Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo khoa học: "Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization"

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: Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization. | Two-step intensity modulated arc therapy 2-step IMAT with segment weight and width optimization Sun et al. Sun et al. Radiation Oncology 2011 6 57 http www.ro-journal.Com content 6 1 57 2 June 2011 BioMed Central Sun et al. Radiation Oncology 2011 6 57 http www.ro-journal.eom content 6 1 57 RESEARCH RADIATION ONCOLOGY Open Access Two-step intensity modulated arc therapy 2-step IMAT with segment weight and width optimization Jidi Sun1t Theam Yong Chew2t and Juergen Meyer1 t Abstract Background 2-step intensity modulated arc therapy IMAT is a simplified IMAT technique which delivers the treatment over typically two continuous gantry rotations. The aim of this work was to implement the technique into a computerized treatment planning system and to develop an approach to optimize the segment weights and widths. Methods 2-step IMAT was implemented into the Prism treatment planning system. A graphical user interface was developed to generate the plan segments automatically based on the anatomy in the beam s-eye-view. The segment weights and widths of 2-step IMAT plans were subsequently determined in Matlab using a dose-volume based optimization process. The implementation was tested on a geometric phantom with a horseshoe shaped target volume and then applied to a clinical paraspinal tumour case. Results The phantom study verified the correctness of the implementation and showed a considerable improvement over a non-modulated arc. Further improvements in the target dose uniformity after the optimization of 2-step IMAT plans were observed for both the phantom and clinical cases. For the clinical case optimizing the segment weights and widths reduced the maximum dose from 114 of the prescribed dose to 107 and increased the minimum dose from 87 to 97 . This resulted in an improvement in the homogeneity index of the target dose for the clinical case from 1.31 to 1.11. Additionally the high dose volume V105 was reduced from 57 to 7 while the maximum dose in the organ-at-risk