DOSIMETRIC EVALUATION OF AUTOMATIC SEGMENTATION FOR ADAPTIVE IMRT FOR HEAD-AND-NECK CANCER
DOSIMETRIC EVALUATION OF AUTOMATIC SEGMENTATION FOR ADAPTIVE IMRT FOR HEAD-AND-NECK CANCER
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DOI：
10.1016/j.ijrobp.2009.06.012
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发表时间：
2010-07-01
影响因子：
7
通讯作者：
Xia, Ping
中科院分区：
文献类型：
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作者：
Tsuji, Stuart Y.;Hwang, Andrew;Xia, Ping
目的：适应治疗期间解剖变化的适应性计划需要重复分割。本研究使用剂量终点来评估自动变形的轮廓。方法和材料：16 名头颈癌患者由于放疗期间的解剖变化而制定了适应性计划。使用基于强度的自由形式配准算法将初始计划计算机断层扫描 (CT) 的轮廓变形为治疗中期 CT，然后使用 Dice 相似系数和重叠指数与同一 CT 的手动绘制轮廓进行比较。自动轮廓用于创建新的自适应计划。根据手动轮廓的剂量测定结果和计划保形性对原始自适应计划和自动自适应计划进行比较。结果：手动和自动分割的体积相似；只有肿瘤总体积（GTV）有显着差异。自动计划实现了较低的 GTV 平均覆盖率：V95：98.6 +/- 1.9% 与 89.9 +/- 10.1% (p = 0.004) 和临床目标体积：V95：98.4 +/- 0.8% 与 89.8 +/- 6.2% (p < 0.001) 以及脊髓 1 cm(3) 的平均最大剂量较高39.9 +/- 3.7 Gy 与 42.8 +/- 5.4 Gy (p = 0.034)，但其余结构没有差异。结论：自动分割不足以替代医生绘制的体积，特别是对于 GTV。然而，当通过剂量测定终点进行评估时，它会生成足够准确的正常结构轮廓。 (C) 2010 爱思唯尔公司。
Purpose: Adaptive planning to accommodate anatomic changes during treatment requires repeat segmentation. This study uses dosimetric endpoints to assess automatically deformed contours.Methods and Materials: Sixteen patients with head-and-neck cancer had adaptive plans because of anatomic change during radiotherapy. Contours from the initial planning computed tomography (CT) were deformed to the mid-treatment CT using an intensity-based free-form registration algorithm then compared with the manually drawn contours for the same CT using the Dice similarity coefficient and an overlap index. The automatic contours were used to create new adaptive plans. The original and automatic adaptive plans were compared based on dosimetric outcomes of the manual contours and on plan conformality.Results: Volumes from the manual and automatic segmentation were similar; only the gross tumor volume (GTV) was significantly different. Automatic plans achieved lower mean coverage fir the GTV: V95: 98.6 +/- 1.9% vs. 89.9 +/- 10.1% (p = 0.004) and clinical target volume: V95: 98.4 +/- 0.8% vs. 89.8 +/- 6.2% (p < 0.001) and a higher mean maximum dose to 1 cm(3) of the spinal cord 39.9 +/- 3.7 Gy vs. 42.8 +/- 5.4 Gy (p = 0.034), but no difference for the remaining structures.Conclusions: Automatic segmentation is not robust enough to substitute for physician-drawn volumes, particularly for the GTV. However, it generates normal structure contours of sufficient accuracy when assessed by dosimetric end points. (C) 2010 Elsevier Inc.