Browsing by Author "Zheng, YM"

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    Novel 99mTc(III)-azide complexes [99mTc(N3)(CDO)(CDOH)2B-R] (CDOH2 = cyclohexanedione dioxime) as potential radiotracers for heart imaging
    Liu, M; Zheng, YM; Avcibasi, U; Liu, S
    Introduction: In this study, novel Tc-99m(III)-azide complexes [Tc-99m(N-3)(CDO)(CDOH)(2)B-R] (Tc-99m-ISboroxime-N-3: R = IS; Tc-99m-MPboroxime-N-3: R = MP; Tc-99m-PAboroxime-N-3: R = PA; Tc-99m-PYboroxime-N-3: R = PY; and Tc-99m-Uboroxime-N-3: R = 5U) were evaluated as heart imaging agents. Methods: Complexes [Tc-99m(N-3)(CDO)(CDOH)(2)B-R] (R = IS, MP, PA, PY and 5U) were prepared by ligand exchange between NaN3 and [(TcCl)-Tc-99m(CDO)(CDOH)(2)B-R]. Biodistribution and imaging studies were carried out in Sprague-Dawley rats. Image quantification was performed to compare their initial heart uptake and myocardial retention. Results: Tc-99m-ISboroxime-N-3, Tc-99m-PYboroxime-N-3 and Tc-99m-Uboroxime-N-3 were prepared with high RCP (93-98%) while the RCP of Tc-99m-MPboroxime-N-3 and Tc-99m-PAboroxime-N-3 was 80-85%. The myocardial retention curves of Tc-99m-ISboroxime-N-3, Tc-99m-PYboroxime-N-3 and Tc-99m-Uboroxime-N-3 were best fitted to the bi-exponential decay function. The half-time of the fast component was 1.6 +/- 0.4 min for Tc-99m-ISboroxime-N-3, 0.7 +/- 0.1 min for Tc-99m-PYboroxime-N-3 and 0.9 +/- 0.4 min for Tc-99m-Uboroxime-N-3. The 2 min heart uptake from biodistribution studies followed the ranking order of Tc-99m-ISboroxime-N-3 (3.60 0.68%ID/g) > Tc-99m-PYboroxime-N-3 (2.35 0.37%ID/g) Tc-99m-Uboroxime-N-3 (1.29 0.06%ID/g). Tc-99m-ISboroxime-N-3 had the highest 2-min heart uptake among Tc-99m radiotracers revaluated in SD rats. High quality SPECT images were obtained with the right and left ventricular walls being clearly delineated. The best image acquisition window was 0-5 min for Tc-99m-ISboroxime-N-3. Conclusion: Both azide coligand and boronate caps had significant impact on the heart uptake and myocardial retention of complexes [Tc-99m(N-3)(CDO)(CDOH)(2)B-R]. Among the radiotracers evaluated in SD rats, Tc-99m-ISboroxime-N-3 has the highest initial heart uptake with the heart retention comparable to that of Tc-99m-Teboroxime. Tc-99m-ISboroxime-N-3 is a promising alternative to Tc-99m-Teboroxime for SPECT MPI. (C) 2016 Elsevier Inc. All rights reserved.