Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, USA.
Department of Biomaterials Science and Technology, University of Twente, Enschede, The Netherlands.
Sci Rep. 2021 Jan 12;11(1):533. doi: 10.1038/s41598-020-79900-z.
Current therapy for hypervascular cancers, e.g., hepatocellular carcinoma, includes occlusion of the tumor blood supply by arterial infusion of embolic microspheres (beads) suspended in iodine-based contrast under fluoroscopic guidance. Available radiopaque, imageable beads use iodine as the radiopacifier and cannot be differentiated from contrast. This study aimed to synthesize and characterize imageable beads using bismuth as the radiopacifier that could be distinguished from iodine contrast based upon the difference in the binding energy of k-shell electrons (k-edge). Radiodense bismuth beads were successfully synthesized some with uniform bismuth distribution across the beads. The beads were spherical and could be infused through clinical microcatheters. The bismuth beads could be imaged with clinical dual-energy computed tomography (CT), where iodine-based contrast could be distinguished from the microspheres. The ability to separate iodine from bismuth may enhance the diagnostic information acquired on follow-up CT, identifying the distribution of the embolic beads separately from the contrast. Furthermore, with sequential use of iodine- and bismuth-based beads, the two radiopaque beads could be spatially distinguished on imaging, which may enable the development of dual drug delivery and dual tracking.
目前，针对富血管性癌症（如肝细胞癌）的治疗方法包括在透视引导下经动脉输注碘基造影剂混悬的栓塞微球（微球）以阻断肿瘤血供。现有的放射性可显影的微球使用碘作为放射增强剂，与造影剂无法区分。本研究旨在合成并表征使用铋作为放射增强剂的可显影微球，其可基于 k 壳层电子（k 边）结合能的差异与碘造影剂区分开来。成功合成了一些放射性密度高的铋微球，其在微球中具有均匀的铋分布。这些微球呈球形，可通过临床微导管输注。可使用临床双能 CT 进行铋微球成像，其中碘基造影剂可与微球区分开来。将碘与铋分离的能力可能会增强在后续 CT 上获得的诊断信息，将栓塞微球的分布与造影剂分开识别。此外，通过碘基和铋基微球的顺序使用，在成像上可在空间上区分这两种不透射线的微球，这可能有助于开发双重药物输送和双重追踪。
