Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria.
Strahlenther Onkol. 2024 Aug;200(8):684-690. doi: 10.1007/s00066-024-02207-9. Epub 2024 Feb 26.
This study aimed to prospectively assess the visibility of interstitial needles on transrectal ultrasound (TRUS) in cervical cancer brachytherapy patients and evaluate its impact on implant and treatment plan quality.
TRUS was utilized during and after applicator insertion, with each needle's visibility documented through axial images at the high-risk clinical target volume's largest diameter. Needle visibility on TRUS was scored from 0 (no visibility) to 3 (excellent discrimination, margins distinct). Quantitative assessment involved measuring the distance between tandem and each needle on TRUS and comparing it to respective magnetic resonance imaging (MRI) measurements. Expected treatment plan quality based on TRUS images was rated from 1 (meeting all planning objectives) to 4 (violation of High-risk clinical target volume (CTV) and/or organ at risk (OAR) hard constraints) and compared to the final MRI-based plan.
Analysis included 23 patients with local FIGO stage IB2-IVA, comprising 41 applications with a total of 230 needles. A high visibility rate of 99.1% (228/230 needles) was observed, with a mean visibility score of 2.5 ± 0.7 for visible needles. The maximum and mean difference between MRI and TRUS measurements were 8 mm and -0.1 ± 1.6 mm, respectively, with > 3 mm discrepancies in 3.5% of needles. Expected treatment plan quality after TRUS assessment exactly aligned with the final MRI plan in 28 out of 41 applications with only minor deviations in all other cases.
Real-time TRUS-guided interstitial needle placement yielded high-quality implants, thanks to excellent needle visibility during insertion. This supports the potential of TRUS-guided brachytherapy as a promising modality for gynecological indications.
本研究旨在前瞻性评估宫颈癌近距离放疗中经直肠超声（TRUS）下间质针的可视性，并评估其对植入物和治疗计划质量的影响。
在施源器插入过程中和之后使用 TRUS，通过在高危临床靶区最大直径的轴位图像上记录每个针的可视性，对 TRUS 下的针可视性进行评分，从 0（不可见）到 3（极好区分，边缘明显）。通过在 TRUS 上测量间距和每个针的距离，并与相应的磁共振成像（MRI）测量值进行比较，对 TRUS 上的定量评估进行评估。根据 TRUS 图像预计的治疗计划质量从 1（满足所有计划目标）到 4（高危临床靶区（CTV）和/或危及器官（OAR）硬限制的违反）进行评分，并与最终基于 MRI 的计划进行比较。
分析包括局部 FIGO 分期 IB2-IVA 的 23 名患者，共进行了 41 次应用，共 230 根针。观察到 99.1%（228/230 根针）的高可见率，可见针的平均可视性评分为 2.5±0.7。MRI 和 TRUS 测量值之间的最大和平均差异分别为 8mm 和-0.1±1.6mm，3.5%的针存在>3mm的差异。在 41 个应用中，有 28 个应用的 TRUS 评估后的预期治疗计划与最终 MRI 计划完全一致，只有在所有其他情况下存在微小偏差。
由于插入过程中出色的针可视性，实时 TRUS 引导间质针放置产生了高质量的植入物，这支持了 TRUS 引导近距离放疗作为妇科适应证的一种有前途的治疗方式。
