Laboratory of Radiopharmacy, Faculty of Pharmaceutical Sciences, Gent University, Harelbekestraat 72, 9000, Ghent, Belgium.
EJNMMI Res. 2013 Sep 14;3(1):66. doi: 10.1186/2191-219X-3-66.
Until now, no kinetic model was described for the oncologic tracer [18F]fluoromethylcholine ([18F]FCho), so it was aimed to validate a proper model, which is easy to implement and allows tracer quantification in tissues.
Based on the metabolic profile, two types of compartmental models were evaluated. One is a 3C2i model, which contains three tissue compartments and two input functions and corrects for possible [18F]fluorobetaine ([18F]FBet) uptake by the tissues. On the other hand, a two-tissue-compartment model (2C1i) was evaluated. Moreover, a comparison, based on intra-observer variability, was made between kinetic modelling and graphical analysis.
Determination of the [18F]FCho-to-[18F]FBet uptake ratios in tissues and evaluation of the fitting of both kinetic models indicated that corrections for [18F]FBet uptake are not mandatory. In addition, [18F]FCho uptake is well described by the 2C1i model and by graphical analysis by means of the Patlak plot.
The Patlak plot is a reliable, precise, and robust method to quantify [18F]FCho uptake independent of scan time or plasma clearance. In addition, it is easily implemented, even under non-equilibrium conditions and without creating additional errors.
到目前为止，尚未有针对肿瘤示踪剂[18F]氟甲基胆碱([18F]FCho)的动力学模型进行描述，因此，本研究旨在验证一种合适的模型，该模型易于实施，并能实现组织中示踪剂的定量。
基于代谢谱，评估了两种类型的室模型。一种是包含三个组织室和两个输入函数的 3C2i 模型，可纠正组织中可能的[18F]氟硼酸([18F]FBet)摄取。另一方面，评估了双室模型(2C1i)。此外，基于观察者内变异性，比较了动力学建模和图形分析。
测定组织中[18F]FCho 与[18F]FBet 的摄取比，并评估两种动力学模型的拟合度，结果表明，[18F]FBet 摄取的校正并非必需。此外，2C1i 模型和 Patlak 图的图形分析都能很好地描述[18F]FCho 的摄取。
Patlak 图是一种可靠、精确且强大的方法，可独立于扫描时间或血浆清除率来定量[18F]FCho 的摄取。此外，它易于实施，即使在非平衡条件下，也无需引入额外的误差。
