Biodistribution, dosimetry, and safety of myocardial perfusion imaging agent (TcN)-Tc-99m-NOET in healthy volunteers

(TcN)-Tc-99m-NOET (bis[N-ethoxy,N-ethyl]dithiocarbamato nitrido technetium (V)) has been proposed for myocardial perfusion imaging. Biodistribution, s afety, and dosimetry were studied in 10 healthy volunteers (5 at rest and 5 during exercise). Methods: Biodistribution was studied by acquiring dynami c images up to 60 min after injection and whole-body images up to 24 h afte r injection. The MIRDOSE3 analysis program was used for radiation dosimetry calculations. Results: Safety parameters measured to 48 h after injection revealed no clinically significant changes. Cardiac uptake of (TcN)-Tc-99m- NOET was high (2.9%3%), With biologic half-life of 210-257 min on average. Lung uptake of (TcN)-Tc-99m-NOET was higher (10%-20%) but, on average, biol ogic half-life was shorter (1-77 min). Clearance from the blood was rapid ( 5% by 5 min). Radiation dosimetry calculations indicated an effective absor bed dose of 5.11 X 10(-3) mSv/MBq at rest and 5.38 X 10(-3) mSv/MBq after e xercise. Conclusion: (TcN)-Tc-99m-NOET exhibits high cardiac uptake and an estimated effective absorbed dose comparable with that of the other Tc-99m- labeled compounds used in myocardial perfusion imaging.