tailieunhanh - Báo cáo y học: "Monte Carlo Commissioning of Low Energy Electron Radiotherapy Beams using NXEGS Software"

Tuyển tập các báo cáo nghiên cứu khoa học ngành y học tạp chí Medical Sciences dành cho các bạn sinh viên ngành y tham khảo đề tài: Monte Carlo Commissioning of Low Energy Electron Radiotherapy Beams using NXEGS Software. | Int. J. Med. Sci. 2004 1 2 63-75 63 Research paper Received Accepted Published Abstract Key words Author biography Corresponding address International Journal of Medical Sciences ISSN 1449-1907 2004 Ivyspring International Publisher. All rights reserved Monte Carlo Commissioning of Low Energy Electron Radiotherapy Beams using NXEGS Software Joseph A. Both Todd Pawlicki Department of Radiation Oncology Stanford University School of Medicine Stanford CA 94305 USA This work is a report on the commissioning of low energy electron beams of a medical linear accelerator for Monte Carlo dose calculation using NXEGS software NXEGS version NX Medical Software LLC . A unique feature of NXEGS is automated commissioning a process whereby a combination of analytic and Monte Carlo methods generates beam models from dosimetric data collected in a water phantom. This study uses NXEGS to commission 6 9 and 12 MeV electron beams of a Varian Clinac 2100C using three applicators with standard inserts. Central axis depth-dose primary axis and diagonal beam profiles and output factors are the measurements necessary for commissioning of the code. We present a comparison of measured dose distributions with the distributions generated by NXEGS using confidence limits on seven measures of error. We find that confidence limits are typically less than 3 or 3 mm but increase with increasing source to surface distance SSD and depth at or beyond R50. We also investigate the dependence of NXEGS performance on the size and composition of data used to commission the program finding a weak dependence on number of dose profiles in the data set but finding also that commissioning data need be measured at only two SSDs. Monte Carlo electron beam commissioning NXEGS Joseph Both . is a postdoctoral fellow in the physics division of the Department of Radiation Oncology at Stanford University School of Medicine. His research interests include .