N-isopropylacrylamide gel dosimeter to evaluate clinical photon beam characteristics

摘要: Abstract The introduction of beam intensity control concept in current radiotherapy techniques has increased treatment planning complexity. Thus, small-field dose measurement become increasingly vital. Polymer gel dosimetry method is widely studied. It the only tool that provides 3D distribution. This study aims to use an N -isopropylacrylamide (NIPAM) dosimeter conduct performance measurements percentage depth (PDD), flatness, and symmetry for photon beams with field sizes 3×3 4×4 cm 2 . Computed tomography scans were used readout dosimeters. In PDD measurement, NIPAM Gafchromic TM EBT3 radiochromic film displayed high consistency region deeper than build-up region. profile had 3% lower flatness at 5 cm different fields compared film. During gamma evaluation under 3%/3 mm difference/distance-to-agreement standard, pass rates polymer TPS both higher 96%. Given tissue equivalent, it did not exhibit energy dependence problems films. Therefore, practical dosimeters enhanced clinical verification.