者：
Alber, Markus
中科院分区：
文献类型：
--
作者：
Soehn, Matthias;Yan, Di;Alber, Markus
目的：基于剂量-体积直方图（DVH）数据的直肠并发症的精确建模是允许前列腺癌放射治疗安全剂量递增的必要条件。我们将不同的基于等效均匀剂量（EUD）和基于剂量体积的正常组织并发症概率（NTCP）模型应用于319例前列腺癌患者的直肠壁DVH和随访数据，以确定最能预测≥ 2级直肠出血的剂量学因素。本研究使用了在William博蒙医院根据自适应放疗方案接受三维适形放疗（3D-CRT）的319例患者的数据。考虑了以下模型：（1）莱曼模型和（2）DVH简化为广义EUD的logit公式，（3）系列重建单位（RU）模型，（4）Poisson-EUD模型，以及（5）平均剂量-和（6）截止剂量-逻辑回归模型。参数及其置信区间采用最大似然estimation.Results：的患者，51（16.0%）显示2级或更高的出血。作为定性和定量评估，莱曼和Logit-FUD，串行RU，和泊松EUD模型拟合数据非常好。直肠壁平均剂量与2级或以上出血无关。在截止剂量模型中，接受量> 73.7戈伊与出血的相关性最显著。然而，这个模型拟合的数据更差比EUD为基础的models.Conclusions：我们的研究清楚地证实了晚期直肠出血的体积效应。这可以通过EUD类模型很好地描述，其中串联RU-和Poisson-EUD模型可以仅用两个参数来描述数据。基于剂量体积的截止剂量模型表现较差。(c)2007爱思唯尔公司
Purpose: Accurate modeling of rectal complications based on dose-volume histogram (DVH) data are necessary to allow safe dose escalation in radiotherapy of prostate cancer. We applied different equivalent uniform dose (EUD)-based and dose-volume-based normal tissue complication probability (NTCP) models to rectal wall DVHs and follow-up data for 319 prostate cancer patients to identify the dosimetric factors most predictive for Grade >= 2 rectal bleeding.Methods and Materials: Data for 319 patients treated at the William Beaumont Hospital with three-dimensional conformal radiotherapy (3D-CRT) under an adaptive radiotherapy protocol were used for this study. The following models were considered: (1) Lyman model and (2) logit-formula with DVH reduced to generalized EUD, (3) serial reconstruction unit (RU) model, (4) Poisson-EUD model, and (5) mean dose- and (6) cutoff dose-logistic regression model. The parameters and their confidence intervals were determined using maximum likelihood estimation.Results: Of the patients, 51 (16.0%) showed Grade 2 or higher bleeding. As assessed qualitatively and quantitatively, the Lyman- and Logit-FUD, serial RU, and Poisson-EUD model fitted the data very well. Rectal wall mean dose did not correlate to Grade 2 or higher bleeding. For the cutoff dose model, the volume receiving > 73.7 Gy showed most significant correlation to bleeding. However, this model fitted the data more poorly than the EUD-based models.Conclusions: Our study clearly confirms a volume effect for late rectal bleeding. This can be described very well by the EUD-like models, of which the serial RU- and Poisson-EUD model can describe the data with only two parameters. Dose-volume- based cutoff-dose models performed worse. (c) 2007 Elsevier Inc.