Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-10-5
pubmed:abstractText
Testing computer-controlled linear accelerators for patient safety and proper patient dose delivery requires that certain beam characteristics be monitored over an extended period of time. Computer-controlled conformal radiation therapy using asymmetric collimator jaw settings necessitates stable symmetric treatment beams. Long term beam symmetry measurements have been performed on a Philips SL20 dual energy computer-controlled linear accelerator. Symmetry in both the radial and transverse axis of each x-ray beam was monitored for eight gantry positions. These measurements were undertaken to determine the effectiveness of the SL20 beam steering system during dose delivery of 50 monitor units (MU) per field. Evaluation of the data shows that careful beam steering setup procedures result in x-ray beams in which fluctuations in symmetry as a function of gantry angle are within +/- 1.5%. Day to day instabilities produce a total overall variation in beam symmetry on the order of +/- 2.0%. Results suggest the measurement of symmetry as a function of gantry position become a routine quality assurance procedure for this accelerator.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0094-2405
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
614-7
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:articleTitle
Long term variation in beam symmetry as a function of gantry angle for a computer-controlled linear accelerator.
pubmed:affiliation
Department of Radiation Therapy, University of Texas Medical Branch, Galveston 77550.
pubmed:publicationType
Journal Article