RT Journal Article SR Electronic T1 Glycoprotein IIb/IIIa Receptor Imaging with 18F-GP1 PET for Acute Venous Thromboembolism: An Open-Label, Nonrandomized, Phase 1 Study JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 244 OP 249 DO 10.2967/jnumed.118.212084 VO 60 IS 2 A1 Chanwoo Kim A1 Jae Seung Lee A1 Youngjin Han A1 Sun Young Chae A1 Soyoung Jin A1 Changhwan Sung A1 Hye Joo Son A1 Seung Jun Oh A1 Sang Ju Lee A1 Jungsu S. Oh A1 Yong-Pil Cho A1 Tae-Won Kwon A1 Deok Hee Lee A1 Seongsoo Jang A1 Bohyun Kim A1 Norman Koglin A1 Mathias Berndt A1 Andrew W. Stephens A1 Dae Hyuk Moon YR 2019 UL http://jnm.snmjournals.org/content/60/2/244.abstract AB 18F-GP1 is a derivative of elarofiban with a high affinity to activated platelet glycoprotein IIb/IIIa and favorable in vivo characteristics for thrombus imaging in preclinical models. We aimed to explore the detection rate of thromboembolic foci with 18F-GP1 PET/CT in patients with acute venous thromboembolism and to evaluate the safety, biodistribution, pharmacokinetics, and metabolism of 18F-GP1. Methods: We studied patients who had signs or symptoms of acute deep-vein thrombosis (DVT) of the leg or acute pulmonary embolism (PE) within 14 d before 18F-GP1 PET/CT and had thromboembolic foci confirmed by conventional imaging (n = 10 for DVT and n = 10 for PE). Dynamic whole-body PET/CT images were acquired for up to 140 min after injection of 250 MBq of 18F-GP1. Results: 18F-GP1 PET/CT was well tolerated, without any drug-related adverse events, and showed high initial uptake in the spleen, kidneys, and blood pool, followed by rapid clearance. The overall image quality was excellent and allowed interpretation in all patients. 18F-GP1 PET/CT identified thromboembolic foci in all 20 patients with either DVT or PE. Vessel-level analysis revealed that 18F-GP1 PET/CT detected 89% (68/76) of vessels with DVT and 60% (146/245) with PE. Importantly, 18F-GP1 PET/CT showed increased uptake in 32 vessels that were not detected by conventional imaging, of which 25 were located in distal veins of the lower extremity in 12 patients. A positive correlation was found between 18F-GP1 uptake and P-selectin–positive circulating platelets (r = 0.656, P = 0.002). Conclusion: 18F-GP1 is a promising PET tracer for imaging acute venous thromboembolism in patients. 18F-GP1 PET/CT may identify thrombi in distal veins of the leg, where conventional imaging has limitations.