Verification of micro-beam irradiation

8th International Conference on 3D Radiation Dosimetry

Li, Qiongge^1 ; Juang, Titania^1 ; Beth, Rachel^2 ; Chang, Sha^2,3 ; Oldham, Mark^1

Duke University Medical Center, Durham

NC, United States^1

Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill

NC, United States^2

Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill

NC, United States^3

关键词: Artifact management;    High resolution;    Mechanical motions;    Microbeam irradiation;    Peak-to-valley dose ratios;    Radiation experiment;    Verification method;    Verification process;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/573/1/012047/pdf
DOI  :  10.1088/1742-6596/573/1/012047

来源: IOP

【 摘 要 】

Micro-beam Radiation Therapy (MRT) is an experimental radiation therapy with provocative experimental data indicating potential for improved efficacy in some diseases. Here we demonstrated a comprehensive micro-beam verification method utilizing high resolution (50pm) PRESAGE/Micro-Optical-CT 3D Dosimetry. A small PRESAGE cylindrical dosimeter was irradiated by a novel compact Carbon-Nano-Tube (CNT) field emission based MRT system. The Percentage Depth Dose (PDD), Peak-to-Valley Dose Ratio (PVDR) and beam width (FWHM) data were obtained and analyzed from a three strips radiation experiment. A fast dose drop-off with depth, a preserved beam width with depth (an averaged FWHM across three beams remains constant (405.3um, sigma=13.2um) between depth of 3.0∼14.0mm), and a high PVDR value (increases with depth from 6.3 at 3.0mm depth to 8.6 at 14.0mm depth) were discovered during this verification process. Some operating procedures such as precise dosimeter mounting, robust mechanical motions (especially rotation) and stray-light artifact management were optimized and developed to achieve a more accurate and dosimetric verification method.