نتایج جستجو برای: monte carlo polymer gel radiotherapy

تعداد نتایج: 326301  

Journal: :iranian journal of medical physics 0
hamid reza sadoughi m.sc. student of medical physics, medical physics dept., tehran university of medical sciences, tehran, iran mahmood allahverdi associate professor, medical physics dept., tehran university of medical sciences, and radiotherapy physics department of cancer institute, tehran, iran hasan nedaei assistant professor, radiotherapy physics dept., cancer institute, tehran, iran ramin jaberi radiotherapy physicist, radiotherapy physics dept., cancer institute, tehran, iran mahbod esfahani radiotherapy physicist, radiotherapy physics dept., cancer institute, tehran, iran alireza shirazi associated professor, medical physics dept., tehran university of medical sciences, tehran, iran

introduction: multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. in this work, we investigated mr-based magic gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. materials and methods: a heterogeneous slab phantom including bones was made....

Background and purpose: Radiation therapy make an important contribution in the control and treatment of cancers. Lungs are the main organs at risk in esophageal cancer radiotherapy. Difference between the dose distribution due to the treatment planning system (TPS) and the patient's body dose is dependent on the calculation of the treatment planning system algorithm, which is more pronounced i...

Background: Normoxic type MAGICA gel dosimeters are established for dose quantification in three dimensions for radiotherapy. Objective(s): The ability of MAGICA polymer gel was assessed by experimental measurements method for studying the effect of gold nanoparticles (GNPs) in dose enhancement under the external 18MV radiotherapy practices. <...

2006
G. Gambarini D. Brusa M. Carrara G. Castellano M. Mariani M. Valente E. Vanossi

Abstract. Gel dosimeters are integrating dosimeters, that enable dose verification in three dimensions. Optical analysis of gel dosimeters has demonstrated to be an available technique for imaging the absorbed in-phantom dose exposed to radiotherapy beams. The goal is to demonstrate the ability of gel dosimeters to achieve accurately and spatial resolution in dose mapping, also when high dose r...

Ali Shabestani Monfared, Mehdi Khobi Nader Riahi Alam Shiva Shoobkolaei

Introduction: Bismuth-based nanoparticles having high atomic number and electron density, besides of being utilized as CT contrast agent, stand as a strongly proposed method for dose enhancement in radiotherapy. Embedded nanoparticle in polymer gel dosimeter poses the first step to assess the dose enhancement capability in nanoparticles. To this end, MAGICA gel dosimeter, whic...

Gh. Ataei M. Khadem-Abolfazli M. Mahdavi, S. R. M. Mahdavi

Background: Radiation-sensitive polymer gels are among the most promising three-dimensional dose verification tools and tissue-like phantom developed to date.Objective: The aim of this study is an investigating of percentage depth dose enhancement within the gel medium with used of conformal distribution gold nanoparticle as contrast agents by high atomic number material.Methods: In this work t...

2003
J. Bergenholtz W. C. K. Poon M. Fuchs

Mode coupling theory (MCT) is used to model gel formation in mixtures of colloidal particles and nonadsorbing polymer. The polymer induces an effective, short-range attraction among the colloids, which is modeled by a depletion attraction of the Asakura-Oosawa form. This enables the MCT to be solved analytically for dilute systems, leading to a prediction, free of adjustable parameters, of the ...

2007
Jouni Uusi–Simola Sami Heikkinen Petri Kotiluoto Tom Serén Tiina Seppälä Iiro Auterinen Sauli Savolainen

Radiation sensitive polymer gels are among the most promising three-dimensional dose verification tools developed to date. Polymer gel dosimeter known by the acronym MAGIC has been tested for evaluation of its use in boron neutron capture (BNCT) dosimetry. We irradiated a large (diameter 10 cm, length 20 cm) cylindrical gel phantom in the epithermal neutron beam of the Finnish BNCT facility at ...

Journal: :Annali dell'Istituto superiore di sanita 2010
Barbara Caccia Claudio Andenna Giuseppe Antonio Pablo Cirrone

Dose distribution evaluation in oncological radiotherapy treatments is an outstanding problem that requires sophisticated computing technologies to optimize the clinical results (i.e. increase the dose to the tumour and reduce the dose to the healthy tissues). Nowdays, dose calculation algorithms based on the Monte Carlo method are generally regarded as the most accurate tools for radiotherapy....

Journal: :journal of biomedical physics and engineering 0
s a rahimi tarbiat modares university b hashemi tarbiat modares university s r mahdavi iran university of medical sciences

background: estimating dosimetric parameters for small fields under non-reference conditions leads to significant errors if done based on conventional protocols used for large fields in reference conditions. hence, further correction factors have been introduced to take into account the influence of spectral quality changes when various detectors are used in non-reference conditions at differen...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید