PURPOSE This study aims to retrospectively evaluate dosimetric parameters calculated as biological effective dose in relation to outcome in patients with cervical cancer treated with various treatment approaches, including radiotherapy with and without surgery. MATERIAL AND METHODS Calculations of biological effective dose (BED) were performed on data from a retrospective analysis of 171 pati...

Background: This study aimed to evaluate the dose calculation accuracy of EclipseTM treatment planning system (TPS) in a heterogeneous chest phantom with the intensity modulated radiotherapy (IMRT) technique using EBT3 film and Delta4. Materials and Methods: Two IMRT plans (A and B) were prepared for radiotherapy of the heterogeneous chest phantom. Plan A was between the left lung and the surro...

introduction radiotherapy with small fields is used widely in newly developed techniques. additionally, dose calculation accuracy of treatment planning systems in small fields plays a crucial role in treatment outcome. in the present study, dose calculation accuracy of two commercial treatment planning systems was evaluated against monte carlo method. materials and methods siemens once or linea...

background: absolute dosimetry of external beam radiotherapy is carried out by the use of ionization chambers. these chambers must be calibrated at a standard dosimetry laboratory before any use in clinical dosimetry. the secondary standard dosimetry laboratory of iran (ssdl) has the duty of calibrating the ionization chambers used in radiotherapy centers in iran. materials and methods: the pre...

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...

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 ...

An essential component in proton radiotherapy is the algorithm to calculate the radiation dose to be delivered to the patient. The most common dose algorithms are fast but they are approximate analytical approaches. However their level of accuracy is not always satisfactory, especially for heterogeneous anatomical areas, like the thorax. Monte Carlo techniques provide superior accuracy; however...

objective: the aim of this study is to evaluate the effect of tissue composition on dose distribution in electron beam radiotherapy. methods : a siemens primus linear accelerator and a phantom were simulated using mcnpx monte carlo code. in a homogeneous cylindrical phantom, six types of soft tissue and three types of tissue-equivalent materials were investigated. the tissues included muscle (s...

background: because of the adverse effects of ionizing radiation on fetuses, prior to radiotherapy of pregnant patients, fetal dose should be estimated. fetal dose has been studied by several authors in different depths in phantoms with various abdomen thicknesses (at). in this study, the effect of maternal at and depth in fetal dosimetry was investigated, using peripheral dose (pd) distributio...