Carlton Hayden, Salimi Marzieh, Arepally Nageshwar, Bentolila Gabriela, Sharma Anirudh, Bibic Adnan, Newgren Matt, Goodwill Patrick, Attaluri Anilchandra, Korangath Preethi, Bulte Jeff W M, Ivkov Robert
Department of Radiation Oncology and Molecular Radiation Sciences the Johns Hopkins University School of Medicine Baltimore MD 21231 USA.
Russell H. Morgan Department of Radiology and Radiological Science Division of MR Research the Johns Hopkins University School of Medicine Baltimore MD 21205 USA.
Adv Funct Mater. 2025 Jan 9;35(2):2412321. doi: 10.1002/adfm.202412321. Epub 2024 Oct 18.
Magnetic particle imaging (MPI) is an emerging modality that can address longstanding technological challenges encountered with magnetic particle hyperthermia (MPH) cancer therapy. MPI is a tracer technology compatible with MPH for which magnetic nanoparticles (MNPs) provide signal for MPI and heat for MPH. Identifying whether a specific MNP formulation is suitable for both modalities is essential for clinical implementation. Current models predict that functional requirements of each modality impose conflicting demands on nanoparticle magnetic properties. This objective here is to develop a measurement and ranking scheme based on end-use performance to streamline evaluation of candidate MNP formulations. The measured MPI point-spread function (PSF) and specific loss power (SLP) is combined to generate a single numerical value for comparison on a relative ranking scale, or figure of merit (FoM). 12 aqueous iron-containing formulations are evaluated, including FDA-approved (parenteral) iron-containing colloids. MNPs with high (Synomag-D70: 123.4), medium (Synomag-D50: 63.2), and low (NanoXact: 0.147) FoM values are selected for in vivo validation of the selection scheme in subcutaneous 4T1 tumors. Results demonstrate that the proposed ranking accurately assessed the relative performance of MNPs for MPI and MPH. Data demonstrated that image quality and tumor temperature rise increased with FoM ranking, validating predictions. It isshown that the MPI signal correlated with MNP concentration in tissue. Computational heat transfer models anchored on tumor MPI data harmonized with experimental results to within an average of 2 °C when MNP content estimated from MPI data is included. Computational studies emphasized the importance of post-injection MNP quantitation and MPI spatial resolution.
磁粒子成像（MPI）是一种新兴的成像方式，它能够解决磁粒子热疗（MPH）癌症治疗中长期存在的技术挑战。MPI是一种与MPH兼容的示踪技术，其中磁性纳米颗粒（MNP）为MPI提供信号，为MPH提供热量。确定特定的MNP制剂是否适用于这两种方式对于临床应用至关重要。当前模型预测，每种方式的功能要求对纳米颗粒的磁性提出了相互冲突的要求。这里的目标是基于最终使用性能开发一种测量和排序方案，以简化对候选MNP制剂的评估。将测得的MPI点扩散函数（PSF）和比损耗功率（SLP）结合起来，生成一个单一的数值，以便在相对排名尺度或品质因数（FoM）上进行比较。对12种含水铁制剂进行了评估，包括美国食品药品监督管理局（FDA）批准的（肠胃外）含铁胶体。选择具有高（Synomag-D70：123.4）、中（Synomag-D50：63.2）和低（NanoXact：0.147）FoM值的MNP用于皮下4T1肿瘤中选择方案的体内验证。结果表明，所提出的排名准确地评估了MNP在MPI和MPH方面的相对性能。数据表明，图像质量和肿瘤温度升高随着FoM排名的增加而增加，验证了预测结果。结果表明，MPI信号与组织中的MNP浓度相关。当纳入从MPI数据估计的MNP含量时，基于肿瘤MPI数据的计算传热模型与实验结果的平均偏差在2°C以内。计算研究强调了注射后MNP定量和MPI空间分辨率的重要性。
