title: Assessment of human effective absorbed dose of 67 Ga-ECC based on biodistribution rat data.
abstract: OBJECTIVE
  In a diagnostic context, determination of absorbed dose is required before the introduction of a new radiopharmaceutical to the market to obtain marketing authorization from the relevant agencies. In this work, the absorbed dose of [67 Ga]-ethylenecysteamine cysteine [(67 Ga)ECC] to human organs was determined by using distribution data for rats.
  
  
  METHODS
  For biodistribution data, the animals were sacrificed by CO2 asphyxiation at selected times after injection (0.5, 2 and 48 h, n = 3 for each time interval), then the tissue (blood, heart, lung, brain, intestine, feces, skin, stomach, kidneys, liver, muscle and bone) were removed. The absorbed dose was determined by Medical Internal Radiation Dose (MIRD) method after calculating cumulated activities in each organ.
  
  
  RESULTS
  Our prediction shows that a 185-MBq injection of (67)Ga-ECC into the humans might result in an estimated absorbed dose of 0.029 mGy in the whole body. The highest absorbed doses are observed in the spleen and liver with 33.766 and 16.847 mGy, respectively.
  
  
  CONCLUSIONS
  The results show that this radiopharmaceutical can be a good SPECT tracer since it can be produced easily and also the absorbed dose in each organ is less than permitted absorbed dose.
authors.affiliation: Radiation Application Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Shanehsazzadeh
authors.forename: Hassan
authors.initials: H
authors.lastname: Yousefnia
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Lahooti
authors.forename: Samaneh
authors.initials: S
authors.lastname: Zolghadri
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Jalilian
authors.forename: Hossien
authors.initials: H
authors.lastname: Afarideh
mesh_terms: D000818:Animals; D056831:Coordination Complexes / Q000493:pharmacokinetics*; D003545:Cysteine / Q000493:pharmacokinetics*; D006801:Humans; D011829:Radiation Dosage; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
chemical_list: C000602457:67Ga-ethylenecysteamine cysteine; D056831:Coordination Complexes; D003545:Cysteine