[P093] Long-term quality control and intercomparison results of radionuclide dose calibrators. (August 2018)

• Record Type: Journal Article
• Authors: Skovorodko, Kirill; Gudelis, Arūnas
• Is Part Of: Physica medica. Volume 52(2018)Supplement 1
• Page Start: 127
• Page End: 128
• Publication Date: 2018-08
• Subjects: Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2018.06.413
• Languages: English
• ISSNs: 1120-1797

Abstract

Abstract : Purpose: Nuclear medicine procedure quality is critically dependent on the accuracy of dose calibrators. The aim of this study is to assess the accuracy of measurements of three dose calibrators. For a more accurate evaluation of the measuring equipment, a comparison was done between those dose calibrators and the secondary standard radionuclide calibrator traceable to National metrology institute. Methods: The study was performed with Veenstra VDC-404, Veenstra VDC-405 and PITAGORA dose calibrators in Nuclear medicine department. These dose calibrators were compared with Capintec CRC-15R that was used as a secondary reference standard ionization chamber. This intercomparison was done with 99m Tc, 18 F, 123 I and 137 Cs. For relative response assessment 137 Cs was used as a check source. Linearity checks were fulfilled with 99m Tc for Veenstra VDC-405 and 18 F sources for PITAGORA. Results: The results of the intercomparison show that the uncertainty for Veenstra VDC-404 and Veenstra VDC-405 was 1.5 % at a coverage factor k = 2 when using 99m Tc in both P6 vial and in a 1 ml syringe, while it was 3.5 % ( k = 2 ) for 123 I, and a linearity deviation was less than 3.1 % ( k = 2 ) . The uncertainty for PITAGORA was 0.7 % ( k = 1) when using 18 F in P6 vial, for 137 Cs using P6 vial the geometry factor uncertainty was 0.7 % ( k = 1), the linearity deviation was 2.0 %. Constancy measurements accuracies were within 3 % ( k = 2 ) of the decay-corrected values for all radionuclide dose calibrators. Conclusions: Quality control and intercomparison measurements of dose calibrators are an important part of nuclear medicine quality assurance program. In accordance with international recommendations, our results are within 5–10 % of the recommended values. Daily control with a long half-life check source allows detecting potential failure of the ionization chamber components and enabling the staff to reduce the probability of an incorrect injection of radiopharmaceuticals' activity to the patients. The intercomparisons could identify problems in both calibration and uncertainty evaluation.