Department of Clinical Oncology, University Hospitals Bristol NHS Foundation Trust, Bristol Haematology and Oncology Centre, Bristol, UK.
University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
Clin Oncol (R Coll Radiol). 2020 Jan;32(1):13-25. doi: 10.1016/j.clon.2019.06.015. Epub 2019 Jul 10.
To quantify inter-observer variation between all the intracranial stereotactic radiosurgery (SRS) providers in England in delineating the target volumes of four brain tumour cases.
Twenty-two, cross-platform SRS providers in England were instructed during a national commissioning assessment to contour the gross tumour volume (GTV) of six brain metastases, one cavernous sinus meningioma, one vestibular schwannoma and one pituitary adenoma. An expert reference group provided feedback if submitted contours were considered to be outliers and those centres were instructed to resubmit their contours. All contours were analysed in Python. The target volume contour (observed volume; V), encompassing volume, 50% agreement volume (AV), 100% agreement volume (AV), concordance index (CCI) and discordance index (DCI) were calculated.
Twenty-one centres participated using five different treatment platforms (CyberKnife, Gamma Knife, Varian Linac, Elekta Linac, Tomotherapy) and seven different treatment planning systems (GammaPlan, iPlan, Multiplan, Pinnacle, Eclipse, CMS Focal). The greatest variability was observed in the smallest brain metastases (GTV5 AV 0.0 cm, CCI 0.28-0.84, DCI 0.00-0.70) and pituitary case (AV 1.1 cm, CCI 0.42-0.82, DCI 0.01-0.40). The greatest agreement was observed with the vestibular schwannoma (AV 2.8 cm, CCI 0.77-0.94, DCI 0.00-0.17). There were four resubmissions for the cavernous sinus meningioma and three resubmissions for the pituitary adenoma.
Inter-observer variability was most evident with the smallest brain metastases and pituitary case. Several additional outliers and one acceptable contour were suggested using the metric-based analysis of AV, CCI and DCI. Comparing contours using these metrics is an effective way to identify whether individual contours are similar to the 'true' target and to flag potentially significant deviations.
量化英国所有颅内立体定向放射外科（SRS）提供者在勾画 4 例脑肿瘤靶区体积方面的观察者间变异性。
在全国委托评估期间，指示 22 名跨平台 SRS 提供者勾画 6 个脑转移瘤、1 个海绵窦脑膜瘤、1 个前庭神经鞘瘤和 1 个垂体腺瘤的大体肿瘤体积（GTV）。如果提交的轮廓被认为是异常值，则由一个专家参考组提供反馈，并且这些中心被指示重新提交他们的轮廓。所有轮廓均在 Python 中进行分析。计算靶区轮廓（观察体积；V）、涵盖体积、50%一致性体积（AV）、100%一致性体积（AV）、一致性指数（CCI）和不一致性指数（DCI）。
使用 5 种不同的治疗平台（CyberKnife、Gamma Knife、Varian Linac、Elekta Linac、Tomotherapy）和 7 种不同的治疗计划系统（GammaPlan、iPlan、Multiplan、Pinnacle、Eclipse、CMS Focal），有 21 个中心参与了研究。在最小的脑转移瘤（GTV5 AV 0.0 cm、CCI 0.28-0.84、DCI 0.00-0.70）和垂体瘤（AV 1.1 cm、CCI 0.42-0.82、DCI 0.01-0.40）中观察到最大的变异性。在前庭神经鞘瘤（AV 2.8 cm、CCI 0.77-0.94、DCI 0.00-0.17）中观察到最大的一致性。对海绵窦脑膜瘤进行了 4 次重新提交，对垂体腺瘤进行了 3 次重新提交。
在最小的脑转移瘤和垂体瘤中，观察者间变异性最为明显。使用基于 AV、CCI 和 DCI 的度量分析，建议了另外 4 个异常值和 1 个可接受的轮廓。使用这些指标比较轮廓是一种有效的方法，可以确定个体轮廓是否与“真实”靶区相似，并标记可能存在的显著偏差。
