Department of Radiation Oncology, Seoul National University Bundang Hospital, 82 Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, 13620, Gyeonggi-do, Korea.
Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.
Radiat Oncol. 2021 Jun 13;16(1):109. doi: 10.1186/s13014-021-01836-z.
The present study aimed to propose a new foetal shielding device for pregnant cancer patients to reduce the foetal dose associated with treatment techniques using multiple gantry angles, such as intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT).
Three shielding structures were designed to minimise the scattered and leaked radiation from various gantry angles and radiation scattering within the patient. The base-plate part that can be placed on the treatment couch was designed to reduce the scattered and leaked radiation generated at gantry angles located near 180°. A body shielding part that can cover the lower chest and abdomen was designed, and a neck-shielding structure was added to reduce the internal and external radiation scattering from the treatment area. Evaluation plans were generated to assess the foetal dose reduction by the foetal shielding device in terms of the shielding material thickness, distance from the field edge, and shielding component using the flattened 6 MV photon beam (6MV) and flattening filter-free 6 MV photon beam (6MV-FFF). In addition, the effectiveness of the foetal shielding device was evaluated in a pregnant brain tumour patient.
The shielding material consisting of three parts was placed on frames composed of four arch shapes with a vertical curved structure, connection bar at the top position, and base plate. Each shielding part resulted in reductions in the radiation dose according to the treatment technique, as the thickness of the shielding material increased and the foetal dose decreased. In addition, a foetal dose reduction of approximately 50% was confirmed at 50 cm from the field edge by using the designed shielding device in most delivery techniques. In patients, the newly designed shielding structures can effectively eliminate up to about 49% of the foetal dose generated from various gantry angles used in VMAT or IMRT.
We designed a foetal shielding device consisting of three parts to effectively reduce the dose delivered to the foetus, and evaluated the device with various treatment techniques for a pregnant patient with brain tumour. The foetal shielding device shielded the scattered/leaked radiation from the treatment machine, and also effectively reduced internal scattering from the treatment area in the patient.
本研究旨在为孕妇癌症患者提出一种新的胎儿屏蔽装置，以降低使用多机架角度治疗技术（如调强放疗（IMRT）或容积调强弧形治疗（VMAT））时与胎儿相关的剂量。
设计了三种屏蔽结构，以最小化来自各种机架角度的散射和泄漏辐射以及患者内的辐射散射。设计了可放置在治疗台上的底板部分，以减少在接近 180°的机架角度处产生的散射和泄漏辐射。设计了可覆盖下胸部和腹部的身体屏蔽部分，并增加了颈部屏蔽结构，以减少来自治疗区域的内外辐射散射。使用平坦化 6MV 光子束（6MV）和无平坦化滤波器 6MV 光子束（6MV-FFF）生成评估计划，以评估屏蔽材料厚度、距射野边缘的距离和屏蔽组件对胎儿屏蔽装置降低胎儿剂量的效果。此外，还在一位孕妇脑肿瘤患者中评估了胎儿屏蔽装置的有效性。
将由三个部分组成的屏蔽材料放置在由四个弧形结构组成的框架上，该框架具有垂直弯曲结构、顶部的连接条和底板。随着屏蔽材料厚度的增加和胎儿剂量的降低，每个屏蔽部分都根据治疗技术导致辐射剂量的降低。此外，在使用大多数分娩技术时，在距射野边缘 50cm 处使用设计的屏蔽装置可确认胎儿剂量降低约 50%。在患者中，新设计的屏蔽结构可有效消除 VMAT 或 IMRT 中使用的各种机架角度产生的约 49%的胎儿剂量。
我们设计了一种由三个部分组成的胎儿屏蔽装置，以有效降低胎儿所接受的剂量，并使用各种治疗技术对脑肿瘤孕妇进行了评估。胎儿屏蔽装置屏蔽了来自治疗机器的散射/泄漏辐射，并且还有效减少了患者治疗区域内的内部散射。
