ABSTRACTBackground: Monte Carlo simulation has been used by many researchers to calculate organ and effective dose of patients arising from conventional X-ray examinations. In this study the radiation transport code, MCNP-4C, has been used to perform Monte Carlo simulations to estimate radiation dose delivered to different organs in conventional X-ray examinations.Material and Methods: In this...

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...

Background: For preclinical evaluations of radiopharmaceuticals, most studies are carried out on mice. Values of electron specific absorbed fractions (SAF) have had vital role in the assessment of absorbed dose. In past studies, electron specific absorbed fractions were given for limited source target pairs using older reports of human organ compositions.Objective: Electron specific absorbed fr...

Background: Breast cancer is the most frequently diagnosed cancer and the leading global cause of cancer death among women worldwide. Radiotherapy plays a significant role in treatment of breast cancer and reduces locoregional recurrence and eventually improves survival. The treatment fields applied for breast cancer treatment include: tangential, axillary, supraclavicular and internal mammary ...

This study evaluated a method for prostate intensity-modulated radiation therapy (IMRT) based on edge-enhanced (EE) intensity in the presence of intrafraction organ deformation using the data of 37 patients treated with step-and-shoot IMRT. On the assumption that the patient setup error was already accounted for by image guidance, only organ deformation over the treatment course was considered....

Intensity-modulated radiation therapy can be conveniently delivered with a multileaf collimator. With this method, the entire field is not delivered at once, but rather it is composed of many subfields defined by the leaf positions as a function of beam on time. At any given instant, only these subfields are delivered. During treatment, if the organ moves, part of the volume may move in or out ...

Introduction: In this study, organ radiation doses were calculated for the renal agent 99mTc-DTPA in children. Bio-kinetic energy of 99mTc-DTPA was evaluated by scintigraphy and estimates for absorbed radiation dose were provided using standard medical internal radiation dosimetry (MIRD) techniques.Material and Methods: In this applied research, fourteen children patients (6 males and 8 females...

background: punica granatum linn. (pg) is native to the mediterranean region. its flower exhibited antioxidant activity. the present study attempt to investigate the effect of these extract on uterine contraction and its possible mechanism(s). methods: thirty five female wistar rats (200-300 g) at estrous phases of cycle was examined in this study; pieces of virgin adult rat uterus (1.5 cm) wer...

PURPOSE To compare the dose and image quality of three methods for reducing the radiation dose to the eye at head computed tomography (CT): bismuth shielding, organ-based tube current modulation (TCM), and global reduction of the tube current. MATERIALS AND METHODS An anthropomorphic head phantom was scanned under six conditions: (a) without any dose reduction techniques (reference scanning);...

For determining the absorbed dose of ionizing radiation is tissues, it is essential to have materials which behave like tissues. These kinds of materials are usually called phantom. Up to now many different compounds like water, rubber, Perspex etc have been used. Unfortunately, the practical use of each of them has had its own problems. Our suggested gelatin phantom is very similar to soft...