title: [Quality control of dose calibrator using a traceable syringe-type (68)Ge/(68)Ga calibration source].
abstract: OBJECTIVE
  Accurate calibration of dose calibrators (DC) is required for quantitative positron emission tomography (PET) studies to generate meaningful information. Values measured by DC depend not only on the radioactive nuclide but also the environment where measurements are taken. Therefore, DC must be calibrated at each location. The present study aimed to determine appropriate calibration values, and evaluate the performance of DC using a traceable (68)Ge/(68)Ga calibration source that is available as a surrogate (18)F source.
  
  
  METHODS
  We used a (68)Ge/(68)Ga calibration source to determine the optimal DC value for measuring (18)F activity in the operating environment. Variations in sensitivity and geometry as well as measurement uncertainty were evaluated using the (68)Ge/(68)Ga source. We adopted the criteria of the Guide for the expression of uncertainty in measurement (GUM) to evaluate DC performance.
  
  
  RESULTS
  Although the manufacturer's recommended (18)F calibration number for the CRC-25PET is 480, we found that the optimal number was 482. Over a period of one year, the sensitivity of the DC varied <0.1%, and the expanded uncertainty of DC measurements was 2.2%.
  
  
  CONCLUSIONS
  Measurements of the certified activity of a traceable national standard were corrected, and the uncertainty of measurements as well as the accuracy of a DC were determined. Calibration numbers for DC should be regularly determined using (68)Ge/(68)Ga calibration sources at each location to ensure the most accurate results.
authors.affiliation: Department of Nuclear Medicine, Cancer Institute Hospital of Japanese Foundation for Cancer Research.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Miyaji
authors.forename: Kenta
authors.initials: K
authors.lastname: Miwa
authors.forename: Kei
authors.initials: K
authors.lastname: Wagatsuma
authors.forename: Takuro
authors.initials: T
authors.lastname: Umeda
authors.forename: Taisuke
authors.initials: T
authors.lastname: Murata
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Takiguchi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Koizumi
mesh_terms: D002138:Calibration / Q000592:standards*; D005710:Gallium Radioisotopes; D005857:Germanium; D049268:Positron-Emission Tomography; D011786:Quality Control; D011868:Radioisotopes; D012680:Sensitivity and Specificity
chemical_list: D005710:Gallium Radioisotopes; D011868:Radioisotopes; D005857:Germanium