Sargos P, Charleux T, Haas R L, Michot A, Llacer C, Moureau-Zabotto L, Vogin G, Le Péchoux C, Verry C, Ducassou A, Delannes M, Mervoyer A, Wiazzane N, Thariat J, Sunyach M P, Benchalal M, Laredo J D, Kind M, Gillon P, Kantor G
Radiotherapy department, institut Bergonié, 33076 Bordeaux cedex, France.
Radiotherapy department, institut Bergonié, 33076 Bordeaux cedex, France.
Cancer Radiother. 2018 Apr;22(2):131-139. doi: 10.1016/j.canrad.2017.09.004. Epub 2018 Mar 12.
The purpose of this study was to evaluate, during a national workshop, the inter-observer variability in target volume delineation for primary extremity soft tissue sarcoma radiation therapy.
Six expert sarcoma radiation oncologists (members of French Sarcoma Group) received two extremity soft tissue sarcoma radiation therapy cases 1: one preoperative and one postoperative. They were distributed with instructions for contouring gross tumour volume or reconstructed gross tumour volume, clinical target volume and to propose a planning target volume. The preoperative radiation therapy case was a patient with a grade 1 extraskeletal myxoid chondrosarcoma of the thigh. The postoperative case was a patient with a grade 3 pleomorphic undifferentiated sarcoma of the thigh. Contour agreement analysis was performed using kappa statistics.
For the preoperative case, contouring agreement regarding GTV, gross tumour volume GTV, clinical target volume and planning target volume were substantial (kappa between 0.68 and 0.77). In the postoperative case, the agreement was only fair for reconstructed gross tumour volume (kappa: 0.38) but moderate for clinical target volume and planning target volume (kappa: 0.42). During the workshop discussion, consensus was reached on most of the contour divergences especially clinical target volume longitudinal extension. The determination of a limited cutaneous cover was also discussed.
Accurate delineation of target volume appears to be a crucial element to ensure multicenter clinical trial quality assessment, reproducibility and homogeneity in delivering RT. radiation therapy RT. Quality assessment process should be proposed in this setting. We have shown in our study that preoperative radiation therapy of extremity soft tissue sarcoma has less inter-observer contouring variability.
本研究的目的是在一次全国性研讨会上评估原发性肢体软组织肉瘤放射治疗中靶区勾画的观察者间变异性。
六位肉瘤放射肿瘤学专家（法国肉瘤研究组成员）收到了两例肢体软组织肉瘤放射治疗病例：一例术前病例和一例术后病例。他们收到了勾画大体肿瘤体积或重建大体肿瘤体积、临床靶区体积并提出计划靶区体积的指导说明。术前放射治疗病例是一名大腿部1级骨外黏液样软骨肉瘤患者。术后病例是一名大腿部3级多形性未分化肉瘤患者。使用kappa统计进行轮廓一致性分析。
对于术前病例，在大体肿瘤体积（GTV）、临床靶区体积和计划靶区体积的勾画一致性方面表现为实质性（kappa值在0.68至0.77之间）。在术后病例中，重建大体肿瘤体积的一致性仅为一般（kappa：0.38），但临床靶区体积和计划靶区体积的一致性为中等（kappa：0.42）。在研讨会讨论期间，就大多数轮廓差异，尤其是临床靶区体积的纵向延伸达成了共识。还讨论了有限皮肤覆盖范围的确定。
准确勾画靶区体积似乎是确保多中心临床试验质量评估、放疗实施的可重复性和同质性的关键因素。在这种情况下应提出放疗质量评估流程。我们的研究表明，肢体软组织肉瘤的术前放射治疗观察者间轮廓变异性较小。
