Document Detail

Study and evaluation of the Siemens virtual wedge factor: dosimetric monitor system and variable field effects.
MedLine Citation:
PMID:  18296764     Owner:  NLM     Status:  MEDLINE    
In the year 1997 Siemens introduced the virtual wedge in its accelerators. The idea was that a dose profile similar to that of a physical wedge can be obtained by moving one of the accelerator jaws at a constant speed while the dose rate is changing. This work explores the observed behaviour of virtual wedge factors. A model is suggested which takes into account that at any point in time, when the jaw moves, the dose at a point of interest in the phantom is not only due to the direct beam. It also depends on the scattered radiation in the phantom, the head scatter and the behaviour of the monitoring system of the accelerator. Measurements are performed in a Siemens Primus accelerator and compared to the model predictions. It is shown that the model agrees reasonably well with measurements spanning a wide range of conditions. A strong dependence of virtual wedge factors on the dosimetric board has been confirmed and an explanation has been given on how the balance between different contributions is responsible for virtual wedge factors values.
J R Sendón Del Río; C Otero Martínez; M Sánchez García; R Lobato Busto; V Luna Vega; J Mosquera Sueiro; M Pombar Cameán
Related Documents :
16898444 - Dose uncertainty due to aperture effects in dynamic fields.
20407594 - An investigation into the robustness of optical-ct dosimetry of a radiochromic dosimete...
20305334 - Out-of-field photon dose following removal of the flattening filter from a medical acce...
16644954 - Monte carlo simulation of the photon beam characteristics from medical linear accelerat...
25321774 - Near-field probing of mie resonances in single tio2 microspheres at terahertz frequencies.
23388994 - Optical guided mode resonance filter on a flexible substrate.
Publication Detail:
Type:  Journal Article     Date:  2008-02-13
Journal Detail:
Title:  Physics in medicine and biology     Volume:  53     ISSN:  0031-9155     ISO Abbreviation:  Phys Med Biol     Publication Date:  2008 Mar 
Date Detail:
Created Date:  2008-02-25     Completed Date:  2008-06-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0401220     Medline TA:  Phys Med Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  1313-23     Citation Subset:  IM    
Servizo de Radiofísica e Protección Radiolóxica, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Santiago de Compostela, Spain.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Radiometry / methods*
Radiotherapy Dosage
Radiotherapy, Conformal
Reproducibility of Results

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Effect of CT scanning parameters on volumetric measurements of pulmonary nodules by 3D active contou...
Next Document:  Investigation of the signal behavior at diagnostic energies of prototype, direct detection, active m...