Radiation Oncology Dept, Clinique & Maternité Ste-Elisabeth, Place Louise Godin 15, 5000 - Namur, Belgium.
Radiat Oncol. 2013 Jun 26;8:154. doi: 10.1186/1748-717X-8-154.
Intensity modulated radiotherapy for head and neck cancer necessitates accurate definition of organs at risk (OAR) and clinical target volumes (CTV). This crucial step is time consuming and prone to inter- and intra-observer variations. Automatic segmentation by atlas deformable registration may help to reduce time and variations. We aim to test a new commercial atlas algorithm for automatic segmentation of OAR and CTV in both ideal and clinical conditions.
The updated Brainlab automatic head and neck atlas segmentation was tested on 20 patients: 10 cN0-stages (ideal population) and 10 unselected N-stages (clinical population). Following manual delineation of OAR and CTV, automatic segmentation of the same set of structures was performed and afterwards manually corrected. Dice Similarity Coefficient (DSC), Average Surface Distance (ASD) and Maximal Surface Distance (MSD) were calculated for "manual to automatic" and "manual to corrected" volumes comparisons.
In both groups, automatic segmentation saved about 40% of the corresponding manual segmentation time. This effect was more pronounced for OAR than for CTV. The edition of the automatically obtained contours significantly improved DSC, ASD and MSD. Large distortions of normal anatomy or lack of iodine contrast were the limiting factors.
The updated Brainlab atlas-based automatic segmentation tool for head and neck Cancer patients is timesaving but still necessitates review and corrections by an expert.
头颈部癌症的强度调制放疗需要准确定义危及器官（OAR）和临床靶区（CTV）。这一关键步骤既耗时又容易出现观察者间和观察者内的差异。基于图谱的变形配准的自动分割可能有助于减少时间和差异。我们旨在测试一种新的商业图谱算法，以在理想和临床条件下自动分割 OAR 和 CTV。
对 20 名患者（10 名 cN0 期（理想人群）和 10 名未选择的 N 期（临床人群））进行了更新的 Brainlab 自动头颈部图谱分割测试。在手动勾画 OAR 和 CTV 之后，对同一组结构进行了自动分割，然后进行手动校正。计算了“手动到自动”和“手动到校正”体积比较的 Dice 相似性系数（DSC）、平均表面距离（ASD）和最大表面距离（MSD）。
在两组中，自动分割都节省了约 40%的相应手动分割时间。OAR 的效果比 CTV 更明显。自动获得的轮廓的编辑显著提高了 DSC、ASD 和 MSD。正常解剖结构的大变形或缺乏碘对比是限制因素。
用于头颈部癌症患者的更新的基于 Brainlab 图谱的自动分割工具可以节省时间，但仍需要专家进行审查和校正。
