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 between the ...

iran’s industry has had a considerable number of difficulties to perform so well as was expected in the post – revolutionary era. unfavorable legal, political environments combined with eight –year imposed war may be singled out as the root causes of such performances. however, this paper argues that our industry’s lack of realization of its dire need to adapt to the emerging unprecedented envi...

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...

Introduction: Wedge filters are commonly used in radiation oncology for eliminating hot spots and creating a uniform dose distribution in optimizing isodose curves in the target volume for clinical aspects. These are some limited standard physical wedges (15°, 30°, 45°, 60°), or creating an arbitrary wedge angle, like motorized wedge or dynamic wedge, ... The new formulation is...

background: in radiation therapy, the peripheral dose is important when anatomical structures with very low dose tolerances are involved. in this study, the two available calculation algorithms of the varian eclipse 8.6 treatment planning system(tps), the anisotropic analytic algorithm (aaa) and pencil-beam convolution (pbc) was used to compare measured and calculated peripheral dose distributi...

Introduction: Wedge filters are used in radiotherapy to modify photon beam and improve dose uniformity in the target volume. Determination of wedge dose distribution is important to improve treatment planning accuracy. The utilization of treatment planning software to obtain dose distribution is not always available. In this work an analytical model has been developed to calcu...

The purpose of this study was to develop and evaluate filmless quality assurance (QA) tools for helical tomotherapy by using the signals from the on-board megavoltage computed tomography (MVCT) detector and applying a dedicated step-wedge phantom. The step-wedge phantom is a 15 cm long step-like aluminum block positioned on the couch. The phantom was moved through the slit beam and MVCT detecto...

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...