Fiagan Yawo A C, Bossuyt Evy, Nevens Daan, Dirix Piet, Theys Frank, Gevaert Thierry, Verellen Dirk
Iridium Netwerk, Radiation Oncology Department, Universiteit Antwerpen, Antwerp, Belgium.
Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium.
Tech Innov Patient Support Radiat Oncol. 2020 Nov 24;16:65-69. doi: 10.1016/j.tipsro.2020.10.005. eCollection 2020 Dec.
PURPOSE/OBJECTIVE: In all treatment sites of our radiotherapy network, in vivo dosimetry (PerFRACTION™) was fully implemented in February 2018. We hypothesized that additional help with bladder and rectum preparation by home nursing would improve patients' preparation and investigated if this could be assessed using in vivo dosimetry (IVD).
MATERIALS/METHODS: A retrospective study was conducted with a test group who received additional help with bladder and rectum preparation by home nurses and a control group who only received information on bladder and rectum preparation according to the standard protocol. Patients were treated with a 6 MV Volumetric Modulated Arc Therapy (VMAT) technique. Electronic portal imaging device (EPID)-based integrated transit dose images were acquired on the first 3 days of treatment and weekly thereafter or more if failed fractions (FF) occurred. Results were analyzed using a global gamma analysis with a threshold of 20%, tolerance of 5% (dose difference) and 5 mm (distance to agreement), and a passing level of 95%.
Data of 462 prostate patients was analyzed: 39 and 423 in a test and control group respectively with a comparable number of measurements (on average 8.0 (σ = 4.8) and 7.1 (σ = 4.5) respectively per treatment course). Of the FF, 39% and 31% were related to variations in bladder and rectum filling for the test and control group respectively. Subgroups were created based on the number of FF, no statistically significant differences were observed.
Two dimensional EPID-based IVD successfully detected deviations due to variations in bladder and rectum filling, however it could not confirm the hypothesis.
目的/目标：在我们放疗网络的所有治疗地点，体内剂量测定法（PerFRACTION™）于2018年2月全面实施。我们假设家庭护理在膀胱和直肠准备方面提供额外帮助会改善患者的准备情况，并研究这是否可以通过体内剂量测定法（IVD）进行评估。
材料/方法：进行了一项回顾性研究，设立了一个试验组，该组接受家庭护士在膀胱和直肠准备方面的额外帮助，以及一个对照组，该组仅根据标准方案接受膀胱和直肠准备的信息。患者采用6兆伏容积调强弧形治疗（VMAT）技术进行治疗。在治疗的前3天以及之后每周（如果出现失败分次（FF）则增加次数）采集基于电子门静脉成像设备（EPID）的综合传输剂量图像。使用全局γ分析对结果进行分析，阈值为20%，容差为5%（剂量差异）和5毫米（一致距离），通过水平为95%。
分析了462例前列腺癌患者的数据：试验组39例，对照组423例，测量次数相当（每个疗程平均分别为8.0（σ = 4.8）和7.1（σ = 4.5））。在FF中，试验组和对照组分别有39%和31%与膀胱和直肠充盈的变化有关。根据FF的数量创建亚组，但未观察到统计学上的显著差异。
基于二维EPID的IVD成功检测到由于膀胱和直肠充盈变化导致的偏差，然而未能证实该假设。
