Prostate contouring uncertainty in megavoltage computed tomography images acquired with a helical tomotherapy unit during image-guided radiation therapy
Prostate contouring uncertainty in megavoltage computed tomography images acquired with a helical tomotherapy unit during image-guided radiation therapy
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DOI：
10.1016/j.ijrobp.2006.01.049
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发表时间：
2006-06-01
影响因子：
7
通讯作者：
Van Dyk, Jake
中科院分区：
文献类型：
--
作者：
Song, William Y.;Chiu, Bernard;Van Dyk, Jake
目的：为了评估兆伏计算机断层扫描 (MVCT) 的图像引导能力，本文比较了用于放射治疗计划的千伏计算机断层扫描 (KVCT) 与通过螺旋断层放射治疗获得的 MVCT 的观察者间和观察者内轮廓不确定性。方法和材料：对 5 名前列腺癌患者进行了评估。每名患者均接受一项 KVCT 和一项 MVCT 研究，总共 10 项 CT 研究。对于观察者间变异性分析，四名放射肿瘤学家、一名物理学家和两名放射治疗师（总共七名观察者）在 10 项研究中绘制了前列腺和精囊 (SV) 的轮廓。通过要求所有观察者重复 1 名患者的 KVCT 和 MVCT 研究轮廓来评估观察者内部变异性。通过使用体积和径向距离对轮廓变化进行定量分析。结果：与 KVCT 相比，MVCT 中观察者间和观察者内轮廓不确定性更大。观察者一致在 MVCT 上分割较大的体积，其中平均前列腺和 SV 体积的比率分别为 1.1 和 1.2。平均而言（观察者间和观察者内），以标准差表示的局部描绘变异性 [Delta sigma = root(sigma(2)(MVCT) - sigma(2)(KVCT))]，从 KVCT 到 MVCT 增加了 0.32 cm。 结论：尽管 MVCT 在前列腺描绘方面不如 KVCT，但 MVCT 在前列腺放疗中的应用仍然有用。 (c) 2006 爱思唯尔公司
Purpose: To evaluate the image-guidance capabilities of megavoltage computed tomography (MVCT), this article compares the interobserver and intraobserver contouring uncertainty in kilovoltage computed tomography (KVCT) used for radiotherapy planning with MVCT acquired with helical tomotherapy.Methods and Materials: Five prostate-cancer patients were evaluated. Each patient underwent a KVCT and an MVCT study, a total of 10 CT studies. For interobserver variability analysis, four radiation oncologists, one physicist, and two radiation therapists (seven observers in total) contoured the prostate and seminal vesicles (SV) in the 10 studies. The intraobserver variability was assessed by asking all observers to repeat the contouring of 1 patient's KVCT and MVCT studies. Quantitative analysis of contour variations was performed by use of volumes and radial distances.Results: The interobserver and intraobserver contouring uncertainty was larger in MVCT compared with KVCT. Observers consistently segmented larger volumes on MVCT where the ratio of average prostate and SV volumes was 1.1 and 1.2, respectively. On average (interobserver and intraobserver), the local delineation variability, in terms of standard deviations [Delta sigma = root(sigma(2)(MVCT) - sigma(2)(KVCT))], increased by 0.32 cm from KVCT to MVCT.Conclusions: Although MVCT was inferior to KVCT for prostate delineation, the application of MVCT in prostate radiotherapy remains useful. (c) 2006 Elsevier Inc.