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: " Comparison of direct machine parameter optimization versus fluence optimization with sequential sequencing in IMRT of hypopharyngeal carcinoma. | BioMed Central Radiation Oncology Research Open Access Comparison of direct machine parameter optimization versus fluence optimization with sequential sequencing in IMRT of hypopharyngeal carcinoma Barbara Dobler Fabian Pohl Ludwig Bogner and Oliver Koelbl Address Department of Radiotherapy University of Regensburg Regensburg Germany Email Barbara Dobler - Fabian Pohl - Ludwig Bogner - Oliver Koelbl - Corresponding author Published 6 September 2007 Received 3 June 2007 Radiation Oncology 2007 2 33 doi 1748-717X-2-33 Accepted 6 September 2007 This article is available from http content 2 1 33 2007 Dobler 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 To evaluate the effects of direct machine parameter optimization in the treatment planning of intensity-modulated radiation therapy IMRT for hypopharyngeal cancer as compared to subsequent leaf sequencing in Oncentra Masterplan . Methods For 10 hypopharyngeal cancer patients IMRT plans were generated in Oncentra Masterplan Nucletron BV Veenendal the Netherlands for a Siemens Primus linear accelerator. For optimization the dose volume objectives DVO for the planning target volume PTV were set to 53 Gy minimum dose and 59 Gy maximum dose in order to reach a dose of 56 Gy to the average of the PTV. For the parotids a median dose of 22 Gy was allowed and for the spinal cord a maximum dose of 35 Gy. The maximum DVO to the external contour of the patient was set to 59 Gy. The treatment plans were optimized with the direct machine parameter optimization Direct Step Shoot
