An experimental investigation of the tongue and groove effect for the Philips multileaf collimator.

2.50
Hdl Handle:
http://hdl.handle.net/10541/91667
Title:
An experimental investigation of the tongue and groove effect for the Philips multileaf collimator.
Authors:
Sykes, Jonathan R; Williams, Peter C
Abstract:
The tongue and groove effect is an underdosing effect which can occur in certain applications of multileaf collimators. It results from the need to overlap adjacent leaves of a multileaf collimator in order to limit leakage between leaves. The applications in which the effect can occur are the abutment of fields where the beam edges are defined by the leaf edge and the production of intensity-modulated fields by dynamic collimation. The effect has been measured for the 'worst case' when just two MLC fields are matched along leaf edges which have overlapping steps. Measurements of the dose have been made at d(max) and also at a more clinically relevant depth of 87 mm in Perspex for beam energies of 6 MV, 8 MV and 20 MV on two Philips SL series accelerators. Dose distributions were recorded on radiographic film which was subsequently digitized for analysis. The dose reduction of the tongue and groove effect was found to be 15-28% and spread over a width of 3.8 to 4.2 mm. This is somewhat shallower and wider than would be expected from a simple, idealized model of the effect which would predict a dose reduction of 80% over a width of 1 mm.
Affiliation:
North Western Medical Physics Department, Christie Hospital NHS Trust, Manchester, UK. prsjrs@dalpha2.cr.man.uk
Citation:
An experimental investigation of the tongue and groove effect for the Philips multileaf collimator. 1998, 43 (10):3157-65 Phys Med Biol
Journal:
Physics in Medicine and Biology
Issue Date:
Oct-1998
URI:
http://hdl.handle.net/10541/91667
DOI:
10.1088/0031-9155/43/10/034
PubMed ID:
9814543
Type:
Article
Language:
en
ISSN:
0031-9155
Appears in Collections:
All Christie Publications

Full metadata record

DC FieldValue Language
dc.contributor.authorSykes, Jonathan Ren
dc.contributor.authorWilliams, Peter Cen
dc.date.accessioned2010-02-09T16:53:24Z-
dc.date.available2010-02-09T16:53:24Z-
dc.date.issued1998-10-
dc.identifier.citationAn experimental investigation of the tongue and groove effect for the Philips multileaf collimator. 1998, 43 (10):3157-65 Phys Med Biolen
dc.identifier.issn0031-9155-
dc.identifier.pmid9814543-
dc.identifier.doi10.1088/0031-9155/43/10/034-
dc.identifier.urihttp://hdl.handle.net/10541/91667-
dc.description.abstractThe tongue and groove effect is an underdosing effect which can occur in certain applications of multileaf collimators. It results from the need to overlap adjacent leaves of a multileaf collimator in order to limit leakage between leaves. The applications in which the effect can occur are the abutment of fields where the beam edges are defined by the leaf edge and the production of intensity-modulated fields by dynamic collimation. The effect has been measured for the 'worst case' when just two MLC fields are matched along leaf edges which have overlapping steps. Measurements of the dose have been made at d(max) and also at a more clinically relevant depth of 87 mm in Perspex for beam energies of 6 MV, 8 MV and 20 MV on two Philips SL series accelerators. Dose distributions were recorded on radiographic film which was subsequently digitized for analysis. The dose reduction of the tongue and groove effect was found to be 15-28% and spread over a width of 3.8 to 4.2 mm. This is somewhat shallower and wider than would be expected from a simple, idealized model of the effect which would predict a dose reduction of 80% over a width of 1 mm.en
dc.language.isoenen
dc.subject.meshParticle Accelerators-
dc.subject.meshRadiation, Ionizing-
dc.subject.meshRadiometry-
dc.subject.meshRadiotherapy-
dc.subject.meshX-Ray Film-
dc.subject.meshX-Rays-
dc.titleAn experimental investigation of the tongue and groove effect for the Philips multileaf collimator.en
dc.typeArticleen
dc.contributor.departmentNorth Western Medical Physics Department, Christie Hospital NHS Trust, Manchester, UK. prsjrs@dalpha2.cr.man.uken
dc.identifier.journalPhysics in Medicine and Biologyen

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