Wiwat Youngdee

Publications (2)3.37 Total impact

• Article: Monte Carlo simulation of average glandular dose and an investigation of influencing factors.

  Khatayut Nigapruke, Patana Puwanich, Nakorn Phaisangittisakul, Wiwat Youngdee
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  ABSTRACT: This study aims to determine the average absorbed dose of radiation in glandular tissue during mammography and to investigate factors that influence the average glandular dose, particularly the local distribution of glandular tissue within the breast and breast skin thickness. An EGSnrc Monte Carlo code and associated codes were employed in the simulation. The breast voxel models used consist of a homogeneous and heterogeneous mixture of adipose and glandular tissues embedded in a skin layer. The percent depth dose and normalized average glandular dose coefficients for spectra of Mo-Mo target-filter combination were calculated. The results showed good agreement with the experimental results (percent depth dose) and literature values (normalized average glandular dose coefficients) when the breast model is homogeneous. Additional investigation of a heterogeneous breast phantom indicates that the local distribution of glandular tissue within the breast, as well as breast skin thickness, could affect the average glandular dose considerably more than that of a typical homogeneous breast model. This problem may be a concern in most practical situations of breast dosimetry when assessing the radiation risk to patients.
  Journal of Radiation Research 01/2010; 51(4):441-8. · 1.68 Impact Factor
• Article: A comparison of mammographic x-ray spectra: simulation with EGSnrc and experiment with CdTe detector.

  Khatayut Nigapruke, Patana Puwanich, Nakorn Phaisangittisakul, Wiwat Youngdee
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  ABSTRACT: Mammographic x-ray spectra simulated by BEAMnrc/EGSnrc Monte Carlo code were qualitatively compared with the results obtained from the direct measurement using a cadmium telluride x-ray spectroscopy system and from the generation of IPEM report number 78. Generally, there is good agreement between the simulated and measured spectra, though there are slight differences at low energy in which the K-characteristic x-ray intensity is relatively higher for IPEM spectra. In addition, transmission curves were measured and simulated using a breast tissue-equivalent phantom (BR-12) as filtration. Comparison of the transmission curves shows good agreement. Moreover, the first half value layer (HVL) from direct measurement using ion chamber was consistent with the first HVL calculated by simulated spectra. Therefore, Monte Carlo may be used as an alternative tool for obtaining x-ray spectra when direct measurement is not available.
  Journal of Radiation Research 09/2009; 50(6):507-12. · 1.68 Impact Factor