title: Estimated human absorbed dose for (68)Ga-ECC based on mice data: comparison with (67)Ga-ECC.
abstract: OBJECTIVE
  Nowadays, the efficacies of (68)Ga-based tracers are comparable to that of (18)F-based agents and have stimulated researchers to investigate the potential of (68)Ga-based positron emission tomography (PET) imaging agents. In this study, the human absorbed dose of (68)Ga labeled with ethylenecysteamine cysteine (68)Ga-ECC and (67)Ga-ECC was estimated based on biodistribution data in mice by the medical internal radiation dose (MIRD) method.
  
  
  METHODS
  For biodistribution of (67)Ga/(68)Ga-ECC, three mice were killed by CO2 asphyxiation at each selected times after injection (15, 30, 45, 60, 120 min for (68)Ga-ECC and 0.5, 2 and 48 h for (67)Ga-ECC), and then the tissue (heart, lung, brain, intestine, skin, stomach, kidneys, liver, muscle and bone) was removed.
  
  
  RESULTS
  (68)Ga-ECC as a new PET renal imaging agent was prepared with radiochemical purity of >97 % in less than 30 min. The biodistribution data for (68)Ga-ECC showed that the most of the activity extracted from the urinary tract very fast. Comparison between human absorbed dose estimation for these two agents indicated that the absorbed dose of the most organs after injection of (67)Ga-ECC is approximately tenfold higher than the amount after (68)Ga-ECC injection.
  
  
  CONCLUSIONS
  The results showed that (68)Ga-ECC is a more appropriate agent rather than (67)Ga-ECC and generally can be a good candidate for PET renal imaging applications.
authors.affiliation: Nuclear Science and Technology Research Institute (NSTRI), 14155-1339, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Shanehsazzadeh
authors.forename: Hassan
authors.initials: H
authors.lastname: Yousefnia
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Jalilian
authors.forename: Samaneh
authors.initials: S
authors.lastname: Zolghadri
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Lahooti
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism / Q000528:radiation effects; D001921:Brain / Q000378:metabolism / Q000528:radiation effects; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000493:pharmacokinetics; D005710:Gallium Radioisotopes / Q000493:pharmacokinetics; D005753:Gastric Mucosa / Q000378:metabolism; D006321:Heart / Q000528:radiation effects; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000528:radiation effects; D007668:Kidney / Q000378:metabolism / Q000528:radiation effects; D008099:Liver / Q000378:metabolism / Q000528:radiation effects; D008168:Lung / Q000378:metabolism / Q000528:radiation effects; D008297:Male; D051379:Mice; D009132:Muscles / Q000378:metabolism / Q000528:radiation effects; D049268:Positron-Emission Tomography; D011829:Radiation Dosage; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D012867:Skin / Q000378:metabolism / Q000528:radiation effects; D013270:Stomach / Q000528:radiation effects
chemical_list: C000602457:67Ga-ethylenecysteamine cysteine; D056831:Coordination Complexes; D005710:Gallium Radioisotopes; D019275:Radiopharmaceuticals