RT Journal Article
SR Electronic
T1 <sup>99m</sup>Tc(CO)<sub>3</sub>(NTA): A <sup>99m</sup>Tc Renal Tracer with Pharmacokinetic Properties Comparable to Those of <sup>131</sup>I-OIH in Healthy Volunteers
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 391
OP 396
DO 10.2967/jnumed.109.070813
VO 51
IS 3
A1 Andrew T. Taylor
A1 Malgorzata Lipowska
A1 Luigi G. Marzilli
YR 2010
UL http://jnm.snmjournals.org/content/51/3/391.abstract
AB Studies in rats showed that the pharmacokinetics of the tricarbonyl core radiopharmaceutical 99mTc(CO)3-nitrilotriacetic acid, 99mTc(CO)3(NTA), were essentially identical to those of 131I ortho-iodohippuran (131I-OIH), the clinical gold standard for the measurement of effective renal plasma flow. Our objective was to compare the pharmacokinetics of these 2 tracers in healthy volunteers. Methods: 99mTc(CO)3(NTA) was prepared with commercially available NTA and a commercially available kit and isolated by reversed-phase high-performance liquid chromatography. Approximately 74 MBq (2 mCi) of 99mTc(CO)3(NTA) were coinjected with 9.25 MBq (250 μCi) of 131I-OIH in 9 volunteers, and simultaneous imaging of each tracer was performed for 24 min. Plasma clearances were determined from 8 blood samples obtained 3–90 min after injection using the single-injection, 2-compartment model. Plasma protein binding, red cell uptake, and percentage injected dose in the urine at 30 and 180 min were determined. Results: There was no difference in the plasma clearances of 99mTc(CO)3(NTA) and 131I-OIH, 475 ± 105 mL/min versus 472 ± 108 mL/min, respectively. The plasma protein binding and red cell uptake of 99mTc(CO)3(NTA) were 43% ± 5% and 9% ± 6%, respectively; both values were significantly lower (P &lt; 0.001) than the plasma protein binding (75% ± 3%) and red cell uptake (17% ± 5%) of 131I-OIH. There was no significant difference in the percentage injected dose recovered in the urine at 30 min and at 3 h; for comparison, the percentage dose in the urine at 3 h was 91% ± 4% for 99mTc(CO)3(NTA) and 91% ± 6% for 131I-OIH (P = 0.96). Image quality with 99mTc(CO)3(NTA) was excellent, and the renogram parameters were similar to those of 131I-OIH. Conclusion: Preliminary results in healthy volunteers suggest that the pharmacokinetic behavior of 99mTc(CO)3(NTA) is comparable to that of 131I-OIH.