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...

To evaluate the influence of mid treatment hemoglobin level with the other prognostic factors on the outcome in patients with TisT1N0 glottic carcinoma treated with radiotherapy (RT). Between October 1995 and December 2008, a total of 84 patients diagnosed with Tis-T1N0 glottic carcinoma were treated with definitive RT. The influence of tumor, treatment, and patient-related factors on local con...

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...

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...

HALLDAL[l] describes the use of an interference-wedge filter as a simple monochromator for recording different types of spectra. His use of the cam and screen to obtain equal quanta is particularly clever. We have used interference-wedge filters in a similar way for the purpose of recording fluorescence emission spectra[2,3]. I t is frequently useful and efficient to be able to change the scann...

Terrestrial laser scanning is of increasing importance for surveying and hazard assessments. Digital terrain models are generated using the resultant data to analyze surface processes. In order to determine the terrain surface as precisely as possible, it is often necessary to filter out points that do not represent the terrain surface. Examples are vegetation, vehicles, and animals. Filtering ...

introduction wedge modifiers are commonly applied in external beam radiotherapy to change the dose distribution corresponding to the body contour and to obtain a uniform dose distribution within the target volume. since the radiation dose delivered to the target must be within ±5% of the prescribed dose, accurate dose calculation by a treatment planning system (tps) is important. the objective ...

In this paper, we review most major filtering approaches to texture feature extraction and perform a comparative study. Filtering approaches included are Laws masks, ring/wedge filters, dyadic Gabor filter banks, wavelet transforms, wavelet packets and wavelet frames, quadrature mirror filters, discrete cosine transform, eigenfilters, optimized Gabor filters, linear predictors, and optimized fi...