monte carlo method is a very accurate method to optimize medical diagnostic radiology spectra and simulation of radiation transportation. using mcnp code, radiology and mammography attenuated x-rayspectraweresimulated.the ipem report number 78 was used as a reference to compare with the geant4 and mcnp simulations because of its popularity and wide availability. the results of geant4 in 40kev s...

Neutron dose-equivalent buildup factors were calculated for point isotropic neutron sources irradiating infinite slablike shields of lead, iron and water using the MCNP code. The factors are presented for some source neutron energies in the range from 0.025 eV to 14 MeV, and for shield thicknesses from 0.5 to 10 mfp. Since the MCNP code considers all kinds of neutron interactions with matter, a...

Introduction: Stereotactic body radiotherapy delivers hypofractionated irradiation with high dose per fraction through complex treatment techniques. The increased complexity leads to longer dose delivery times for each fraction. The purpose of this study is to investigate the impact of prolonged fraction delivery time with high-dose hypofractionation on the killing of cultured ACHN cells.Method...

AIM The purpose of this study is to calculate radiation dose around a brachytherapy source in a water phantom for different seed locations or rotation the sources by the matrix summation method. BACKGROUND Monte Carlo based codes like MCNP are widely used for performing radiation transport calculations and dose evaluation in brachytherapy. But for complicated situations, like using more than ...

Objective(s): The purpose of this research is to study the effect of beta spectrum on absorbed fraction ( ) and to find suitable analytical functions for beta spectrum absorbed fractions in spherical and ellipsoidal volumes with a uniform distribution for several radionuclides that are commonly used in nuclear medicine.Methods: In order to obtain the beta particle absorbed fraction, Monte Carlo...

introduction: in brachytherapy, radioactive sources are placed close to the tumor, therefore, small changes in their positions can cause large changes in the dose distribution. this emphasizes the need for computerized treatment planning. the usual method for treatment planning of cervix brachytherapy uses conventional radiographs in the manchester system. nowadays, because of their advantages ...

background: most preclinical studies are carried out on mice. for internal dose  assessment of a mouse, specific absorbed fraction (saf) values play an important role.  in most studies, saf values are estimated using older standard human organ compositions  and values for limited source target pairs. objective: saf values for monoenergetic photons of energies 15, 50, 100, 500,  1000 and 4000 ke...

The IAEA Code of Practice for Absorbed Dose Determination in Photon and Electron Beams TRS 277 gives recommendations for the absorbed dose determination in high energy photon and electron beams based on the use of ionization chambers calibrated in terms of air kerma. It was the task of the present work to test the validity of the Code for *°Co gamma radiation for ton different types of ionizati...

BACKGROUND PET/CT has recently been shown to be a viable alternative to traditional post-infusion imaging methods providing good quality images of 90Y-laden microspheres after selective internal radiation therapy (SIRT). In the present paper, first we assessed the quantitative accuracy of 90Y-PET using an anthropomorphic phantom provided with lungs, liver, spine, and a cylindrical homemade lesi...

In the event of a radiological accident caused by an external source, estimating the dose distribution in the victim's body is a relevant indicator in assessing biological damage from this exposure. This dose distribution can be assessed by physical dosimetric reconstruction methods. Physical dosimetric reconstruction can be achieved using experimental or numerical techniques. This article pres...