نتایج جستجو برای: dose calculation

تعداد نتایج: 408802  

Large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. Therefore, radiation unwanted dose is created in kidney. As a result, exact calculation of prescribed radiopharmaceuticals amount is important. Monte Carlo method is used for simulation of radiation transport in body due to random nature of radiation. In this research, for the first time...

Journal: :iranian journal of radiation research 0
a. mesbahi medical physics department, medical school, tabriz university of medical sciences, tabriz, iran a. haghzadeh engineering faculty, medical radiation engineering department, azad university, science and research branch, tehran, iran a.r. naseri radiation oncology department, imam hospital, tabriz, iran a.r. naseri engineering faculty, medical radiation engineering department, azad university, science and research branch, tehran, iran

background: in the current study the effect of shielded colpostat on rectum received dose was calculated in cervical brachytherapy using monte carlo (mc) method. materials and methods: two 60co sources of gzp6 brachytherapy unit used for intracavitary treatments were simulated using mcnpx monte carlo code. also the two types of colpostats including shielded and unshielded were simulated inside ...

Journal: :journal of medical signals and sensors 0
keivan jabbari hossein saberi anvar mohammad bagher tavakoli alireza amouheidari

background: the monte carlo method is the most accurate method for simulation of radiation therapy equipment. the linear accelerators are currently the most widely used machines in radiation therapy centers. methods: in this work, a monte carlo modelling of the siemens oncor linear accelerator in 6 mv and 18 mv beams was performed. the results of simulation were validated by measurements in wat...

2013
Emma Hedin Anna Bäck

Due to limitations and uncertainties in dose calculation algorithms, different algorithms can predict different dose distributions and dose-volume histograms for the same treatment. This can be a problem when estimating the normal tissue complication probability (NTCP) for patient-specific dose distributions. Published NTCP model parameters are often derived for a different dose calculation alg...

2008
Kazeem A. Oshikoya Idowu O. Senbanjo Ayo Soipe

UNLABELLED Dose calculation errors constitute a significant part of prescribing errors which might have resulted from informal teaching of the topic in medical schools. OBJECTIVES To determine adequacy of knowledge and skills of drug dose calculations in children acquired by medical students during their clinical attachment in paediatrics. METHODS Fifty two 5th year medical students of the ...

2017
Motohiro Kawashima Hidemasa Kawamura Masahiro Onishi Yosuke Takakusagi Noriyuki Okonogi Atsushi Okazaki Tetsuo Sekihara Yoshitaka Ando Takashi Nakano

Discretization errors due to the digitization of computed tomography images and the calculation grid are a significant issue in radiation therapy. Such errors have been quantitatively reported for a fixed multifield intensity-modulated radiation therapy using traditional linear accelerators. The aim of this study is to quantify the influence of the calculation grid size on the dose distribution...

Introduction:  All of  the  people worldwide  are exposed  to  low levels  of  radiation. Cancer induction  and  genetic disorders are among the hazards of low level exposure. In some cases, radiation close to hot springs is  higher than normal areas due to a high concentration and the decay products of Ra-226. Given the use of hot  springs by the general public  because  of their therapeutic p...

Journal: :Nihon Hoshasen Gijutsu Gakkai zasshi 2013
Yuki Tomiyama Fujio Araki Nagisa Kanetake Yoshinobu Shimohigashi Hirofumi Tominaga Jyunichi Sakata Takeshi Oono Tomohiro Kouno Kazunari Hioki

Dose calculation algorithms in radiation treatment planning systems (RTPSs) play a crucial role in stereotactic body radiation therapy (SBRT) in the lung with heterogeneous media. This study investigated the performance and accuracy of dose calculation for three algorithms: analytical anisotropic algorithm (AAA), pencil beam convolution (PBC) and Acuros XB (AXB) in Eclipse (Varian Medical Syste...

2014
Kenichi Tanaka Kunihiko Tateoka Osamu Asanuma Ken-ichi Kamo Kaori Sato Hiromitsu Takeda Masaru Takagi Masato Hareyama Jun Takada

The post-implantation dosimetry for brachytherapy using Monte Carlo calculation by EGS5 code combined with the source strength regression was investigated with respect to its validity. In this method, the source strength for the EGS5 calculation was adjusted with the regression, so that the calculation would reproduce the dose monitored with the glass rod dosimeters (GRDs) on a water phantom. T...

ژورنال: سنجش و ایمنی پرتو 2014

In this paper, graphite calorimeter device which is using to calibrate the electron beam of therapy accelerators in the range of the low dose was simulated using the EGS4 calculation code. Then, the electron beam dose distributions were calculated in it and the effects of parameters such as thickness of the calorimeter core, the distance to the source, thickness of air gap around the core, thic...

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