Novel high resolution I-125 brachytherapy source dosimetry using Ge-doped optical fibres

作者：Issa Fatma^*; Hugtenburg Richard P; Ni**et Andrew; Bradley David A

来源：Radiation Physics and Chemistry, 2013, 92: 48-53.

DOI：10.1016/j.radphyschem.2013.06.005

• Optical fibres
• I-125 seed
• Brachytherapy
• Dosimetry
• Dose measurements
• Monte Carlo simulation

The steep dose gradients close to brachytherapy sources limit the ability to obtain accurate measurements of dose. Here we use a novel high spatial resolution dosimeter to measure dose around a I-125 source and compare against simulations. Ge-doped optical fibres, used as thermoluminescent dosimeters, offer sub-mm spatial resolution, linear response from 10 cGy to %26gt; 1 kGy and dose-rate independence. %26lt;br%26gt;For a I-125 brachytherapy seed in a PMMA phantom, doses were obtained for source-dosimeter separations from 0.1 cm up to several cm, supported by EGSnrc/DOSRZznrc Monte Carlo simulations and treatment planning system data. The measurements agree with simulations to within 23% +/- 0.3% along the transverse and perpendicular axes and within 3.0% +/- 0.5% for measurements investigating anisotropy in angular dose distribution. Measured and Veriseedrm brachytherapy treatment planning system (TPS) values agreed to within 2.7% +/- 0.5%. %26lt;br%26gt;Ge-doped optical fibre dosimeters allow detailed dose mapping around brachytherapy sources, not least in situations of high dose gradient.

• 出版日期2013-11