Preclinical imaging characteristics and quantification of Platinum-195m SPECT
Preclinical imaging characteristics and quantification of Platinum-195m SPECT
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DOI：
10.1007/s00259-017-3643-2
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发表时间：
2017-08-01
影响因子：
9.1
通讯作者：
Vogel, Wouter V.
中科院分区：
文献类型：
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作者：
Aalbersberg, E. A.;de Wit-van der Veen, B. J.;Vogel, Wouter V.
铂类化合物的体内生物分布成像可以更好地选择化疗（放疗）治疗的患者。用铂-195m（Pt-195 m）进行放射性标记允许SPECT成像，而不改变化合物的化学结构或生物活性。我们已经评估了Pt-195 m SPECT成像在小鼠中的可行性，目的是确定当前临床前成像设备的图像质量和定量准确性。在荷兰Petten（NRG）的高通量反应堆（HFR）中辐照富集（> 96%）Pt-194。获得比活度为33 MBq/mg的0.05 M HCl Pt-195 m-溶液。评估NanoSPECT/CT（Bioscan Inc.，华盛顿，美国）和U-SPECT+/CT（MILabs BV，乌得勒支，荷兰）扫描仪。以不同的采集持续时间（10-120 min）扫描填充有1 MBq Pt-195 m的放射性填充杆体模（杆直径0.85-1.7 mm）。四只健康小鼠静脉注射3-4 MBq Pt-195 m。在注射后0、2、4或24 h，用NanoSPECT采集小鼠图像120 min。描绘器官以定量Pt-195 m浓度。扫描后立即处死小鼠，使用伽马计数器和石墨炉原子吸收光谱法（GF-AAS）作为参考标准测定器官中的铂浓度。对体模进行30分钟采集，为两种扫描仪提供视觉上足够的图像质量。NanoSPECT上的最小可见杆直径为0.95 mm，U-SPECT+上的最小可见杆直径为0.85 mm。小鼠中的图像质量在视觉上是足够的。在肾脏、肝脏、血液和肠道中观察到摄取，并排泄至膀胱。脑内未见摄取。SPECT与γ计数器之间的斯皮尔曼相关性为0.92，SPECT与GF-AAS之间的相关性为0.84，GF-AAS与γ计数器之间的相关性为0.97（均p < 0.0001）。
In vivo biodistribution imaging of platinum-based compounds may allow better patient selection for treatment with chemo(radio)therapy. Radiolabeling with Platinum-195m (Pt-195m) allows SPECT imaging, without altering the chemical structure or biological activity of the compound. We have assessed the feasibility of Pt-195m SPECT imaging in mice, with the aim to determine the image quality and accuracy of quantification for current preclinical imaging equipment.Enriched (> 96%) Pt-194 was irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands (NRG). A 0.05 M HCl Pt-195m-solution with a specific activity of 33 MBq/mg was obtained. Image quality was assessed for the NanoSPECT/CT (Bioscan Inc., Washington DC, USA) and U-SPECT+/CT (MILabs BV, Utrecht, the Netherlands) scanners. A radioactivity-filled rod phantom (rod diameter 0.85-1.7 mm) filled with 1 MBq Pt-195m was scanned with different acquisition durations (10-120 min). Four healthy mice were injected intravenously with 3-4 MBq Pt-195m. Mouse images were acquired with the NanoSPECT for 120 min at 0, 2, 4, or 24 h after injection. Organs were delineated to quantify Pt-195m concentrations. Immediately after scanning, the mice were sacrificed, and the platinum concentration was determined in organs using a gamma counter and graphite furnace - atomic absorption spectroscopy (GF-AAS) as reference standards.A 30-min acquisition of the phantom provided visually adequate image quality for both scanners. The smallest visible rods were 0.95 mm in diameter on the NanoSPECT and 0.85 mm in diameter on the U-SPECT+. The image quality in mice was visually adequate. Uptake was seen in the kidneys with excretion to the bladder, and in the liver, blood, and intestine. No uptake was seen in the brain. The Spearman correlation between SPECT and gamma counter was 0.92, between SPECT and GF-AAS it was 0.84, and between GF-AAS and gamma counter it was0.97 (all p < 0.0001).Preclinical Pt-195m SPECT is feasible with acceptable tracer doses and acquisition times, and provides good image quality and accurate signal quantification.