Monte Carlo investigation of energy response of various detector materials in I125 and Yb169 brachytherapy dosimetry

摘要

Relative absorbed‐dose energy response correction R for different detector materials in water, PMMA and polystyrene phantoms are calculated using Monte Carlo‐based EGSnrc code system for I125 and Yb169 brachytherapy sources. The values of R obtained for I125 source are 1.41, 0.92, 3.97, 0.47, 8.32 and 1.10, respectively, for detector materials LiF, Li2B4O7,  Al2O3, diamond, silicon diode and air. These values are insensitive to source‐to‐detector distance and phantom material. For Yb169 source, R is sensitive to source‐to‐detector distance for detector materials other than air and Li2B4O7. For silicon, R increases from 3 to 4.23 when depth in water is increased from 0.5 cm to 15 cm. For Yb169 source, the values of R obtained for air and Li2B4O7 in PMMA and polystyrene phantoms are comparable to that obtained in water. However, LiF, Si and Al2O3 show enhanced response and diamond shows decreased response in PMMA and polystyrene phantoms than in water.PACS number: 87.53.Jw