background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

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This study proposes an algorithm for selecting beam weight, wedge angle, and wedge orientation for three-dimensional radiation therapy treatment planning. According to dose gradient analysis, the necessary and sufficient condition for achieving a homogeneous dose over the target volume is that the total vector sum of the dose gradients of all beams be zero everywhere in the target volume. This ...

BACKGROUND The aim of the modern radiotherapy is to get a homogenous dose distribution in PTV, which is obtained by using for example physical or dynamic wedges. The using of a physical wedge has provided such isodose distributions but their use resulted in detrimental dosimetric consequences, for example beam hardening effects and practical consequences of filter handling or possible misalignm...

BACKGROUND Theoretical considerations suggest that leg length increases after opening wedge high tibial osteotomy (HTO) and decreases after closing wedge HTO; however, in vivo studies have yielded conflicting results. This meta-analysis therefore assessed changes in leg length after opening wedge and closing wedge HTO. METHODS All studies comparing pre- and postoperative leg length in patient...

background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

background: considering suggested formula in the references and pcwp measured by catheterism, in the present study the relation between pulmonary capillary wedge pressure (pcwp) measured the flow velocity of mitral valve and mitral annulus motion through tissue doppler imaging is evaluated methods: 52 cases of severe ms were admitted for balloon mitral valvolotomy (bmv) are included in this stu...

in this research, numerical simulation of a symmetric impact of a 2-d wedge, considering dynamic equations in two-phase flow is taken into account. the two-phase flow around the wedge is solved based on finite volume method and volume of fluid (vof) scheme. the dynamic mesh model is used to simulate dynamic motion of the wedge, thereby the effects of different dynamic meshes in both structured ...

A new method of generating wedge-shaped dose distributions through dynamic multileaf collimator dose delivery rather than computer-controlled jaw motion is presented. The method starts with the calculation of a wedge-shaped beam profile for the desired wedge angle. The resultant wedge beam profile is then passed to the intensity-modulated radiation therapy (IMRT) leaf sequence generation algori...

High tibial osteotomy (HTO) has been widely used for clinical treatment of osteoarthritis of the medial compartment of the knee, and both opening-wedge and closing-wedge HTO are the most commonly used methods. However, it remains unclear which technique has better clinical and radiological outcomes in practice. To systematically evaluate this issue, we conducted a comprehensive meta-analysis by...