A universal wedge filter of 15W × 20 cm(2) and 60° nominal wedge angle is designed and placed between the collimating jaws and penumbra trimmers inside the treatment head. A pneumatically driven actuating mechanism toggles the wedge between the wedge IN position and wedge OUT position. The effective wedge angles were determined using an analytical formula. An accumulated wedge profile at a dept...

introduction: nowadays,  considerable developments  in  the field  of  radiotherapy have  been  achieved.  they  include  the  advances  made  in  the  equipments  and  treatment  planning  techniques  which  require  highly complex calculations. such achievements have made it possible to treat cancer patients not only  with  higher  radiation  dose  but  also  with  higher  precision  and  con...

background: in radiotherapy, wedge filters are used for optimizing the tumor dose distribution in patients. the attenuation in beam intensity due to the presence of wedge filter is compensated by means of a wedge factor measured at the central axis of the beam. the field size, depth and ssd dependence of wedge factor have been assessed for 9mv radiations of neptun pc linear accelerator. materia...

Interfacial fluctuation effects occuring at wedge and cone filling transitions are investigated and shown to exhibit very different characteristics. For both geometries we show how the conditions for observing critical (continuous) filling are much less restrictive than for critical wetting, which is known to require fine tuning of the Hamaker constants. Wedge filling is critical if the wetting...

Introduction: Nowadays,  considerable developments  in  the field  of  radiotherapy have  been  achieved.  They  include  the  advances  made  in  the  equipments  and  treatment  planning  techniques  which  require  highly complex calculations. Such achievements have made it possible to treat cancer patients not only  with  higher  radiation  dose  but  also  with  higher  precision  and  con...

A comprehensive theory of interfacial fluctuation effects occurring at 2D wedge (corner) filling transitions in pure (thermal disorder) and impure (random bond-disorder) systems is presented. Scaling theory and the explicit results of transfer matrix and replica trick studies of interfacial Hamiltonian models reveal that, for almost all examples of intermolecular forces, the critical behaviour ...

Background: The presence of a wedge filter in the beam trajectory can modify the beam quality and cause some changes in the dosimetry parameters which are usually difficult to be measured directly and accurately. Material and Methods: In this study the MCNP-4C Monte Carlo code was used to simulate the 9 MV photon beam generated by a linear accelerator. Upon getting a good agreement bet...

Background: It was intended to investigate the effect of physical wedge (PW) and enhanced dynamic wedges (EDW) on contralateral breast dose during primary breast irradiation in radiotherapy treatment, using high energy photon beams. Materials and Methods: The Varian’s Clinac dual mode linear accelerator model 2100 C/D and Siemen’s Primus accelerators were used for radiation doses wi...

Background: The radiation dose received by contralateral breast (CLB) is one of the concerns of breast radiotherapy, because it may lead to the induction of secondary breast cancer. The aim of this study was to evaluate the CLB surface dose in the breast treatment in Yazd radiotherapy center. Materials and Methods: The surface dose of CLB was measured using TLD dosimetry in 50 cancer breast pat...