Biltekin Fatih, Bäumer Christian, Esser Johannes, Ghanem Osamah, Ozyigit Gokhan, Timmermann Beate
Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
West German Proton Therapy Centre Essen (WPE), Essen, Germany.
Int J Part Ther. 2023 Apr 3;10(1):13-22. doi: 10.14338/IJPT-22-00035.1. eCollection 2023 Summer.
To evaluate the feasibility of the three-dimensional (3D) printed small animal phantoms in dosimetric verification of proton therapy for small animal radiation research.
Two different phantoms were modeled using the computed-tomography dataset of real rat and tumor-bearing mouse, retrospectively. Rat phantoms were designed to accommodate both EBT3 film and ionization chamber. A subcutaneous tumor-bearing mouse phantom was only modified to accommodate film dosimetry. All phantoms were printed using polylactic-acid (PLA) filament. Optimal printing parameters were set to create tissue-equivalent material. Then, proton therapy plans for different anatomical targets, including whole brain and total lung irradiation in the rat phantom and the subcutaneous tumor model in the mouse phantom, were created using the pencil-beam scanning technique. Point dose and film dosimetry measurements were performed using 3D-printed phantoms. In addition, all phantoms were analyzed in terms of printing accuracy and uniformity.
Three-dimensionally printed phantoms had excellent uniformity over the external body, and printing accuracy was within 0.5 mm. According to our findings, two-dimensional dosimetry with EBT3 showed acceptable levels of γ passing rate for all measurements except for whole brain irradiation (γ passing rate, 89.8%). In terms of point dose analysis, a good agreement (<0.1%) was found between the measured and calculated point doses for all anatomical targets.
Three-dimensionally printed small animal phantoms show great potential for dosimetric verifications of clinical proton therapy for small animal radiation research.
评估三维（3D）打印的小动物体模在小动物放射研究中质子治疗剂量验证的可行性。
回顾性地使用真实大鼠和荷瘤小鼠的计算机断层扫描数据集对两种不同的体模进行建模。大鼠体模设计为可容纳EBT3胶片和电离室。皮下荷瘤小鼠体模仅进行了修改以适应胶片剂量测定。所有体模均使用聚乳酸（PLA）细丝打印。设置最佳打印参数以创建组织等效材料。然后，使用笔形束扫描技术为不同的解剖靶点制定质子治疗计划，包括大鼠体模中的全脑和全肺照射以及小鼠体模中的皮下肿瘤模型。使用3D打印体模进行点剂量和胶片剂量测定。此外，对所有体模的打印精度和均匀性进行了分析。
三维打印体模在外部身体上具有出色的均匀性，打印精度在0.5毫米以内。根据我们的研究结果，除全脑照射外（γ通过率为89.8%），EBT3二维剂量测定在所有测量中的γ通过率均处于可接受水平。在点剂量分析方面，所有解剖靶点的测量点剂量与计算点剂量之间具有良好的一致性（<0.1%）。
三维打印的小动物体模在小动物放射研究的临床质子治疗剂量验证中显示出巨大潜力。
