In June 2007, the United States Department of Energy incorporated revised values of neutron weighting factors into its occupational radiation protection regulation Title 10, Code of Federal Regulations Part 835, as part of updating its radiation dosimetry system. This has led to a reassessment of neutron radiation fields at high energy accelerators such as those at the Fermi National Accelerato...

The use of radiochromic film (RCF) dosimetry is widely consolidated for applications in photon, electron and proton beams. It offers several advantages, in particular, two-dimensional measurements of dose distributions with high spatial resolution, no post irradiation processing required and no daylight sensitivity. In addition, it shows small LET and energy dependence. GAFCHROMIC® EBT3 films, ...

Introduction: In recent decades, several Monte Carlo codes have been introduced for research and medical applications. These methods provide both accurate and detailed calculation of particle transport from linear accelerators. The main drawback of Monte Carlo techniques is the extremely long computing time that is required in order to obtain a dose distribution with good statistical accuracy. ...

OBJECTIVE To compare treatment plans obtained with the CyberKnife (CK) (Accuray, Inc., Sunnyvale, CA) with those of other commonly used radiosurgical modalities, such as the gamma knife (GK), linear accelerator multiple arcs, conformally shaped static fields, and intensity-modulated radiotherapy (IMRT). METHODS An ellipsoidal simulated target was chosen centrally located in a three-dimensiona...

Introduction: Small field dosimetry is challenging for radiotherapy dosimetry. measurement of the output factor in the air and water (Sc, Scp) is one of the input parameters for commissioning of treatment planning systems and beam modeling. The aims of this study are to measured Sc,Scp for small fields with EBT2 and Ion chamber and design a appropriate mini-phantom for small fi...

The purpose of this study was to experimentally quantify the change in response of an amorphous silicon (a-Si) electronic portal imaging device (EPID) to dynamic multileaf collimator (dMLC) beams with varying MLC-transmitted dose components and incorporate the response into a commercial treatment planning system (TPS) EPID prediction model. A combination of uniform intensity dMLC beams and stat...

PURPOSE To quantify the ability of electronic portal imaging device (EPID) dosimetry used during treatment (in vivo) in detecting variations that can occur in the course of patient treatment. METHODS Images of transmitted radiation from in vivo EPID measurements were converted to a 2D planar dose at isocenter and compared to the treatment planning dose using a prototype software system. Using...

The use of a diabetic blood glucose meter for radiochromic film dosimetry in blood irradiation using x-ray beams on a medical linear accelerator has been investigated. The glucose meter provides optical density analysis in the visible and infrared region using a reflectance measurement technique. By comparing the 'blood sugar' level output with standard calibration gafchromic films a calibratio...

Background: Attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. So, its exact measurement or calculation is very important. The aim of this study was to evaluate the μ in different points in the water phantom anal...