Department of Radiation Oncology, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Austria.
Department of Oncology, Aarhus University Hospital, Denmark.
Radiother Oncol. 2019 Apr;133:149-155. doi: 10.1016/j.radonc.2019.01.012. Epub 2019 Jan 28.
The EMBRACE II study combines state-of-the-art Image-Guided Adaptive Brachytherapy in cervix cancer with an advanced protocol for external beam radiotherapy (EBRT) which specifies target volume selection, contouring and treatment planning. In EMBRACE II, well-defined EBRT is an integral part of the overall treatment strategy with the primary aim of improving nodal control and reducing morbidity. The EMBRACE II EBRT planning concept is based on improved conformality through relaxed coverage criteria for all target volumes. For boosting of lymph nodes, a simultaneous integrated boost and coverage probability planning is applied. Before entering EMBRACE II, institutes had to go through accreditation.
As part of accreditation, a treatment planning dummy-run included educational blocks and submission of an examination case provided by the study coordinators. Seventy-one centers submitted 123 EBRT dose distributions. Replanning was required if hard constraints were violated or planning concepts were not fully accomplished. Dosimetric parameters of original and revised plans were compared.
Only 11 plans violated hard constraints. Twenty-seven centers passed after first submission. 27 needed one and 13 centers needed more revisions. The most common reasons for revisions were low conformality, relatively high OAR doses or insufficient lymph node coverage reduction. Individual feedback on planning concepts improved plan quality considerably, resulting in a median body V43Gy reduction of 158 cm from first plan submission to approved plan.
A dummy-run as applied in EMBRACE II, consisting of training and examination cases enabled us to test institutes' treatment planning capabilities, and improve plan quality.
EMBRACE II 研究将先进的影像引导自适应近距离放疗技术与外部束放疗（EBRT）的先进方案相结合，该方案规定了靶区选择、勾画和治疗计划。在 EMBRACE II 中，明确的 EBRT 是整体治疗策略的一个组成部分，主要目的是改善淋巴结控制并降低发病率。EMBRACE II 的 EBRT 计划概念基于通过放宽所有靶区的覆盖标准来提高适形性。为了对淋巴结进行加强放疗，采用了同时的综合增敏和覆盖概率计划。在进入 EMBRACE II 之前，机构必须通过认证。
作为认证的一部分，治疗计划模拟运行包括教育模块和提交研究协调员提供的考试病例。71 个中心提交了 123 个 EBRT 剂量分布。如果违反了硬约束或未完全完成计划概念，则需要重新计划。比较了原始和修订计划的剂量学参数。
只有 11 个计划违反了硬约束。27 个中心在首次提交后通过。27 个需要一次修订，13 个需要更多修订。修订的最常见原因是适形性低、相对高的 OAR 剂量或淋巴结覆盖减少不足。对计划概念的个别反馈大大提高了计划质量，导致从首次计划提交到批准计划，中位数身体 V43Gy 减少了 158cm³。
EMBRACE II 应用的模拟运行，包括培训和考试病例，使我们能够测试机构的治疗计划能力，并提高计划质量。
