Novel synthesis and initial preclinical evaluation of 18F-[FDG] labeled rhodamine: a potential PET myocardial perfusion imaging agent

•Division of Nuclear Medicine and Molecular Imaging, Boston Children’s Hospital, Boston•Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston•Harvard Medical School, Boston

Myocardial perfusion imaging is one of the most commonly performed investigations in nuclear medicine studies. Due to the clinical importance of [18F]-fluoro-2-deoxy-D-glucose ([18F]-FDG) and its availability in almost every PET center, a new radiofluorinated [18F]-FDG-rhodamine conjugate was synthesized using [18F]-FDG as a prosthetic group. In a convenient and simple one-step radiosynthesis, [18F]-FDG-rhodamine conjugate was prepared in quantitative radiochemical yields, with total synthesis time of nearly 20 min and radiochemical purity of greater than 98%, without the need for HPLC purification, which make these approaches amenable for automation. Biodistribution studies in normal rats at 60 min post-injection demonstrated a high uptake in the heart (> 11% ID/g) and favorable pharmacokinetics. Additionally, [18F]-FDG-rhodamine showed an extraction value of 27.63% ± 5.12% in rat hearts. These results demonstrate that [18F]-FDG-rhodamine conjugate may be useful as an imaging agent for the positron emission tomography evaluation of myocardial perfusion.