tailieunhanh - Báo cáo khoa học: " Verifying 4D gated radiotherapy using time-integrated electronic portal imaging: a phantom and clinical study"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài:" Verifying 4D gated radiotherapy using time-integrated electronic portal imaging: a phantom and clinical study. | Radiation Oncology BioMed Central Research Verifying 4D gated radiotherapy using time-integrated electronic portal imaging a phantom and clinical study John R van Sornsen de Koste Johan P Cuijpers Frank GM de Geest Frank J Lagerwaard Ben J Slotman and Suresh Senan Open Access Address Department of Radiation Oncology VU University medical center Amsterdam The Netherlands Email John R van Sornsen de Koste - Johan P Cuijpers - Frank GM de Geest - Frank J Lagerwaard - Ben J Slotman - Suresh Senan - Corresponding author Published 30 August 2007 Received 3 May 2007 Radiation Oncology 2007 2 32 doi 1748-717X-2-32 Accepted 30 August 2007 This article is available from http content 2 1 32 2007 van Sornsen de Koste et al licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Respiration-gated radiotherapy RGRT can decrease treatment toxicity by allowing for smaller treatment volumes for mobile tumors. RGRT is commonly performed using external surrogates of tumor motion. We describe the use of time-integrated electronic portal imaging TI-EPI to verify the position of internal structures during RGRT delivery Methods TI-EPI portals were generated by continuously collecting exit dose data aSi500 EPID Portal vision Varian Medical Systems when a respiratory motion phantom was irradiated during expiration inspiration and free breathing phases. RGRT was delivered using the Varian RPM system and grey value profile plots over a fixed trajectory were used to study object positions. Time-related positional information was derived by subtracting grey values from TI-EPI portals sharing .