Novel Fluorine-18 Labeled Rhodamine Derivatives For Myocardial Perfusion Imaging With Positron Emission Tomography
Inventors: Alan Packard, Carmen Solorzano, S. Treves, Tobias Heinrich
Categories: Diagnostic/Prognostic, Research Tool
SubCategories: Cardiovascular/Cardiology, Radiology
Keywords: Composition of Matter
The inventors describe novel fluorine-18 labeled rhodamine derivatives for use in PET for diagnostic evaluation of myocardial perfusion. Myocardial perfusion imaging provides functional imaging for the diagnosis and assessment of ischemic heart disease. Damaged myocardium receives lower blood perfusion than the unaffected tissues and can be imaged with radiocompounds that target the myocardial tissue. Radiologic imaging in cardiac stress tests is preferential to echocardiography, with higher specificity and sensitivity of diagnosis and better ability to localize affected regions. Most nuclear cardiac stress tests use Tc99m-labeled imaging reagents and detection by single photon emission computed tomography (SPECT) imaging. Positron emission tomography (PET)-based myocardial perfusion imaging provides functional images of high quality that can be co-registered with images of metabolic activity.
Myocardial perfusion imaging is useful in the diagnosis of cardiac disease. PET-based myocardial perfusion imaging provides functional images of high quality that can be co-registered with [18F] fluoro-deoxy-glucose images to delineate regions of infarct and ischemia.
Short-lived compounds such as [15O]H2O, [13N]NH3, and 82Rb are well established myocardial perfusion imaging tracers; however, there are challenges to the production and distribution of these compounds. For example, PET centers without a cyclotron are limited to using 82Rb, which has significant limitations including high cost and high positron energy. The development of an 18F myocardial perfusion tracer that could be distributed from central radiopharmacies would obviate these limitations. The one-pot labeling procedure described in this invention is fast (the two steps require only 45 min.) and provides a high overall yield (35-6%). The radiochemical purity after solid phase extraction is greater than 90%.
Key Publications: 1. Synthesis and initial in vivo characterization of 18F-labeled rhodamine B: A potential PET myocardial perfusion agent. T. Heinrich, F. Fahey, P. Dunning, E.Snay, S.T. Treves and A. Packard. J Nucl Med. 2008; 49 (Supplement 1):302P.
2. Biodistribution and stability studies of [18F]fluoroethylrhodamine B, a potential PET myocardial perfusion agent. Gottumukkala V, Heinrich TK, Baker A, Dunning P, Fahey FH, Treves ST, Packard AB. Nucl Med Biol. 2010 Apr;37(3):365-70. doi: 10.1016/j.nucmedbio. 2009. 12.005. Epub 2010 Feb 10.
IPStatus: Pat. Pend.