نتایج جستجو برای: egsnrc

تعداد نتایج: 222  

A Chairmadurai C Bhatt D Shrotiya L Chaudhari N Painuly, N Singh, T Verma

Aims: The aims of the present work are (1) to evaluate dose calculation accuracy of two commonly used algorithms for 15 MV small photon fields in a medium encompassing heterogeneity and (2) to compare them with measured results obtained from gafchromic film EBT2.Materials and Methods: Authors employed kailwood (Pinus Wallichiana) to mimic lung. Briefly, seven Kailwood plates, each measuring 25x...

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...

Journal: :iranian journal of radiation research 0
z. salehi department of adp, school of pre-u, kdu university, selangor, malaysia w.a. kamil department of radiology, school of medical sciences, university sains malaysia, 16150 kubang kerian, kelantan, malaysia b.m. biswal department of radiotherapy & oncology, kpj ipoh specialist hospital, 30350 ipoh, perak, malaysia a.l. yusoff department of nuclear medicine, radiotherapy and oncology, school of medical sciences, university sains malaysia, 16150 kubang kerian, kelantan, malaysia

background: the purpose of this study was to find the accurate absorbed dose in the femur bone marrow during the x-ray radiography for constant mas and aec techniques. materials and methods: the dosxyznrc was used to simulate radiation doses in two human femurs during diagnostic radiography. egsnrc phantoms produced from actual ct images of human femurs were modified by adding seven micrometre ...

Journal: :iranian journal of medical physics 0
micaeil mollazadeh m.sc. student in medical physics, medical physics and engineering dept., tehran university of medical sciences, tehran, iran. mahmood allahverdi associate professor, medical physics and engineering dept., tehran university of medical sciences, tehran, iran. tayyeb allahverdi pourfallah assistant professor, biochemistry and biophysics dept., mazandaran university of medical sciences, sari, iran. nader riahi alam associate professor, medical physics and engineering dept., tehran university of medical sciences, tehran, iran. mohammadreza ay associate professor, medical physics and engineering dept., tehran university of medical sciences, tehran, iran.

introduction: gafchromic ebt films are one of the self-developing and modern films commercially available for dosimetric verification of treatment planning systems (tpss). their high spatial resolution, low energy dependence and near-tissue equivalence make them suitable for verification of dose distributions in radiation therapy. this study was designed to evaluate the dosimetric parameters of...

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...

2012
Mahdi Sadeghi Pooneh Saidi Claudio Tenreiro

The term of brachytherapy, also known as “internal radiotherapy, sealed source radiotherapy, curietherapy or endocurietherapy” is from Greek work brachy means short distance and therapy (treatment) and also known as internal radiotherapy or sealed source radiotherapy. Brachytherapy is a special form of radiotherapy where a radioactive source is carefully placed on or inside the area to be treat...

Journal: :Physics in medicine and biology 2013
D Czarnecki K Zink

The application of small photon fields in modern radiotherapy requires the determination of total scatter factors Scp or field factors Ω(f(clin), f(msr))(Q(clin), Q(msr)) with high precision. Both quantities require the knowledge of the field-size-dependent and detector-dependent correction factor k(f(clin), f(msr))(Q(clin), Q(msr)). The aim of this study is the determination of the correction ...

2014
Yoshitomo Ishihara Akira Sawada Mitsuhiro Nakamura Yuki Miyabe Hiroaki Tanabe Shuji Kaneko Kenji Takayama Takashi Mizowaki Masaki Kokubo Masahiro Hiraoka

Vero4DRT is an innovative image-guided radiotherapy system employing a C-band X-ray head with gimbal mechanics. The purposes of this study were to propose specific MC models of the linac head and multileaf collimator (MLC) for the Vero4DRT and to verify their accuracy. For a 6 MV photon beam delivered by the Vero4DRT, a simulation code was implemented using EGSnrc. The linac head model and the ...

Journal: :Medical physics 2014
Regina K Fulkerson John A Micka Larry A DeWerd

PURPOSE Historically, treatment of malignant surface lesions has been achieved with linear accelerator based electron beams or superficial x-ray beams. Recent developments in the field of brachytherapy now allow for the treatment of surface lesions with specialized conical applicators placed directly on the lesion. Applicators are available for use with high dose rate (HDR)(192)Ir sources, as w...

Journal: :Physics in medicine and biology 2010
R Kramer V F Cassola H J Khoury J W Vieira V J de Melo Lima K Robson Brown

Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been developed in the first part of this study using 3D animation software and anatomical atlases to replace the image-based FAX06 and the MAX06 voxel phantoms. 3D modelling methods allow for phantom development independent from medical images of patients, volunteers or cadavers. The second pa...

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