Metropolitan Hospital, Athens, Greece.
Radiother Oncol. 2012 Apr;103(1):113-22. doi: 10.1016/j.radonc.2011.12.024. Epub 2012 Jan 30.
The GYN GEC-ESTRO working group issued three parts of recommendations and highlighted the pivotal role of MRI for the successful implementation of 3D image-based cervical cancer brachytherapy (BT). The main advantage of MRI as an imaging modality is its superior soft tissue depiction quality. To exploit the full potential of MRI for the better ability of the radiation oncologist to make the appropriate choice for the BT application technique and to accurately define the target volumes and the organs at risk, certain MR imaging criteria have to be fulfilled. Technical requirements, patient preparation, as well as image acquisition protocols have to be tailored to the needs of 3D image-based BT. The present recommendation is focused on the general principles of MR imaging for 3D image-based BT. Methods and parameters have been developed and progressively validated from clinical experience from different institutions (IGR, Universities of Vienna, Leuven, Aarhus and Ljubljana) and successfully applied during expert meetings, contouring workshops, as well as within clinical and interobserver studies. It is useful to perform pelvic MRI scanning prior to radiotherapy ("Pre-RT-MRI examination") and at the time of BT ("BT MRI examination") with one MR imager. Both low and high-field imagers, as well as both open and close magnet configurations conform to the requirements of 3D image-based cervical cancer BT. Multiplanar (transversal, sagittal, coronal and oblique image orientation) T2-weighted images obtained with pelvic surface coils are considered as the golden standard for visualisation of the tumour and the critical organs. The use of complementary MRI sequences (e.g. contrast-enhanced T1-weighted or 3D isotropic MRI sequences) is optional. Patient preparation has to be adapted to the needs of BT intervention and MR imaging. It is recommended to visualise and interpret the MR images on dedicated DICOM-viewer workstations, which should also assist the contouring procedure. Choice of imaging parameters and BT equipment is made after taking into account aspects of interaction between imaging and applicator reconstruction, as well as those between imaging, geometry and dose calculation. In a prospective clinical context, to implement 3D image-based cervical cancer brachytherapy and to take advantage of its full potential, it is essential to successfully meet the MR imaging criteria described in the present recommendations of the GYN GEC-ESTRO working group.
妇科肿瘤放射治疗学-欧洲放射肿瘤学会（GYN GEC-ESTRO）工作组发布了三部分建议，强调磁共振成像（MRI）在成功实施基于三维图像的宫颈癌近距离治疗（BT）中的关键作用。MRI 作为一种成像方式的主要优势在于其出色的软组织描绘质量。为了充分发挥 MRI 的潜力，使放射肿瘤学家能够更好地选择 BT 应用技术，并准确定义靶区和危及器官，必须满足某些 MRI 成像标准。技术要求、患者准备以及图像采集方案必须根据基于三维图像的 BT 的需求进行调整。本建议侧重于基于三维图像的 BT 的 MRI 一般原则。方法和参数已从不同机构（IGR、维也纳大学、鲁汶大学、奥胡斯大学和卢布尔雅那大学）的临床经验中开发出来，并逐步得到验证，并在专家会议、勾画工作坊以及临床和观察者间研究中成功应用。在放疗前（“放疗前 MRI 检查”）和 BT 时（“BT MRI 检查”）使用一台 MRI 扫描仪对骨盆进行 MRI 扫描是有用的。低磁场和高磁场成像仪，以及开放式和封闭式磁体配置均符合基于三维图像的宫颈癌 BT 的要求。使用盆腔表面线圈获得的多平面（横断、矢状、冠状和斜向图像方位）T2 加权图像被认为是肿瘤和关键器官可视化的金标准。使用补充 MRI 序列（例如增强 T1 加权或 3D 各向同性 MRI 序列）是可选的。患者准备必须适应 BT 干预和 MRI 成像的需求。建议在专用的 DICOM 查看器工作站上可视化和解释 MRI 图像，该工作站还应辅助勾画过程。在考虑成像和施源器重建之间以及成像、几何形状和剂量计算之间的相互作用的情况下，选择成像参数和 BT 设备。在前瞻性临床环境中，要实施基于三维图像的宫颈癌 BT 并充分发挥其潜力，必须成功满足 GYN GEC-ESTRO 工作组本建议中描述的 MRI 成像标准。
