Xin Mei, Li Lianghua, Wang Cheng, Shao Hongda, Liu Jianjun, Zhang Chenpeng
Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Front Neurol. 2023 May 16;14:1153779. doi: 10.3389/fneur.2023.1153779. eCollection 2023.
Total-body PET/CT equipment, uEXPLORER, is a newly developed imaging technology with a superior resolution, high sensitivity, and high signal-to-noise ratio, providing unique application advantages in the pharmacokinetic evaluation of positron tracers. While C-CFT PET/CT has been widely utilized in the early diagnosis of Parkinson's disease (PD), it is limited by the short half-life of the radionuclide and an incomplete understanding of its biological distribution in humans. This study aimed to use a total-body PET/CT dynamic scan with C-CFT imaging to describe the real-time internal biodistribution in PD patients and to obtain accurate radiation dosimetry.
Six male subjects with suspected PD underwent dynamic C-CFT total-body PET/CT. Following a bedside intravenous bolus injection of 373.3 ± 71.56 MBq of C-CFT, PET acquisition was performed synchronously for 75 min with a maximum axial field of view (AFOV) of 194 cm. Time-activity curves (TACs) were generated by delineating volumes of interest (VOIs) of the sourced organs using PMOD software. Tracer kinetics and cumulative organ activities were calculated, and absorbed doses were calculated and estimated using the OLINDA/EXM software.
In the systemic TAC analysis of C-CFT, several unique types of distribution patterns were obtained among several major organs, including a "Fast-in Fast-out" pattern in the kidneys, lungs, spleen, and thyroid, a "Fast-in Slow-out" curve in the heart wall, a "Slow-in Slow-out" mode in the liver, a "Low-level extending" pattern in the whole brain and muscle, and a "Slow-in to plateau" trend in the striatum and bone. The effective dose of C-CFT was calculated to be 2.83E-03 mSv/MBq, which is only one-third of the literature value measured by the conventional method. Moreover, this dose is much lower compared to all other doses of DAT radioligands used in PET imaging.
This study is a pioneering application of total-body PET/CT to C-CFT dynamic imaging. Our results confirmed that C-CFT has a favorable total body biodistribution, an extremely low internal radiation dose, and high imaging quality, making it suitable for reasonable PD diagnosis in patients requiring multiple follow-up examinations.
全身正电子发射断层显像/计算机断层扫描（PET/CT）设备uEXPLORER是一项新开发的成像技术，具有卓越的分辨率、高灵敏度和高信噪比，在正电子示踪剂的药代动力学评估中具有独特的应用优势。虽然C-CFT PET/CT已广泛用于帕金森病（PD）的早期诊断，但它受限于放射性核素的短半衰期以及对其在人体生物分布的不完全了解。本研究旨在使用C-CFT成像的全身PET/CT动态扫描来描述PD患者体内的实时生物分布，并获得准确的辐射剂量学数据。
6名疑似PD的男性受试者接受了C-CFT全身PET/CT动态扫描。在床边静脉推注373.3±71.56 MBq的C-CFT后，以最大轴向视野（AFOV）为194 cm同步进行75分钟的PET采集。使用PMOD软件通过勾勒源器官的感兴趣区（VOI）生成时间-活度曲线（TAC）。计算示踪剂动力学和累积器官活度，并使用OLINDA/EXM软件计算和估计吸收剂量。
在C-CFT的全身TAC分析中，在几个主要器官中获得了几种独特的分布模式，包括肾脏、肺、脾脏和甲状腺中的“快进快出”模式，心壁中的“快进慢出”曲线，肝脏中的“慢进慢出”模式，全脑和肌肉中的“低水平延伸”模式，以及纹状体和骨骼中的“慢进至平台期”趋势。计算得出C-CFT的有效剂量为2.83E-03 mSv/MBq，仅为传统方法测量的文献值的三分之一。此外，与PET成像中使用的所有其他多巴胺转运体（DAT）放射性配体剂量相比，该剂量要低得多。
本研究是全身PET/CT在C-CFT动态成像中的开创性应用。我们的结果证实，C-CFT具有良好的全身生物分布、极低的体内辐射剂量和高成像质量，使其适用于需要多次随访检查的患者进行合理的PD诊断。
