Fusella M, Alvarez Andres E, Villegas F, Milan L, Janssen T M, Dal Bello R, Garibaldi C, Placidi L, Cusumano D
Abano Terme Hospital, Department of Radiation Oncology, Abano Terme (Padua), Italy.
OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
Phys Imaging Radiat Oncol. 2024 Sep 26;32:100652. doi: 10.1016/j.phro.2024.100652. eCollection 2024 Oct.
The emergence of synthetic CT (sCT) in MR-guided radiotherapy (MRgRT) represents a significant advancement, supporting MR-only workflows and online treatment adaptation. However, the lack of consensus guidelines has led to varied practices. This study reports results from a 2023 ESTRO survey aimed at defining current practices in sCT development and use.
An survey was distributed to ESTRO members, including 98 questions across four sections on sCT algorithm generation and usage. By June 2023, 100 centers participated. The survey revealed diverse clinical experiences and roles, with primary sCT use in the pelvis (60%), brain (15%), abdomen (11%), thorax (8%), and head-and-neck (6%). sCT was mostly used for conventional fractionation treatments (68%), photon SBRT (40%), and palliative cases (28%), with limited use in proton therapy (4%).
Conditional GANs and GANs were the most used neural network architectures, operating mainly on 1.5 T and 3 T MRI images. Less than half used paired images for training, and only 20% performed image selection. Key MR image quality parameters included magnetic field homogeneity and spatial integrity. Half of the respondents lacked a dedicated sCT-QA program, and many did not apply sanitychecks before calculation. Selection strategies included age, weight, and metal artifacts. A strong consensus (95%) emerged for vendor neutral guidelines.
The survey highlights the need for expert-based, vendor-neutral guidelines to standardize sCT tools, metrics, and clinical protocols, ensuring effective sCT use in MR-guided radiotherapy.
合成CT（sCT）在磁共振引导放疗（MRgRT）中的出现代表了一项重大进展，支持仅使用磁共振的工作流程和在线治疗适应性调整。然而，缺乏共识性指南导致了实践的差异。本研究报告了2023年欧洲放射肿瘤学会（ESTRO）一项调查的结果，该调查旨在确定sCT开发和使用的当前实践情况。
向ESTRO成员发放了一份调查问卷，包括关于sCT算法生成和使用的四个部分的98个问题。截至2023年6月，有100个中心参与。调查显示了不同的临床经验和角色，sCT主要用于骨盆（60%）、脑部（15%）、腹部（11%）、胸部（8%）和头颈（6%）。sCT大多用于常规分割治疗（68%）、光子立体定向体部放疗（40%）和姑息治疗病例（28%），在质子治疗中的使用有限（4%）。
条件生成对抗网络（Conditional GANs）和生成对抗网络（GANs）是使用最多的神经网络架构，主要在1.5T和3T磁共振图像上运行。不到一半的机构使用配对图像进行训练，只有20%进行图像选择。关键的磁共振图像质量参数包括磁场均匀性和空间完整性。一半的受访者缺乏专门的sCT质量保证计划，许多人在计算前未进行合理性检查。选择策略包括年龄、体重和金属伪影。对于供应商中立的指南达成了强烈共识（95%）。
该调查强调需要基于专家的、供应商中立的指南来规范sCT工具、指标和临床方案，以确保sCT在磁共振引导放疗中的有效使用。
