نتایج جستجو برای: tangential breast technique
تعداد نتایج: 857112 فیلتر نتایج به سال:
introduction: the complex geometry of breast and also lung and heart inhomogeneities near the planning target volume (ptv) result in perturbations in dose distribution. this problem can result in overdosage or underdosage in the match region of the three treatment fields. the purpose of this study is to create a homogeneous dose distribution in the match region between the supraclavicular and t...
breast conservation surgery combined with radiation therapy is now an accepted option for the treatment of early breast cancer. so we decided to evaluate the results of such treatment in our first group of patients treated by this method. from 1992 to 1996 , one hundred patients with stage i and ii breast cancer treated with breast conservative surgery (lumpectomy or quadrantectomy). were irrad...
AIMS External beam radiotherapy is being used regularly to treat the breast malignancy postoperatively. The contribution of collimator leakage and scatter radiation dose to contralateral breast is of concern because of high radio sensitivity of breast tissue for carcinogenesis. This becomes more important when the treated cancer breast patient is younger than 45 years and therefore the contrala...
background : this study was set to determine the optimal technique of breast cancer with supraclavicular fossa irradiation. methods : three techniques was compared in this study. techniques were two point symmetric (2p-sym), two point asymmetric (2p-asym) and single point (sp). in 2p-sym all of beams were symmetric, in 2p-asym tangential beams were symmetric and supra was asymmetric, in sp all ...
BACKGROUND AND PURPOSE The optimal intensity fluence profile of a beam depends on the profiles of other beams but most optimizations assume fixed beam orientations, a priori. Breast cancer radiotherapy attempts to cover the target and to spare critical structures such as the heart and lungs. The study aims are (1) to determine and document the optimal two-beam orientation that best spares the h...
The general solution of the equations for a homogeneous isotropic microstretch thermo elastic medium with mass diffusion for two dimensional problems is obtained due to normal and tangential forces. The Integral transform technique is used to obtain the components of displacements, microrotation, stress and mass concentration, temperature change and mass concentration. A particular case of inte...
INTRODUCTION The magnitude of intra- and inter-fractional variation in the set up of breast cancer patients treated with tangential megavoltage photon beams was investigated using an electronic portal imaging device (EPID). METHODS Daily cine-EPID images were captured during delivery of the tangential fields for ten breast cancer patients treated in the supine position. Measurements collected...
Background: During breast three fields radiotherapy, the problem is that the divergency of the field interferes with matching the edges. So the matching point of these supraclav and tangential field will suffer from over-dose and under-dose. To prevent these these divergency, a half- block is often applied at supracluv field. Also in some techniques like collimator and couch rotation, corner bl...
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