Background: Dose calculation algorithms play a very important role in predicting the explicit dose distribution. We evaluated the percent depth dose (PDD), lateral depth dose profile, and surface dose volume histogram in inhomogeneous media using calculation algorithms and inhomogeneity correction methods. Materials and Methods: The homogeneous and inhomogeneous virtual slab phantoms used in th...

Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...

background: broca’s and wernicke’s areas, which are important language areas of brain, are commonly irradiated in patients with right frontal lobe glioblastomamultiforme (gbm). we aimed to compare two different treatment planning techniques in terms of the doses in the broca’s and wernicke’s areas for the patients with right frontal gbm. materials and methods: two different treatment planning t...

introduction accurate estimation of the skin-absorbed dose in external radiation therapy is essential to estimating the probability of secondary carcinogenesis induction materials and methods electron contamination in prostate radiotherapy was investigated using the monte carlo (mc) code calculation. in addition, field size dependence of the skin dose was assessed. excess cancer risk induced by...

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: the electron contamination may reduce or even diminish the skin sparing property of the megavoltage beam. the detailed characteristics of contaminant electrons are presented for different field sizes and cases. materials and methods: the monte carlo code, mcnpx, has been used to simulate 18 mv photon beam from a varian linac-2300 accelerator. all dose measurements were carried out u...

Background: We have validated the monitor unit calculations from a commercially available treatment planning system (TPS) for three intensity modulated radiotherapy (IMRT) planning techniques for tangential breast irradiation by using ionization chamber measurements. Materials and Methods: Treatment plans were generated for forty-two breast patients by a forward planned field in field ...

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...

background: for radiotherapy of total skin including sub-cutaneous tissue up to a depth of 3 cm on the entire left leg of an adult (angiosarcoma skin), a complex treatment with multiple stationary electron fields was planned at our clinic. the details of dosimetry, clinical dose measurements are presented. materials and methods: the treatment planned with 6 overlapping 9 mev electron fields in ...

Background: The aim of this study was to develop and implement a Monte Carlo framework for evaluation of patient specific out-of-field organ equivalent dose (OED). Materials and Methods: Dose calculations were performed using a Monte Carlo-based model of Oncor linac and tomographic phantoms. Monte Carlo simulations were performed using EGSnrc user codes. Dose measurements were performed using r...