Tetrofosmin

Fig. 17. Tc02 complex with(l,2-bis(bis-ethoxyethyl)phos-phino)ethane (Tc-Tetrofosmin) [123, 124]...

Fig. 4. Lipophilic-cationic( +1) myocardial perfusion imaging agents A) 99mTc-tetrofosmin R = -CH2CH,0CH,CH3 B), 9"Tc = sestamibi R=C=NCH,C (OCHJ (CH,), Q 99mTc-furifosmin R = -CH2CH2OCH2CH3...

Figure 7.12 (A) 99mTc-sestamibi (Cardiolite ) and (B) "mTc-tetrofosmin (Myoview ).

Myoview 99mTc-tetrofosmin (67) is another clinically approved, lipophilic, cationic perfusion agent (286). The molecule contains trans-... 

Fukuzawa S, Inagaki M, Morooka S, Inoue T, Matsumoto Y, Yokoyama K et al. Evaluation of myocardial viability using sequential dual-isotope single photon emission tomography imaging with rest TI-201 / stress Tc-99m tetrofosmin in the prediction of wall motion recovery after revascularization. Jpn Circ J 1997 61 481 87... 

I. Madar, H. Ravert, A. Dipaula, Y. Du, R.F. Dannals, L. Becker, Assessment of severity of coronary artery stenosis in a canine model using the PET agent F-fluorobenzyl triphenyl phosphonium Comparison with " Tc-tetrofosmin, J. Nucl. Med. 48 (2007) 1021-1030. 

Transient myocardial ischemia was evaluated in 112 patients undergoing the Bruce protocol exercise stress testing. Technetium tetrofosmin scans were obtained and BNP levels were assessed before, during, and four hours after exercise (13). If patients had no inducible ischemia, BNP levels were low at baseline, 43 pg/mL, and unchanged during and after exercise. However, in patients with inducible ischemia, BNP levels rose from a median 62 to 92 pg/mL and nearly returned to baseline at four hours postexercise, Patients with severe ischemia had median BNP levels at baseline, 101 pg/mL and increased to 123 pg/mL, These were still elevated four hours postexercise to I 15 pg/mL, Differences were based on the BNP levels, Patients with no ischemia (43 pg/mL), mild to moderate ischemia (60-92 pg/mL), and severe ischemia (101 pg/mL) were statistically different, These differences were increased with exercise stress (13),... 

Fig. 14 Time variation of a heart/lung and b heart/liver ratios for the complexes 99mTcN-DBODC (squares), 99mTc-Sestamibi (circles) and 99mTc-Tetrofosmin (triangles) measured at a specific time after injection in rats. The values are expressed as the ratio between the activity localized in the heart and the activity localized in the lungs and the liver, respectively...

Other lipophilic cations that have been approved as myocardial perfusion agents include a Tc(III) Tc-teboroxime cryptate, (Cardiotec ), the trans-dioxo technetium(V) bis-phosphine complex, "Tc-tetrofosmin (Myoview ) and the mixed ligand Tc(III) Schiff-base bisphosphine Tc-Q12 complex, Tc-furifosmin (TechneScan) (Figure 3). 

Technetium Tc 99m tetrofosmin injection, 2004, in United States Pharmacopeia, 27th rev., and National Formulary, 22nd ed., The United States Pharmacopeial Convention, Inc., Rockville, MD, p. 1783. 

Myoview is a TcOj complex, obtained by functional derivatization of l,2-bis(dimethylpho-sphino)ethane (DMPE) (Kelly et al. 1993). The chemical structure of Tc-tetrofosmin shows four phosphorus atoms of the bidentate diphosphine ligands, arranged in a plane (Fig. 2.1.11). However, tetrofosmin contains four ethoxyethyl groups, which ensure a rapid clearance of activity from the liver. The cationic charge facilitates myocardial uptake. 

Trans-octahedral configuration of the donor atoms has been confirmed by x-ray single crystal analysis of the Tc analog. The HPLC behavior is the same for the Tc and Tc tetrofosmin complex (Kelly et al. 1993). 

Kelly JD, Forster AM, Higley B, Archer CM, Booker FS, Caiming LR, Chiu KW, Edwards B, Gill HK, McPartlin M, Nagle KR, Latham I A, Pickett RD, Storey AE, Webbon PM (1993) Techne-tium-99m-tetrofosmin as a new radiopharmaceutical for myocardial perfusion imaging. J Nucl... 

Among the neutron-deficient isotopes of Tc, " Tc seems to have suitable nuclear properties for application in positron emission tomography (PET) (Browne and Firestone 1986). Considering the relatively new lipophilic Tc-labeled flow tracers used in cardiac perfusion imaging (2-methoxyisobutyl isocyanide [MlBl], teboroxime, tetrofosmin) it would be reasonable to replace Tc with " Tc in order to carry out quantitative investigations of biodistribution and clearance with PET. With this replacement, the pharmacokinetics of useful Tc compounds could be studied in a number of cases, which would enhance the introduction of new Tc-labeled pharmaceuticals into clinical practice. The labeling and quality control methods are well known and partly subject of this book. Our task is to review the different methods for the production of Tc and also the separation technique from irradiated targets. 

Tc(V) dioxo diphosphine complex 99rnTc tetrofosmin injection... 

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