Radiation Oncology Department, CHR Verviers East Belgium, Verviers, Belgium.
Radiation Oncology Department, Institut Bergonié, Bordeaux, France.
Int J Radiat Oncol Biol Phys. 2024 Jan 1;118(1):29-40. doi: 10.1016/j.ijrobp.2023.07.020. Epub 2023 Jul 26.
Clinical target volume (CTV) delineation for pelvic lymph nodes in prostate cancer is currently based on 3 consensus guidelines with some inherent discrepancies. To improve the reproducibility in nodal delineation, the Francophone Group of Urological Radiotherapy (Groupe Francophone de Radiothérapie Urologique [GFRU]) worked toward proposing an easily applicable, reproducible, and practice-validated contouring guideline for pelvic nodal CTV.
The nodal CTV data sets of a high-risk node-negative prostate cancer clinical case contoured by 86 radiation oncologists participating in a GFRU contouring workshop were analyzed. CTV volumes were defined before and after a structured presentation of literature data on lymphatic drainage pathways and patterns of nodal involvement and relapse, illustrated using a reference contour (CRef) defined by 3 GFRU experts. The consistency between the participants' contours and CRef was assessed quantitively by means of the Simultaneous Truth and Performance Level Estimation (STAPLE) method, the Dice coefficient, and the Hausdorff distance and qualitatively using a count map. These results combined with the literature review were thoroughly discussed among GFRU experts to reach a consensus.
From the 86 workshop participants, the volume of the STAPLE CTV was 591 cc compared with 502 cc for CRef. The Dice coefficient of the STAPLE CTV compared with the experts' CRef was 0.736 (±0.084) before and 0.823 (±0.070) after the workshop; the standard deviation decreased from 11.5% to 8.5% over the workshop. The Hausdorff distance of the STAPLE CTV compared with the CRef was 34.5 mm (±12.4) before the workshop and 21.8 mm (±9.3) after the workshop. Four areas of significant interobserver variability were identified, and a consensus was reached.
Using a robust methodology, our cooperative group proposed an easily applicable, reproducible, and practice-validated guideline for the delineation of the pelvic CTV in prostate cancer, useful for implementation in daily practice and clinical trials.
目前，前列腺癌盆腔淋巴结的临床靶区（CTV）勾画基于 3 项共识指南，但这些指南存在一些固有差异。为了提高淋巴结勾画的可重复性，法国泌尿放射治疗组（Groupe Francophone de Radiothérapie Urologique [GFRU]）致力于提出一种易于应用、可重复且经实践验证的盆腔淋巴结 CTV 勾画指南。
对参加 GFRU 勾画研讨会的 86 名放射肿瘤学家勾画的高危淋巴结阴性前列腺癌临床病例的淋巴结 CTV 数据集进行了分析。在对淋巴引流途径和淋巴结受累及复发模式的文献数据进行结构化介绍后，定义了 CTV 体积，并使用 3 名 GFRU 专家定义的参考轮廓（CRef）进行了说明。使用同时真实性和性能水平估计（Simultaneous Truth and Performance Level Estimation [STAPLE]）方法、Dice 系数和 Hausdorff 距离对参与者轮廓与 CRef 的一致性进行了定量评估，并使用计数图进行了定性评估。将这些结果与文献综述结合起来，由 GFRU 专家进行了深入讨论，以达成共识。
在 86 名研讨会参与者中，STAPLE CTV 的体积为 591cc，而 CRef 为 502cc。STAPLE CTV 与专家 CRef 的 Dice 系数分别为研讨会前的 0.736（±0.084）和研讨会后的 0.823（±0.070）；研讨会期间，标准差从 11.5%降至 8.5%。STAPLE CTV 与 CRef 的 Hausdorff 距离分别为研讨会前的 34.5mm（±12.4）和研讨会后的 21.8mm（±9.3）。确定了 4 个存在显著观察者间变异性的区域，并达成了共识。
使用稳健的方法，我们的合作组提出了一种易于应用、可重复且经实践验证的前列腺癌盆腔 CTV 勾画指南，有助于在日常实践和临床试验中实施。
