Department, of Nuclear Medicine, Hôpital Erasme, Université libre de Bruxelles (ULB), Brussels, Belgium.
Department of Gastroenterology, Hôpital Erasme, Université libre de Bruxelles (ULB), Brussels, Belgium.
Med Phys. 2022 Dec;49(12):7567-7582. doi: 10.1002/mp.15880. Epub 2022 Aug 8.
Selective internal radiotherapy based on transarterial radioembolization (TARE) with yttrium-90 ( Y) microspheres is an established treatment for primary or metastatic liver disease.
The objective of this work is to optimize the dosimetry of patients treated with Y TARE, using positron emission tomography (PET) images.
The NEMA 2012 PET phantom was filled with nearly 3.9 GBq of Y activity and acquired at days 0, 3, 5, 7, and 9 on a classic time-of-flight PET/computed tomography (CT) scanner (Philips TF64) and on a silicon photomultiplier (SiPM)-based PET/CT scanner (Philips Vereos). Acquisitions were carried on following the guidelines proposed in a previously published multicentric trial and images were reconstructed by varying and combining the available parameters. Comparisons were performed to identify the best set(s) of parameters leading to the most accurate Y-PET image(s), in terms of activity distribution. Then, for both scanners, the best images were analyzed with Simplicit Y, a personalized dosimetry software using multicompartmental Medical Internal Radiation Dose model. The comparison between measured and true doses allowed to identify the image granting the most consistent dose estimations and, therefore, to designate the set of parameters to be applied on patients' data for the reconstruction of optimized clinical images. Posttreatment dosimetry of four patients was then realized with Simplicit Y using optimized imaging datasets.
Based on activity distribution comparisons and dose estimations over phantom and patients data, the SiPM-based PET/CT system appeared more suitable than the photomultiplier tube-based TF64 for Y-PET imaging. With the SiPM-based PET/CT system, reconstructed images with a 2-mm voxel size combined with the application of the point spread function correction led to the most accurate results for quantitative Y measures.
For the SiPM-based PET/CT scanner, an optimized set of reconstruction parameters has been identified and applied on patients' data in order to generate the most accurate image to be used for an improved personalized Y-PET dosimetry, ensuring a reliable evaluation of the delivered doses.
基于经动脉放射性栓塞（TARE）的钇-90（Y）微球选择性内放射治疗是原发性或转移性肝脏疾病的既定治疗方法。
本研究旨在使用正电子发射断层扫描（PET）图像优化接受 Y TARE 治疗的患者的剂量学。
采用 NEMA 2012 PET 体模填充近 3.9GBq 的 Y 活度，在经典飞行时间 PET/计算机断层扫描（CT）扫描仪（Philips TF64）和基于硅光电倍增管（SiPM）的 PET/CT 扫描仪（Philips Vereos）上于 0、3、5、7 和 9 天进行采集。采集遵循先前发表的多中心试验中提出的指南，通过改变和组合可用参数进行图像重建。通过比较，确定在活性分布方面能产生最准确的 Y-PET 图像的最佳参数集。然后，使用个性化剂量计算软件 Simplicit Y，对两种扫描仪的最佳图像进行分析，该软件采用多室医学内部辐射剂量模型。对测量剂量与真实剂量进行比较，以确定提供最一致剂量估算的图像，并因此确定用于重建优化临床图像的参数集。然后使用优化的成像数据集通过 Simplicit Y 对 4 名患者进行治疗后剂量测定。
基于活性分布比较和对体模和患者数据的剂量估计，基于 SiPM 的 PET/CT 系统比基于光电倍增管的 TF64 更适合 Y-PET 成像。使用基于 SiPM 的 PET/CT 系统，当重建图像的体素大小为 2mm 并应用点扩展函数校正时，对定量 Y 测量结果最准确。
对于基于 SiPM 的 PET/CT 扫描仪，已确定并应用于患者数据的优化重建参数集，以生成最准确的图像，用于改进个性化 Y-PET 剂量学，确保对所给予剂量进行可靠评估。
