Advertisement

Nuclear Medicine and Molecular Imaging

, Volume 52, Issue 3, pp 234–237 | Cite as

Survey Result of the Counting Efficiency of Gamma Counter by Certified Reference Materials

  • Ji-In Bang
  • Ho-Young Lee
  • Geyoung Woon Noh
  • Jeong Mi Park
  • June Kee Yoon
Original Article
  • 55 Downloads

Abstract

Purpose

In radioimmunoassay (RIA), the gamma counter is the important instrument for the accurate measurement. To manage quality assurance of RIA, the counting efficiency of gamma counter is one of the important parameters. The aim of this study was to evaluate the counting efficiency of gamma counters in multiple institutes on the base of traceability by using the certified reference materials (CRMs).

Methods

Twenty-three institutes that perform RIA were enrolled in this study. I-125 CRMs that were certified by National Institute of Standards and Technology (NIST) were used. Each institute was asked to count the activity of I-125 CRMs at most twice on all gamma counters in use. The counting efficiency of each well of counter was calculated on the base of NIST-certified information, corrected for I-125 decay for date of testing.

Results

From 23 institutes, 44 gamma counters were evaluated. The average counting efficiency of all wells was 85.9% and the standard deviation was 13.5%. As a mean value of each gamma counter, three gamma counters showed poor counting efficiency (less than 70%). The poorest counting efficiency was 7%. The counting efficiency of seven gamma counters was between 70 and 75%. Eight counters had the counting efficiency between 75 and 90%. More than half of counter (26 gamma counters) showed excellent counting efficiency (more than 90%). The standard deviation variation range of inter-well efficiency was from 0 to 11.2.

Conclusion

The first survey on the counting efficiency of gamma counter was performed in South Korea. Most of the RIA laboratories have well managed the quality assurance of gamma counter.

Keywords

Radioimmunoassay Immunoradiometric assay Efficiency Quality control 

Notes

Funding

This work was supported by the Technology Innovation Program (10053674) funded by the Ministry of Trade, Industry and Energy (MOTIE, Korea).

Compliance with Ethical Standards

Conflict of Interest

Ho-Young Lee, Ji-In Bang, Geyoung Woon Noh, Jeong Mi Park, and June Kee Yoon declare that they have no conflict of interest.

Ethical Approval

All procedures performed in study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed Consent

All procedures performed in study involved the medical device, and the requirement to obtain informed consent was waived.

References

  1. 1.
    Yalow RS, Berson SA. Immunoassay of endogenous plasma insulin in man. J Clin Invest. 1960;39:1157–75.CrossRefPubMedPubMedCentralGoogle Scholar
  2. 2.
    Zaidi P, Kamal S. Radioimmunoassay: principle and technique. J Pak Med Assoc. 1993;43:264.PubMedGoogle Scholar
  3. 3.
    Lee JM, Lee HH, Park S, Kim TS, Kim S-K. Random assay in radioimmunoassay: feasibility and application compared with batch assay. Nucl Med Mol Imaging. 2016;50:337–43.CrossRefPubMedPubMedCentralGoogle Scholar
  4. 4.
    Lodge MA, Holt DP, Kinahan PE, Wong DF, Wahl RL. Performance assessment of a NaI (Tl) gamma counter for PET applications with methods for improved quantitative accuracy and greater standardization. EJNMMI physics. 2015;2:11.CrossRefPubMedPubMedCentralGoogle Scholar
  5. 5.
    ISO I. 15189: 2012 Medical laboratories–requirements for quality and competence. Geneva: International Standardisation Organisation. 2012.Google Scholar
  6. 6.
    AD MN, Wilkinson A. Compendium of chemical terminology: IUPAC. Oxford: Blackwell Science; 1997.Google Scholar
  7. 7.
    Bales ZB, Patterson JF, Hoofnagle JH, Seeff LB. Variation in gamma counter efficiency used in radioimmunoassay testing for hepatitis B surface antigen and antibody. Transfusion. 1978;18:91–3.CrossRefPubMedGoogle Scholar
  8. 8.
    Chambron J. Quantitative analysis in imaging and function.Google Scholar
  9. 9.
    De Bièvre P, Günzler H. Traceability in chemical measurement. Springer; 2005.Google Scholar

Copyright information

© Korean Society of Nuclear Medicine 2018

Authors and Affiliations

  • Ji-In Bang
    • 1
  • Ho-Young Lee
    • 1
  • Geyoung Woon Noh
    • 2
  • Jeong Mi Park
    • 4
  • June Kee Yoon
    • 3
  1. 1.Department of Nuclear MedicineSeoul National University Bundang HospitalSeongnam-siSouth Korea
  2. 2.Department of Nuclear MedicineSeoul National University HospitalSeoulSouth Korea
  3. 3.Department of Nuclear MedicineAjou University HospitalSuwonSouth Korea
  4. 4.Department of Nuclear MedicineSoonchunhyang Bucheon University HospitalBucheonSouth Korea

Personalised recommendations