Effects of ferumoxytol on quantitative PET measurements in simultaneous PET/MR whole-body imaging: a pilot study in a baboon model
Effects of ferumoxytol on quantitative PET measurements in simultaneous PET/MR whole-body imaging: a pilot study in a baboon model
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DOI：
10.1186/s40658-015-0109-0
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发表时间：
2015-12-01
期刊：
影响因子：
4
通讯作者：
Hooker, Jacob M.
中科院分区：
文献类型：
--
作者：
Borra, Ronald J. H.;Cho, Hoon-Sung;Hooker, Jacob M.
背景：同步PET/MR成像依赖于MR导出的衰减图（mu图），用于PET数据的准确衰减校正。目前，这些地图是从梯度回波为基础的MR序列，这是敏感的磁化率变化。氧化铁磁性纳米颗粒已被用于测量血容量、肿瘤微血管、肿瘤相关巨噬细胞和表征淋巴结。在这项研究中，我们的目的是评估是否与氧化铁纳米粒子的敏感性影响可能会影响测量的F-18-FDG PET标准化摄取值（SUV）通过影响MR衍生的衰减maps.Methods的影响：该研究方案是由机构动物护理和使用委员会批准。使用Siemens Biograph mMR PET/MR扫描仪，我们使用琼脂糖体模评估了浓度增加的ferumoxytol和ferumoxytol聚集体对MR衍生的μ-图的影响。此外，我们进行了一个狒狒实验，评价单静脉注射ferumoxytol剂量（10 mg/kg）对肝脏，脾脏和胰腺F-18-FDG SUV在基线（ferumoxytol-naive），在第一个小时内，并在1，3，5，和11 weeks.Results的影响：幻影实验显示μ-map文物开始在ferumoxytol聚集体浓度为10至20 mg/kg。在体内狒狒的数据表明，观察到的F-18-FDG SUV的第一个小时内在肝脏，持续至少11 weeks.Conclusions：一个单一的ferumoxytol剂量可以影响测量SUV至少3个月，这应该考虑到当给药ferumoxytol的患者需要顺序PET/MR scannes.Advances in knowledge 1。在大约10 mg/kg的临床剂量水平下，ferumoxytol聚集体（而非单独的ferumoxytol）在MR衍生衰减校正图中产生显著伪影。当同时进行全身F-18-FDG PET/MR时，单剂量的ferumoxytol可导致观察到的SUV降低高达53%，这取决于所研究组织中ferumoxytol聚集体的量。在同时进行PET/MRI检查的情况下，ferumoxytol的剂量可能导致观察到的SUV发生长时间变化。这些潜在的变化应特别考虑当给药ferumoxytol的患者预期未来的PET/MR研究，因为ferumoxytol诱导的SUV的变化可能会干扰治疗评估。
Background: Simultaneous PET/MR imaging depends on MR-derived attenuation maps (mu-maps) for accurate attenuation correction of PET data. Currently, these maps are derived from gradient-echo-based MR sequences, which are sensitive to susceptibility changes. Iron oxide magnetic nanoparticles have been used in the measurement of blood volume, tumor microvasculature, tumor-associated macrophages, and characterizing lymph nodes. Our aim in this study was to assess whether the susceptibility effects associated with iron oxide nanoparticles can potentially affect measured F-18-FDG PET standardized uptake values (SUV) through effects on MR-derived attenuation maps.Methods: The study protocol was approved by the Institutional Animal Care and Use Committee. Using a Siemens Biograph mMR PET/MR scanner, we evaluated the effects of increasing concentrations of ferumoxytol and ferumoxytol aggregates on MR-derived mu-maps using an agarose phantom. In addition, we performed a baboon experiment evaluating the effects of a single i.v. ferumoxytol dose (10 mg/kg) on the liver, spleen, and pancreas F-18-FDG SUV at baseline (ferumoxytol-naive), within the first hour and at 1, 3, 5, and 11 weeks.Results: Phantom experiments showed mu-map artifacts starting at ferumoxytol aggregate concentrations of 10 to 20 mg/kg. The in vivo baboon data demonstrated a 53% decrease of observed F-18-FDG SUV compared to baseline within the first hour in the liver, persisting at least 11 weeks.Conclusions: A single ferumoxytol dose can affect measured SUV for at least 3 months, which should be taken into account when administrating ferumoxytol in patients needing sequential PET/MR scans.Advances in knowledge1. Ferumoxytol aggregates, but not ferumoxytol alone, produce significant artifacts in MR-derived attenuation correction maps at approximate clinical dose levels of 10 mg/kg.2. When performing simultaneous whole-body F-18-FDG PET/MR, a single dose of ferumoxytol can result in observed SUV decreases up to 53%, depending on the amount of ferumoxytol aggregates in the studied tissue.Implications for patient careAdministration of a single, clinically relevant, dose of ferumoxytol can potentially result in changes in observed SUV for a prolonged period of time in the setting of simultaneous PET/MR. These potential changes should be considered in particular when administering ferumoxytol to patients with expected future PET/MR studies, as ferumoxytol-induced SUV changes might interfere with therapy assessment.