Prog Med Phys.  2014 Sep;25(3):123-127. 10.14316/pmp.2014.25.3.123.

Determination of TRS-398 Quality Factors for Cs-137 Gamma Rays in Reference Dosimetry

• Kang SK
• Rhee DJ
• Kang YR
• Kim JK
• Jeong DH

• KMID: 1910543
• DOI: http://doi.org/10.14316/pmp.2014.25.3.123

Abstract

The Cs-137 irradiator is widely used to irradiate biological samples for radiobiological research. To obtain the accurate outcomes, correct measurements of the delivered absorbed dose to a sample is important. The IAEA protocols such as TRS-277 and TRS-398 were recommended for the Cs-137 reference dosimetry. However in TRS-398 protocol, currently known as the most practical dosimetry protocol, the quality factor (k(Q,Q0)) for Cs-137 gamma rays is not suggested. Therefore, the use of TRS-398 protocol is currently unavailable for the Cs-137 dosimetry directly. The calculation method previously introduced for high energy photon beams in radiotherapy was used for deriving the Cs-137 beam qualities (k(Q,Q0)) for the 15 commercially available farmer type ionization chambers in this study. In conclusion, k(Q,Q0) values were ranged from 0.998 to 1.002 for Cs-137 gamma rays. These results can be used as the reference and dosimeter calibrations for Cs-137 gamma rays in the future radiobiological researches.

Keyword

Cs-137 gamma rays; TRS-398 protocol; Quality factor

MeSH Terms

Calibration
Gamma Rays*
Radiotherapy

Figure

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  Fig. 1. Quality factors including Cs-137 gamma rays determined in this study. The quality factor for Cs-137 is slightly higher than that of Co-60 gamma rays.

Reference

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