Fagerstrom Jessica M, Kaur Sukhjit
Northwest Medical Physics Center, Lynnwood, WA, USA.
Kaiser Permanente, Seattle, WA, USA.
J Appl Clin Med Phys. 2020 Nov;21(11):283-287. doi: 10.1002/acm2.13039. Epub 2020 Oct 5.
A new high dose rate (HDR) brachytherapy program was initiated in a community hospital setting, with the goal of using magnetic resonance (MR) images with the implant in place during the planning process. Physics acceptance testing and commissioning was completed for key program components, including multiple applicators. To image new applicators for MRI-based planning prior to use with patients, agar gel doped with copper sulfate was created using simple, MR-safe household materials as a practical and inexpensive alternative to custom-machined precision phantoms. Applicators in-phantom were scanned in a 1.5 T MRI scanner using the same sequences developed for the brachytherapy program, then rigidly registered to high-resolution computed tomography (CT) images to assess distortion, artifact, and geometric displacement. To date, Varian tandem and ring sets, segmented cylinders, cervical probes, endometrial applicators; and third-party plastic needles, tandems, and vaginal guides have been imaged in phantom and are available for use clinically.
在一家社区医院启动了一项新的高剂量率（HDR）近距离放射治疗计划，目标是在治疗计划过程中使用植入物在位时的磁共振（MR）图像。已完成对包括多个施源器在内的关键计划组件的物理验收测试和调试。为了在将新的施源器用于患者之前对基于MRI的计划进行成像，使用简单的、MR安全的家用材料制作了掺杂硫酸铜的琼脂凝胶，作为定制加工精密模体的实用且廉价的替代品。将置于模体内的施源器在1.5T MRI扫描仪中使用为近距离放射治疗计划开发的相同序列进行扫描，然后与高分辨率计算机断层扫描（CT）图像进行刚性配准，以评估畸变、伪影和几何位移。迄今为止，Varian串联和环形装置、分段圆柱体、宫颈探头、子宫内膜施源器；以及第三方塑料针、串联装置和阴道导板已在模体内成像，可用于临床。
