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The omni wedge: A method to produce wedged fields at arbitrary orientations
Author(s) -
Milliken Barrett D.,
Hamilton Russell J.,
Rubin Steven J.
Publication year - 1996
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.597663
Subject(s) - collimator , multileaf collimator , wedge (geometry) , orientation (vector space) , optics , weighting , rotation (mathematics) , geometry , physics , mathematics , linear particle accelerator , beam (structure) , acoustics
A method to produce wedged fields at any orientation relative to the collimator is described. The wedged field is generated by combining two appropriately weighted orthogonal wedged field segments at fixed collimator and gantry positions. The method requires only that wedged fields can be produced in orthogonal directions without rotating the collimator, such as is commonly provided on most radiation therapy accelerators by sets of standard and rotated wedges. Expressions are derived relating the effective wedge angle and orientation to the weighting and wedge angles of the orthogonal wedged field segments. This technique will be important when using multileaf collimator field shaping for which collimator rotation is dictated by target or critical structure shape and orientation. The term omni wedge is introduced to describe this technique.