Comparison of the BANGkitTM and the PRESAGETM Gel Dosimeters for Use with a CCD-based Optical CT Scanner

We compared the basic characteristics of two commercially-available scattering gel (BANGkitTM)and non-scattering gel (PRESAGETM) dosimeters with a spectrophotometer to investigate each device’sdosimetric properties. The two types of gel dosimeters were spectrophotometrically analyzed. For each gel dosimeter, the absorbance, dose linearity, reproducibility, dose rate dependency, andoxygen effect were evaluated at various wavelengths and doses. The best dose linearities of theBANGkitTM and the PRESAGETM gel dosimeters gave R2 values of 0.97 and 0.98 at wavelengthsof 485 nm and 600 nm, respectively, over the range of doses. The BANGkitTM gel showed no peaksensitivity within the studied range of wavelengths whereas the PRESAGETM gel demonstratedpeak sensitivity at a wavelength of 630 nm. The reproducibilities and the dose-rate dependencesof the two gel dosimeters were within the range of ± 2% and ± 3%, respectively. We have shownthat the peak sensitivities of the two gel dosimeters were significantly different; the BANGkitTMgel showed no peak sensitivity within the studied range of wavelengths whereas the PRESAGETMgel demonstrated a peak sensitivity at a wavelength of 630 nm. We have confirmed that the radiochromicgel dosimeter was appropriate for use with a CCD-based optical CT scanner. KCI Citation Count: 3