A Validation Study on Radiation properties of a Novel LiF: Mg, Ti Known as IAP-100

Document Type : Original Paper

Authors

1 Malekashtar University,Tehran, Iran

2 Medical Physics Dept, Faculty of Medicine, Mashhad University of Medical Sciences

3 Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

4 Energy Engeineering and physics faculty, Amirkabir University of Technology, Tehran, Iran

5 Medical Physics Department, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

Abstract

Introduction: LiF dosimeter has the most application in medicine. This study aimed to evaluate some dosimetric properties of a novel LiF: Mg, Ti.
Materials and Methods: An ELEKTA Precise linear accelerator was used to calibrate dosimeters at 6 MV. In this survey, responses of dosimeters were evaluated up to 1000 cGy. Background effect was investigated in two different dosimeter states including irradiated and unirradiated.Thermoluminescence response dependence to dose rate was investigated, as well. Energy dependence was evaluated in diagnostic and therapeutic ranges. Furthermore, fading effect was evaluated by reading the dosimeters every 2 h up to 12 h post-irradiation.
 Results: The dosimeters had linear response up to 250 cGy. Readout values of dosimeters receiving 120 cGy at three dose rates of 21, 212, 425 cGy.min-1 were calculated equal to 125, 123, 121 cGy, respectively. The measured values of delivering 80, 120, and 150 cGy prescribed doses at 6 MV, 10 MV, and 15 MV were accurate at 6 MV and about 1.5 times higher than the prescribed doses at 10 and 15 MV. Thermoluminescence response in diagnostic energy range showed an uprising trend with increasing energy.
Conclusion: The raising thermoluminescence response with increasing energy contradicts with the findings of Nunn. Due to the reproducibility and linear response of dosimeters in an acceptable dose range, they could be used in diagnostic and therapeutic fields. Effects of absorbed doses from background in low-dose studies, mainly in diagnostic radiology range, could be evaluated in more detail in future surveys.

Keywords

Main Subjects


  1. References

     

    1. Kron T. Applications of thermoluminescence dosimetry in medicine. Radiation protection dosimetry. 1999;85(1-4):333-40. DOI: 10.1093/oxfordjournals.rpd.a032865.
    2. Furetta C. Handbook of thermoluminescence: World Scientific; 2010.
    3. Davis S, Ross C, Mobit P, Van der Zwan L, Chase W, Shortt K. The response of lif thermoluminescence dosemeters to photon beams in the energy range from 30 kV x rays to 60Co gamma rays. Radiation protection dosimetry. 2002;106(1):33-43. DOI: 10.1093/oxfordjournals.rpd.a006332.
    4. Khan FM, Gibbson JP. The Physics Of RAdiation Therapy. 1984 s, 1993 n, 2003 t, 2010 t, editors. China2014.
    5. Pereira J, Pereira MF, Rangel S, Saraiva M, Santos LM, Cardoso JV, et al. Fading Effect of LiF:Mg,Ti and LiF:Mg,Cu,P Ext-Rad and Whole-body Detectors. Radiat Prot Dosimetry. 2016;170(1-4):177-80. DOI: 10.1093/rpd/ncv445.
    6. Horowitz Y, Oster L, Datz H. The thermoluminescence dose–response and other characteristics of the high-temperature TL in LiF: Mg, Ti (TLD-100). Radiation protection dosimetry. 2007. DOI: 10.1093/rpd/ncm241.
    7. Romanyukha A, King D, Benevides LA. Effect of background radiation on the lower limit of detection for extended dosemeter issue periods. Radiat Prot Dosimetry. 2008;131(2):180-7. DOI: 10.1093/rpd/ncn137.
    8. Chen R, Leung P. A model for dose-rate dependence of thermoluminescence intensity. Journal of Physics D: Applied Physics. 2000;33(7):846.
    9. Wrobel F, Benabdesselam M, Iacconi P, Mady F. Kerma rate effects on thermoluminescent response of CVD diamond. Radiat Prot Dosimetry. 2006;119(1-4):115-8. DOI: 10.1093/rpd/nci585.
    10. Benabdesselam M, Iacconi P, Butler J, Nigoul J. TL characterisation of a CVD diamond wafer for ionising radiation dosimetry. Diamond and related materials. 2003;12(10):1750-4. DOI: 10.1016/S0925-9635(03)00195-X.
    11. Development of Procedures for In Vivo Dosimetry in Radiotherapy. Austria; 2013. IAEA human health reports, ISSN 2074–7667 .
    12. Nunn AA, Davis SD, Micka JA, DeWerd LA. LiF:Mg,Ti TLD response as a function of photon energy for moderately filtered x-ray spectra in the range of 20-250 kVp relative to 60Co. Med Phys. 2008;35(5):1859-69. DOI: 10.1118/1.2898137.