Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK.
Gloucestershire Oncology Centre, Cheltenham General Hospital, Cheltenham, UK.
Radiother Oncol. 2021 Jun;159:112-118. doi: 10.1016/j.radonc.2021.03.015. Epub 2021 Mar 26.
This study compared MRI to CBCT for the identification and registration of lymph nodes (LN) in patients with locally advanced (LA)-NSCLC, to assess the suitability of targeting LNs in future MR-image guided radiotherapy (MRgRT) workflows.
Radiotherapy radiographers carried out Visual Grading Analysis (VGA) assessment of image quality, LN registration and graded their confidence in registration for each of the 24 LNs on CBCT and two MR sequences, MR1 (T2w Turbo Spin Echo) and MR2 (T1w DIXON water only image).
Pre-registration image quality assessment revealed MR1 and MR2 as significantly superior to CBCT in terms of image quality (p ≤ 0.01). No significant differences were noted in interobserver variability for LN registration between CBCT, MR1 and MR2. Observers were more confident in their MR registrations compared to their CBCT based LN registrations (p ≤ 0.02).
Interobserver setup correction variability was not found to be significantly different between CBCT and MR. Image quality and registration confidence were found to be superior for MRI sequences. This is a promising step towards MR-guided radiotherapy for the treatment of LA-NSCLC.
本研究比较了 MRI 与 CBCT 对局部晚期（LA）-NSCLC 患者淋巴结（LN）的识别和配准，以评估在未来的磁共振引导放疗（MRgRT）工作流程中对 LN 进行靶向的适用性。
放射治疗技师对 CBCT 和两种磁共振序列（MR1（T2w 涡轮自旋回波）和 MR2（T1w DIXON 仅水图像））上的 24 个 LN 的图像质量、LN 配准进行了视觉分级分析（VGA）评估，并对每个 LN 的配准进行了分级，并对其配准的置信度进行了分级。
在配准前的图像质量评估中，MR1 和 MR2 在图像质量方面明显优于 CBCT（p≤0.01）。在 CBCT、MR1 和 MR2 之间，LN 配准的观察者间变异性没有显著差异。观察者对其 MR 配准的信心比对其基于 CBCT 的 LN 配准的信心更高（p≤0.02）。
在 CBCT 和 MR 之间，观察者间的摆位校正变异性没有发现有显著差异。MRI 序列的图像质量和配准信心更高。这是朝着治疗 LA-NSCLC 的 MR 引导放疗迈出的有希望的一步。
