Rowe Christopher C, Jones Gareth, Doré Vincent, Pejoska Svetlana, Margison Laura, Mulligan Rachel S, Chan J Gordon, Young Kenneth, Villemagne Victor L
Department of Molecular Imaging, Austin Health, Melbourne, Australia Department of Medicine, University of Melbourne, Melbourne, Australia
Department of Molecular Imaging, Austin Health, Melbourne, Australia.
J Nucl Med. 2016 Aug;57(8):1233-7. doi: 10.2967/jnumed.115.171595. Epub 2016 Feb 16.
A common quantitative output value for PET measures of β-amyloid (Aβ) binding across tracers and methods would allow better comparison of data across sites and application of universal diagnostic and prognostic values. A method has recently been developed that generates a unit of measurement called the centiloid. We applied this method to 2-[2-(18)F-fluoro-6-(methylamino)-3-pyridinyl]-1-benzofuran-5-ol ((18)F-NAV4694) and (11)C-Pittsburgh compound B ((11)C-PiB) Aβ images to derive the scaling factor required to express tracer binding in centiloids.
Fifty-five participants, including 10 young controls (33 ± 7 y old), underwent both (11)C-PiB and (18)F-NAV4694 imaging no more than 3 mo apart, with the images acquired 50-70 min after tracer injection. The images were spatially normalized and analyzed using the standard centiloid method and regions (cortex and whole-cerebellum reference) downloaded from the Global Alzheimer Association Interactive Network website.
SUV ratios (SUVRs) showed a strong correlation in tracer binding ((18)F-NAV4694 SUVR = 1.09 × (11)C-PiB SUVR - 0.08, R(2) = 0.99). The equation to convert (18)F-NAV4694 to centiloids [100 × ((18)F-NAV4694 SUVR - 1.028)/1.174] was similar to a published equation for (11)C-PiB [100 × ((11)C-PiB SUVR - 1.009)/1.067]. In the young controls, the variance ratio ((18)F-NAV4694 centiloid SD divided by (11)C-PiB centiloid SD) was 0.85.
The results for both (11)C-PiB and (18)F-NAV4694 can now be expressed in centiloids, an important step that should allow better clinical and research use of Aβ imaging. The standard centiloid method also showed that (18)F-NAV4694 has slightly higher Aβ binding and lower variance than (11)C-PiB, important properties for detecting early Aβ deposition and change over time.
对于正电子发射断层扫描（PET）测量β淀粉样蛋白（Aβ）结合情况，在不同示踪剂和方法之间有一个通用的定量输出值，这将有助于更好地比较不同研究地点的数据，并应用通用的诊断和预后值。最近开发了一种方法，可生成一种称为“百剂量单位（centiloid）”的测量单位。我们将此方法应用于2-[2-(18)F-氟-6-(甲氨基)-3-吡啶基]-1-苯并呋喃-5-醇（(18)F-NAV4694）和(11)C-匹兹堡化合物B（(11)C-PiB）的Aβ图像，以得出用百剂量单位表示示踪剂结合所需的比例因子。
55名参与者，包括10名年轻对照者（33±7岁），在不超过3个月的时间内分别接受了(11)C-PiB和(18)F-NAV4694成像，图像在示踪剂注射后50 - 70分钟采集。图像进行空间归一化处理，并使用标准百剂量单位方法以及从全球阿尔茨海默病协会互动网络网站下载的区域（皮质和全小脑参考区域）进行分析。
标准化摄取值比率（SUVRs）在示踪剂结合方面显示出强烈相关性（(18)F-NAV4694 SUVR = 1.09×(11)C-PiB SUVR - 0.08，R² = 0.99）。将(18)F-NAV4694转换为百剂量单位的公式[100×((18)F-NAV4694 SUVR - 1.028)/1.174]与已发表的(11)C-PiB公式[100×((11)C-PiB SUVR - 1.009)/1.067]相似。在年轻对照者中，方差比率（(18)F-NAV4694百剂量单位标准差除以(11)C-PiB百剂量单位标准差）为0.85。
现在(11)C-PiB和(18)F-NAV4694的结果都可以用百剂量单位表示，这是重要的一步，应能使Aβ成像在临床和研究中得到更好的应用。标准百剂量单位方法还表明，与(11)C-PiB相比，(18)F-NAV4694具有稍高的Aβ结合能力和较低的方差，这对于检测早期Aβ沉积及随时间的变化是重要特性。
