objective(s): in this study we evaluate the impact of the different aspects of gold nano-particles (gnps) on the target absorptive dose enhancement factor (def) during external targeted radiotherapy with photon beams ranging from kilovolt to megavolt energies using monte carlo simulation. methods: we have simulated the interaction of photon beams with various energies of radiation using water s...

BACKGROUND MRI-only radiotherapy will eliminate the systematic registration errors introduced when transferring MRI information to the CT. However, challenges concerning the missing information on electron density, necessary for dose calculation and patient setup on bony anatomy are introduced. This study presents a possible statistical approach to evaluate, if deviations based on MRI-only radi...

Background: Craniospinal radiotherapy faces technical challenges which are due to the sensitivity of the location in which the gross tumor is, and to organs at risk around planning target volume. Using modern treatment planning systems causes a reduction in the complexities of the treatment techniques. The most effective method to assess the dosimetric accuracy and the validity of the ...

background: ebt and ebt3 radiochromic films have been used in radiotherapy dosimetry for years. objective: the aim of the current study is to compare ebt and ebt3 radiochromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. methods: calibrations of ebt and ebt3 films were performed with identical setups using a 6 mv photon beam of a siemens primus linac. skin dose was...

Background: Radiotherapy is an important technique of cancer treatment using ionizing radiation. The determination of total dose in reference conditions is an important contribution to uncertainty that could achieve 2%. The source of this uncertainty comes from cavity theory that relates the in-air cavity dose and the dose to water. These correction factors are determined from Monte Carlo calcu...

BACKGROUND AND PURPOSE To assess the effect of differences in the calculation of the dose outside segment edges on the overall dose distribution and the optimisation process of intensity modulated radiation therapy (IMRT) treatment plans. PATIENTS AND METHODS Accuracy of dose calculations of two treatment planning systems (TPS1 and TPS2) was assessed, to ensure that they are both suitable for...

Introduction: Intensity modulated radiation therapy (IMRT) is one of the cancer treatment methods. It is important to selectively aim at the target in this way, which can be performed using a multileaf collimator (MLC). Materials and Methods: In order to specifically irradiate the target volume in radiotherapy to reduce the patient absorbed dose, the use of multileaf collimator has been investi...

Monte Carlo codes are utilized for accurate dose calculations in proton radiation therapy research. While they are superior in accuracy to commonly used analytical dose calculations, they require significantly longer computation times. The aim of this work is to characterize a Monte Carlo track-repeating algorithm to increase computation speed without compromising dosimetric accuracy. The track...

background: inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. objective: in the present study, the performance of five algorithms via monte carlo, pencil beam, convolution, fast superposition and superposition were evaluated in lung cancer intensity modulated radiotherapy planni...