SU‐E‐T‐300: Physical Evidence of Gold Nanoparticle Induced Dose Enhancement in Radiotherapy

Purpose: The purpose of this work was to measure gold nanoparticles (AuNPs) induced dose enhancement physically in radiotherapy which has never been verified with experiment although some results in biological experiment indicates that AuNPs can cause the dose enhancement. Methods: Homemade phantom was specially designed to measure dose changes with/without AuNPs and a model GD‐302m glass dosimeter (AGC Techno Glass Corp., Shizuoka, Japan) and FGD‐1000 automatic reader were used to measure absorbed doses. 100‐250 kV x‐ray and 230 MeV proton were irradiated to various sizes of AuNPsResults: Dose enhancement factor (DEF) was 6.24%, 5.54% and 2.30% in 100 kV x‐ray for 10nm, 30nm and 50nm diameter AuNPs, respectively. Dose enhancement factors in 30nm diameter AuNPs for 100 kV x‐ray, 250 kV x‐ray and 230 MeV proton beams were 5.54%, 1.5% and 4.83%, respectively. Conclusion: Our results show that while physical dose enhancement was found with the gold nanoparticles, the quantitative value for DEF depends significantly on size of nanoparticle, energy of radiation, radiation type and etc.