Whole-Body Biodistribution and Radiation Dosimetry of the New Cardiac Tracer 99mTc-N-DBODC
Corrado Cittanti 1,
Licia Uccelli 1,
Micol Pasquali 1,
Alessandra Boschi 1,
Claudia Flammia 1,
Elisa Bagatin 1,
Massimiliano Casali 1,
Michael G. Stabin 2,
Luciano Feggi 3,
Melchiore Giganti 1,
and
Adriano Duatti 1*
1 Laboratory of Nuclear Medicine and Nuclear Medicine Section, Department of Radiological Sciences, University of Ferrara, Ferrara, Italy
2 Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee
3 Nuclear Medicine Unit, Department of Diagnostic Imaging and Laboratory Medicine, S. Anna University Hospital, Ferrara, Italy
* To whom correspondence should be addressed. E-mail: dta{at}unife.it.
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Abstract |
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Our purpose was to evaluate the safety profile and biodistribution behavior in healthy human volunteers of the new myocardial perfusion tracer bis[(dimethoxypropylphosphanyl)ethyl]ethoxyethylamine N,N'-bis(ethoxyethyl)dithiocarbamato nitrido technetium(V) (99mTc-N-DBODC). Methods: Ten healthy male volunteers were injected with 99mTc-N-DBODC under both stress and rest conditions. Anterior and posterior planar 
-camera images were collected at 5, 30, 60, 240, and 1,440 min after injection, with organ uptake quantified by region-of-interest analysis. Tracer kinetics in body fluids were determined by collecting blood and urine samples at different time points. Results: After injection, 99mTc-N-DBODC showed significant accumulation in the myocardium and prolonged retention. Under rest conditions, uptake in the heart, lungs, and liver at 5 min after injection was 1.67% ± 0.13%, 1.16% ± 0.07%, and 10.85% ± 1.72%, respectively, of administered activity. Under stress conditions, heart uptake was significantly higher (2.07% ± 0.22%). Radioactivity in the liver decreased to 3.64% ± 0.98% and 2.37% ± 0.48% at 60 and 240 min, respectively, after injection. This rapid liver clearance led to favorable heart-to-liver ratios, reaching values of 0.74 ± 0.13 at rest and 1.26 ± 0.28 during exercise 60 min after tracer administration. Radiation dose estimates were comparable to those obtained with other myocardial perfusion cationic compounds. Conclusion: The high uptake in the myocardium and the fast liver washout of 99mTc-N-DBODC will allow SPECT images of the left ventricle to be acquired early and with excellent quality.
Key Words:
cardiac perfusion imaging, monocationic complexes, nitrido complexes, 99mTc
