放射線治療領域の線量測定におけるポリマーゲル線量計の有用性の評価 Investigations on the Performance of Polymer Gel Dosimeter for Radiation Therapy
Gel dosimeters are sensitive chemical dosimeters that aim at measuring the dose in three dimensions(3D). This study aims to evaluate the performance of a commercially available BANG<SUP>®</SUP> polymer gel. BANG<SUP>®</SUP> gels were irradiated using 6MV photon beams from 0.5Gy to 60Gy. The magnetic resonance(MR)spin-spin relaxation rate(R<SUB>2</SUB>=1/T<SUB>2</SUB>) of the protons indicates dose response and has a linear relationship to dose. The dose response curve by BANG<SUP>®</SUP> gel appeared approximately linear over the 0.5Gy and 20Gy region. The slope of the dose-R<SUB>2</SUB> curve is 0.9s<SUP>−1</SUP>Gy<SUP>−1</SUP>, and the relative dose distribution can be reproduced with an overall uncertainty of about 2%. R<SUB>2</SUB> was found to increase with increasing time after irradiation. BANG<SUP>®</SUP> gels are of comparable quality to MOSFET or PLD in terms of overall dosimetric accuracy and have the advantage of measuring continuous, cumulative 3D dose distributions.
Radioisotopes 57(3), 183-188, 2008-03-15
Japan Radioisotope Association