Abstract 3193: First Preclinical Study of a New F-18 Labeled PET Tracer for Myocardial Perfusion Imaging

Abstract

Introduction: An F-18 based myocardial perfusion imaging (MPI) tracer would increase the availability of tracers for cardiac PET/CT exams at stand-alone PET facilities. Hypothesis: F-18 labeled BMS-747158 – 02 is a promising tracer for MPI. Methods: All studies were carried out in healthy male Wistar rats (275 ± 25 g). The biodistribution of F-18 BMS-747158 – 02 was obtained 10 and 60 minutes post injection (p.i.). The first pass extraction fraction of the tracer was determined according to the Langendorff method. ECG gated microPET imaging (FOCUS F-120, Siemens Medical Imaging, USA) was performed, and the listmode data were sorted into dynamic sinograms corresponding to the diastolic phase of the heart cycle. After reorientation of the data time activity curves (TACs) were derived for the left ventricular cavity and myocardium, as well as tracer uptake polar maps two minutes p.i.. Rats were measured under MMF anesthesia, either during rest (n = 6) or during adenosine induced stress conditions (n = 6). Tracer retention two minutes p.i. was defined as tracer uptake divided through the integral under the input function. Results: The biodistribution of F-18 BMS-747158 – 02 is favorable for cardiac imaging: high myocardial uptake (3.1 %ID/g) combines with low uptake in lung and liver (0.3 %ID/g and 1.0 %ID/g, respectively, 10 minutes p.i. (n = 3)). The myocardial uptake is homogeneous (the average means equal 77.4 ± 6.0 % and 77.8 ± 7.8 % of the maximum uptake for the rest and stress groups, respectively). The tracer shows a high and flow independent myocardial first pass extraction fraction, averaging 0.94 ± 0.04 (3 flow velocities, n >= 3 per group). Adenosine infusion (140 μg/kg/min) leads to a significant increase in myocardial tracer retention (1.68 ± 0.23 sec −1 to 3.21 ± 0.92 sec −1 ; P = 0.03). Conclusions: F-18 labeled BMS-747158 – 02 shows high extraction combined with excellent imaging characteristics in this first preclinical study of its applicability as a PET MPI agent.