Premium
Intra‐ and interfractional patient motion for a variety of immobilization devices
Author(s) -
Engelsman Martijn,
Rosenthal Stanley J.,
Michaud Susan L.,
Adams Judith A.,
Schneider Robert J.,
Bradley Stephen G.,
Flanz Jacob B.,
Kooy Hanne M.
Publication year - 2005
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 - 10.1118/1.2089507
Subject(s) - variety (cybernetics) , medical physics , medical imaging , medicine , computer science , radiology , artificial intelligence
The magnitude of inter‐ and intrafractional patient motion has been assessed for a broad set of immobilization devices. Data was analyzed for the three ordinal directions—left–right ( x ) , sup–inf ( y ) , and ant–post ( z ) —and the combined spatial displacement. We have defined “rigid” and “nonrigid” immobilization devices depending on whether they could be rigidly and reproducibly connected to the treatment couch or not. The mean spatial displacement for intrafractional motion for rigid devices is 1.3 mm compared to 1.9 mm for nonrigid devices. The modified Gill–Thomas–Cosman frame performed best at controlling intrafractional patient motion, with a 95% probability of observing a three‐dimensional (3D) vector length of motion ( v 95 ) of less than 1.8 mm, but could not be evaluated for interfractional motion. All other rigid and nonrigid immobilization devices had av 95of more than 3 mm for intrafractional patient motion. Interfractional patient motion was only evaluated for the rigid devices. The mean total interfractional displacement was at least 3.0 mm for these devices whilev 95was at least 6.0 mm.