title: [Evaluation of Measurement Accuracy and Inter-institutional Comparison for Dose Calibrators].
abstract: OBJECTIVE
  The aim of this study was to validate the reliability of dose calibrators for measuring the radioactivity of several radioisotopes in multi-institution.
  
  
  METHODS
  We evaluated the measurement accuracy of dose calibrators using a commercially available source ((67) Ga, (99m) Tc, (123) I, (201) TL). Nine dose calibrators (five models) in seven institutions were performed in this study. Each source was measured at least 3 times a day over a period of 4 half-life. Linearity of concentration (%error value) and percent difference values (%diff measurement) between measured and estimated radioactivity were calculated to evaluate the measurement accuracy. In addition, difference among institutions (%diff institution) was evaluated by the error values between measured and reference institution values.
  
  
  RESULTS
  Good linearity of concentration was found between measured and estimated radioactivity in (99m)Tc and (123)I. However, %error value was increased in (67)Ga and (201)TL (maximum 19.3%). %diff measurements were 1.9 ± 0.3% for (67)Ga, -0.9 ± 0.3% for (99m)Tc, 2.2 ± 0.4% for (123)I, and -0.7 ± 0.3% for (201)TL, respectively. Although there were no clear differences in six institutions, %diff institution in one institution tended to be higher than that obtained in other institutions.
  
  
  CONCLUSIONS
  Our results indicated that measurement accuracy of nine dose calibrators (five models) was relatively stable. However, difference of measured values tended to be higher in a part of institution and source. It is important to perform quality assurance and quality control for dose calibrator using traceable source.
authors.affiliation: Department of Radiological Technology, Kurashiki Central Hospital (Current address: Department of Medical Radiological Technology, Faculty of Health Sciences, Kyorin University).
authors.forename: Norikazu
authors.initials: N
authors.lastname: Matsutomo
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kangai
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yada
authors.forename: Syuuji
authors.initials: S
authors.lastname: Kenda
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kai
authors.forename: Yukito
authors.initials: Y
authors.lastname: Maeda
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sakai
authors.forename: Hideo
authors.initials: H
authors.lastname: Onishi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
mesh_terms: D002138:Calibration / Q000592:standards*; D011786:Quality Control; D011829:Radiation Dosage; D011868:Radioisotopes
chemical_list: D011868:Radioisotopes