background: 3dcrt (three-dimensional conformal radiotherapy) and imrt (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. however, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. the purpose of this study is to evaluate the imp...

introduction one of the important applications of nuclear physics in medicine is the use of radioactive elements as radiopharmaceuticals. metastatic bone disease is the most common form of malignant bone tumors. samarium-153-ethylene diamine tetramethylene phosphonate (153sm-edtmp) as a radiopharmaceutical is used for pain palliation. this radiopharmaceutical usually emits beta particles, which...

background: the aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or pmma), a150 plastic and te- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. materials and methods: thermal neutron fluence, photon dose and epithermal neut...

introduction: among different kinds of oral cavity cancers, the frequency of tongue cancer occurrence is more significant. brachytherapy is the most common method to cure tongue cancers. long sources are used in different techniques of tongue brachytherapy. the objective of this study is to asses the dose distribution around long sources, comparing different radioisotopes as brachytherapy sourc...

introduction: clinical application of encapsulated radioactive brachytherapy sources has a major role in cancer treatment. in the present research, the effects of different tissue densities on the dose distribution of a 103pd brachytherapy source in a spherical phantom of 50 cm radius have been studied. material and methods: as is well known, absorbed dose in tissue depends to its density, but ...

background: in radiation treatment of moving targets located in thorax region of patient body, the delivered dose does not match with the planned treatment, resulting in some over and under dosage in the tumor volume, as a function of motion magnitude and frequency. several efforts have been done to investigate the target motion effects on dose distribution in the target and surrounding normal ...

background: palladium-103 (103pd) is a brachytherapy source for cancer treatment. the monte carlo codes are usually applied for dose distribution and effect of shieldings. monte carlo calculation of dose distribution in water phantom due to a med3633 103pd source is presented in this work. materials and methods: the dose distribution around the 103pd model med3633 located in the center of 30×30...

background: monte carlo determination of tg-43 brachytherapy dosimetry parameters and dose distribution calculation for 131cs source model cs-1 are presented in this study. materials and methods: the dose distribution was calculated around the 131cs model cs-1 located in the center of 30 cm ×30 cm ×30 cm water, and soft tissue phantoms cube using mcnp code by monte carlo method. the percentage ...

background: polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. mri polymer gel dosimeters are tissue equivalent and can act as a phantom material. in this study the obtained isodose maps with pagat polymer gel dosimeter were compared to those calculated with egsnrs for singleshot irradiations of 8 and 18 mm collimators of gamma ...

background: to enhance the dose to tumor, the use of high atomic number elements has been proposed. objective: the aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic x-ray beams by considering homogeneous and inhomogeneous distributions of gold nanoparticles (gnps) in the tumor. meth...