Eminowicz Gemma, McCormack Mary
University College Hospital, London, UK.
University College Hospital, London, UK.
Radiother Oncol. 2015 Dec;117(3):542-7. doi: 10.1016/j.radonc.2015.10.007. Epub 2015 Oct 20.
BACKGROUND/PURPOSE: Accurate target volume delineation is essential for radiotherapy delivery, yet significant intra and inter-observer variability is documented. We analysed the variation in cervical cancer clinical target volume (CTV) delineation.
MATERIALS/METHODS: All INTERLACE participating centres completed two RTQA outlining exercises. The Trial Management Group created a consensus outline. A separate STAPLE algorithm outline was created. Using these two outlines an optimised gold standard was generated. Volume, maximum distance from DICOM centre in all directions, and Jaccard Conformity Index (JCI) were calculated and compared for each centres' outlines. Anatomical areas included within CTV were recorded to detect systematic differences.
21 outlines were compared for case 1 and 22 for case 2. Volume ranged from 340 cc to 676 cc (case 1) and from 458 cc to 806 cc (case 2). A maximum 4 cm difference between outlines was observed in one direction. JCI ranged from 0.51 to 0.81 (case 1) and 0.57 to 0.81 (case 2). Variation in anatomical areas included in CTV exists between the two cases and between centres.
Significant inter-observer variation in cervical cancer delineation has been demonstrated. Ongoing efforts are needed to ensure inter-observer consistency through education, guidelines and multi-centre collaboration.
背景/目的：精确的靶区勾画对于放疗的实施至关重要，但已记录到显著的观察者内和观察者间差异。我们分析了宫颈癌临床靶区（CTV）勾画的差异。
材料/方法：所有参与INTERLACE研究的中心完成了两项放疗质量保证（RTQA）轮廓勾画练习。试验管理组制定了一个共识轮廓。创建了一个单独的STAPLE算法轮廓。利用这两个轮廓生成了一个优化的金标准。计算并比较了每个中心轮廓的体积、在所有方向上距DICOM中心的最大距离以及杰卡德一致性指数（JCI）。记录CTV内包含的解剖区域以检测系统差异。
病例1比较了21个轮廓，病例2比较了22个轮廓。体积范围为340立方厘米至676立方厘米（病例1）和458立方厘米至806立方厘米（病例2）。在一个方向上观察到轮廓之间最大相差4厘米。JCI范围为0.51至0.81（病例1）和0.57至0.81（病例2）。两个病例之间以及各中心之间CTV内包含的解剖区域存在差异。
已证明宫颈癌勾画存在显著的观察者间差异。需要持续努力，通过教育、指南和多中心合作来确保观察者间的一致性。
