Room: AAPM ePoster Library
Three-dimensional dose distribution, tissue equivalent, high spatial resolution, low energy and dose dependency are the significant characteristics of gel dosimeters over conventional dosimeters.
The aim of this study was to compare the radiation sensitivity between Platinum nanoparticles (PtNPs) and Gadolinium oxide nanoparticles (GdNPs), through the use of 18 MV photon beam via measuring dose enhancement factor (DEF) using MR-based MAGICA polymer gel dosimeter.
The MAGICA polymer gel was first prepared in laboratory, then PtNPs and GdNPs, with average diametesr of 30-50 nm and 36 nm, respectively, were embedded in MAGICA gel vials and then irradiated with 18 MV photon beams. These vials were imaged by 1.5T MRI Simence scanner using head coil, 24 hours after irradiation.
The result shows up to 2 Gy dose irradiation, the DEF value for PtNPs and GdNPs were 6% and 8%, respectively. However, for 3 to 5 Gy dose irradiation, while the amount of DEF of GdNPs remained almost stable to 8%, but for PtNPs increased considerably to 11% at 5Gy in concentrations of 0.1 mM,
The results showed that owing the higher amount of DEF in PtNPs relative to GdNPs up to 11%, as well as, due to its higher atomic number of 78 than that of GdNPs (64), therefore, PtNPs is more sensible to conclude that using MAGICA with PtNPs for clinical purpose would be more effective at high energy application of 18 MV.