Department of Medical Physics, James Cook University Hospital, South Tees NHS Trust, Middlesbrough, United Kingdom.
Leeds Cancer Centre, St. James's University Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
Br J Radiol. 2020 Jun;93(1110):20190897. doi: 10.1259/bjr.20190897. Epub 2020 Apr 1.
Assessment of the extent of variation in delineations and dose optimisation performed at multiple UK centres as a result of interobserver variation and protocol differences.
CT/MR images of 2 cervical cancer patients previously treated with external beam radiotherapy (EBRT) and Brachytherapy were distributed to 11 UK centres. Centres delineated structures and produced treatment plans following their local protocol. Organ at risk delineations were assessed dosimetrically through application of the original treatment plan and target volume delineations were assessed in terms of variation in absolute volume and length, width and height. Treatment plan variation was assessed across all centres and across centres that followed EMBRACE II. Treatment plans were assessed using total EQD delivered and were compared to EMBRACE II dose aims. Variation in combined intracavitary/interstitial brachytherapy treatments was also assessed.
Brachytherapy target volume delineations contained variation due to differences in protocol used, window/level technique and differences in interpretations of grey zones. Planning target volume delineations were varied due to protocol differences and extended parametrial tissue inclusion. All centres met EMBRACE II plan aims for PTV V and high-riskclinical target volume D EQD, despite variation in prescription dose, fractionation and treatment technique.
Brachytherapy target volume delineations are varied due to differences in contouring guidelines and protocols used. Planning target volume delineations are varied due to the uncertainties surrounding the extent of parametrial involvement. Dosimetric optimisation is sufficient across all centres to satisfy EMBRACE II planning aims despite significant variation in protocols used.
Previous multi-institutional audits of cervical cancer radiotherapy practices have been performed in Europe and the USA. This study is the first of its kind to be performed in the UK.
评估由于观察者间差异和方案差异，多个英国中心在勾画和剂量优化方面的变化程度。
将 2 例接受过外照射放疗（EBRT）和近距离放疗的宫颈癌患者的 CT/MR 图像分发给 11 个英国中心。各中心按照当地方案勾画结构并制定治疗计划。通过应用原始治疗计划对危及器官进行剂量评估，并根据靶区勾画的绝对体积变化以及长度、宽度和高度的变化来评估靶区勾画的变化。评估了所有中心以及遵循 EMBRACE II 的中心之间的治疗计划变化。使用总 EQD 评估治疗计划，并与 EMBRACE II 的剂量目标进行比较。还评估了腔内/间质近距离放疗联合治疗的变化。
由于使用的方案、窗宽/窗位技术和灰区解释的差异，近距离放疗靶区勾画存在变化。由于方案差异和扩展宫旁组织包括，计划靶区勾画也存在差异。尽管处方剂量、分割和治疗技术存在差异，但所有中心均满足 EMBRACE II 对 PTV V 和高危临床靶区 D EQD 的计划目标。
由于勾画指南和使用的方案存在差异，近距离放疗靶区勾画存在变化。由于宫旁受累程度的不确定性，计划靶区勾画存在变化。尽管使用的方案存在显著差异，但所有中心的剂量优化都足以满足 EMBRACE II 的计划目标。
以前在欧洲和美国进行了多机构宫颈癌放疗实践的审核。本研究是在英国进行的此类研究中的首例。
