نتایج جستجو برای: megavoltage photons

تعداد نتایج: 47760  

2015
Ekkasit Tharavichitkul Suwapim Janla-or Somsak Wanwilairat Somvilai Chakrabandhu Pitchayaponne Klunklin Wimrak Onchan Bongkot Supawongwattana Razvan M. Galalae Imjai Chitapanarux

We present a case of cervical cancer treated by concurrent chemoradiation. In radiation therapy part, the combination of the whole pelvic helical tomotherapy plus image-guided brachytherapy with megavoltage computed tomography of helical tomotherapy was performed. We propose this therapeutic approach could be considered in a curative setting in some problematic situation as our institution.

2015
Vikneswary Batumalai Alexandra Quinn Michael Jameson Geoff Delaney Lois Holloway

INTRODUCTION Correct target positioning is crucial for accurate dose delivery in breast radiotherapy resulting in utilisation of daily imaging. However, the radiation dose from daily imaging is associated with increased probability of secondary induced cancer. The aim of this study was to quantify doses associated with three imaging modalities and investigate the correlation of dose and varying...

Journal: :Medical physics 2002
H Keller M Glass R Hinderer K Ruchala R Jeraj G Olivera T Rock Mackie

The imaging characteristics of an arc-shaped xenon gas ionization chamber for the purpose of megavoltage CT imaging were investigated. The detector consists of several hundred 320 microm thick gas cavities separated by thin tungsten plates of the same thickness. Dose response, efficiency and resolution parameters were calculated using Monte Carlo simulations. The calculations were compared to m...

Journal: :iranian journal of medical physics 0
mohammad amin mosleh-shirazi physics unit, department of radiotherapy and oncology, namazi hospital, shiraz university of medical sciences, shiraz, iran 2- ionizing and non-ionizing radiation protection research center, school of paramedical sciences, shiraz university of medical sciences, shiraz, iran saeed rahimi department of medical physics and engineering, school of medicine, shiraz university of medical sciences, shiraz, iran student research committee, shiraz university of medical sciences, shiraz, iran sareh karbasi physics unit, department of radiotherapy and oncology, namazi hospital, shiraz university of medical sciences, shiraz, iran

introduction in this study, we aimed to assess the medium-term energy stability of a 6mv elekta compacttm linear accelerator. to the best of our knowledge, this is the first published article to evaluate this linear accelerator in terms of energy stability. as well as investigating the stability of the linear accelerator energy over a period of several weeks, the results will be useful for esti...

Journal: :international journal of optics and photonics 0
siamak khademi department of physics, university of zanjan samira alipour department of physics, university of zanjan

the semi-classical model of atom-field interaction has been fully studied for some multilevel atoms, e.g. vee, l, cascade x , y, and inverted y and so on. this issue is developed into the full-quantum electrodynamics formalism, where the probe and coupling electromagnetic fields are quantized. in this article, we investigate the full-quantum model of absorption and dispersion spectrum of trappe...

Journal: :Reports of Practical Oncology & Radiotherapy 2013

Alireza Emami-Ardekani Alireza Mardanshahi, Faraz Kalantari, Mahmoud Bagheri Mohammad Sobhan Ardekani Nasim Namiranian Reza Nafisi-Moghadam Seid Kazem Razavi-Ratki, Seyed Hossein Razavi,

Introduction:In an ideal parallel-hole collimator, thickness of septal material should be sufficient to stop more than 95% of incident photons. However, some photons pass the septa without interaction or experience scattering before they reach the detector. In this study, we determined different contribution of collimator responses consist of geometrical response, septal penetr...

Journal: :iranian journal of radiation research 0
s.m.j. mortazavi school of paramedical sciences and the center for radiological research, shiraz university of medical sciences, shiraz, iran m.a. mosleh-shirazi radiotherapy physics unit, radiotherapy department and center for research in medical physics and biomedical engineering, shiraz university of medical sciences, shiraz, iran m. baradaran-ghahfarokhi depatment of nuclear engineering, school of engineering, shiraz university, shiraz, iran z. siavashpour depatment of nuclear engineering, school of engineering, shiraz university, shiraz, iran a. farshadi depatment of nuclear engineering, school of engineering, shiraz university, shiraz, iran m. ghafoori secondary standard dosimetry laboratory, agricultural, medical and industrial research school, nuclear science and technology research institute, aeoi, tehran, iran

background: biological shielding of nuclear reactors has always been a great concern and decreasing the complexity and expense of these installations is of great interest. in this study, we used datolite and galena (daga) minerals for production of a high performance heavy concrete. materials and methods: datolite and galena minerals which can be found in many parts of iran were used in the con...

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