A novel application of normoxic polymer gel dosimeters for near real-time dose measurement using cone-beam computed tomography

Abstract The aim of this study is to evaluate the feasibility of using cone-beam CT system as a near real-time measurement device in dose estimation with normoxic polymer gel dosimetry (MAG). Each vial was filled with MAG gel and irradiated with uniform doses of 0–10 Gy to generate dose response curves. After irradiation, a cone-beam CT was used to perform the 3D dose measurement. In this study, two groups of gel samples were irradiated and measured in two ways for comparison: near real-time measurement, in which the gel phantom was read right after the irradiation, and delayed measurement, in which the measurement was performed 30 min, 4 h and 1 day after the irradiation for the gel phantom to be exposed to oxygen. All groups were also performed with and without a full bowtie filter to estimate the influence of a full bowtie filter to dose response. The linear dose response curves with and without a full bowtie filter for the four different CT imaging times were within a range 0.044–0.049Δ N CT  cGy −1 and 0.061–0.063Δ N CT  cGy −1 , respectively, with no significant difference at different imaging times. Nevertheless, dose response curves with the full bowtie filter were higher than those without, with p -value