The aim of this study was to evaluate the use of a Bayesian penalized likelihood reconstruction algorithm (Q.Clear) for 89Zr-immunoPET image reconstruction and its potential to improve image quality and reduce the administered activity of 89Zr-immunoPET tracers. Eight 89Zr-immunoPET whole-body PET/CT scans from three 89Zr-immunoPET clinical trials were selected for analysis. On average, patients were imaged 6.3 days (range 5.0–8.0 days) after administration of 69 MBq (range 65–76 MBq) of [89Zr]Zr-DFO-daratumumab, [89Zr]Zr-DFO-pertuzumab, or [89Zr]Zr-DFO-trastuzumab. List-mode PET data was retrospectively reconstructed using Q.Clear with incremental β-values from 150 to 7200, as well as standard ordered-subset expectation maximization (OSEM) reconstruction (2-iterations, 16-subsets, a 6.4-mm Gaussian transaxial filter, “heavy” z-axis filtering and all manufacturers’ corrections active). Reduced activities were simulated by discarding 50% and 75% of original counts in each list mode stream. All reconstructed PET images were scored for image quality and lesion detectability using a 5-point scale. SUVmax for normal liver and sites of disease and liver signal-to-noise ratio were measured. Q.Clear reconstructions with β = 3600 provided the highest scores for image quality. Images reconstructed with β-values of 3600 or 5200 using only 50% or 25% of the original counts provided comparable or better image quality scores than standard OSEM reconstruction images using 100% of counts. The Bayesian penalized likelihood reconstruction algorithm Q.Clear improved the quality of 89Zr-immunoPET images. This could be used in future studies to improve image quality and/or decrease the administered activity of 89Zr-immunoPET tracers.

中文翻译：

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使用贝叶斯惩罚似然重建算法改进的^89个Zr-immunoPET研究的图像重建

这项研究的目的是评估使用贝叶斯惩罚似然重建算法（Q.Clear）进行89Zr-immunoPET图像重建，以及其改善图像质量和减少89Zr-immunoPET示踪剂给药活性的潜力。从三项89Zr-immunoPET临床试验中选择八次89Zr-immunoPET全身PET / CT扫描进行分析。平均而言，在对[89Zr] Zr-DFO-daratumumab，[89Zr] Zr-DFO-pertuzumab或[89Zr]施用69 MBq（范围65-76 MBq）后的6.3天（范围为5.0-8.0天） Zr-DFO-曲妥珠单抗。使用Q.Clear回顾性地重建列表模式的PET数据，其β值从150到7200，以及标准有序子集期望最大化（OSEM）重建（2迭代，16个子集，6.4 mm高斯跨轴）过滤，“重” z轴过滤和所有制造商的校正处于活动状态）。通过减少每个列表模式流中原始计数的50％和75％来模拟减少的活动。使用5点量表对所有重建的PET图像的图像质量和病变可检测性进行评分。测量了正常肝脏，疾病部位和肝信噪比的SUVmax。β= 3600的Q.Clear重建图像质量最高。仅使用原始计数的50％或25％用3600或5200的β值重建的图像，与使用100％计数的标准OSEM重建图像相比，图像质量得分可比或更高。贝叶斯惩罚似然重建算法Q.Clear提高了89Zr-immunoPET图像的质量。