Earticle

초록

영어

Background: A NaI(Tl) survey meter was used in the pediatric thyroid screening conducted after the Fukushima Daiichi Nuclear Power Plant accident. However, this measurement method has the weakness that it is difficult to selectively identify 131I. In this study, we analyzed the performance of an energy-analyzable NaI(Tl) spectrometer using the Particle and Heavy Ion Transport code System (PHITS), which allows Monte Carlo simulation of radiation transport. Materials and Methods: The spectrum of energy emitted by the NaI(Tl) spectrometer was simulated for a total energy absorption peak by adjusting factors that affect pulse wave height. From these simulation results, the detection limits of the NaI(Tl) spectrometer were obtained using Monte Carlo simulation. Results and Discussion: The energy spectrum results were reproduced with an accuracy of 0.1% to 44.0% for total energy absorption peaks. The calculated detection limit for 131I activity equivalent to 100 mSv in the thyroid under a 0.2 μSv· hr−1 ambient dose rate was approximately 80–90 Bq, which could be detected for up to 38 days after 131I intake in a 1-year-old child. Conclusion: This study demonstrated that pediatric thyroid screening using an NaI(Tl) spectrometer can practically provide greater accuracy than NaI(Tl) survey meters.

목차

ABSTRACT
Introduction
Materials and Methods
1. Simulation of the 131I Energy Spectrum
2. Calculation of the NaI(Tl) Spectrometer Detection Limit
3. Calculation of the Number of Detectable Days for 131I Accumulated in the Thyroid Gland
4. Verification of the Effects of 132Te, a Short-Lived Radionuclide
Results
1. Verification of Agreement between Experimental Results and Monte Carlo Simulations
2. Energy Spectrum of 131I Reproduced Using the PHITS
3. Experimentally Determined Detection Limits of the NaI(Tl) Spectrometer
4. Calculation of Thyroid Uptake, Residual Thyroid Radioactivity, and the Number of Measurable Days
5. Effect of the Short-Lived Nuclide 132Te on the Energy Spectrum
Discussion
1. Agreement between Experimental Values and Monte Carlo Simulations
2. Reproduction of the 131I Energy Spectrum
3. Detection Limit of a NaI(Tl) Spectrometer
4. Calculation of Days Available for Measurement of Residual Thyroid Radioactivity
5. Effect of the Short-Lived Nuclide 132Te on Measurements
6. Comparison of NaI(Tl) Scintillation Survey Meters and NaI(Tl) Spectrometers
7. Limitations of the Study and Future Prospects
Conclusion
Conflict of Interest
Ethical Statement
Author Contribution
References

키워드

저자

• Takahiro Kitajima [ Department of Radiology, Nippon Bunri University Medical College, Oita, Japan ] Corresponding Author
• Mitsuaki Ojima [ Oita University Graduate School of Nursing and Health Sciences, Oita, Japan ]
• Yoshimitsu Shinagawa [ Oita University Graduate School of Nursing and Health Sciences, Oita, Japan ]
• Michiaki Kai [ Department of Health Sciences, Nippon Bunri University, Oita, Japan ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  방사선방어학회지 [Journal of Radiation Protection and Research]

• 간기

  계간

• pISSN

  2508-1888

• 수록기간

  1976~2026

• 등재여부

  KCI 등재,SCOPUS

• 십진분류

  KDC 559 DDC 629