title: Deconvolution of detector size effect for small field measurement.
abstract: Parametrization of the small fields employed in stereotactic applications is a painstaking process involving extensive film dosimetry to achieve acceptable beam edge definition. Use of cylindrical or spherical detectors for profile measurements would simplify data acquisition but add a volume averaging artifact to beam edge definition. We demonstrate a simple approach to unfolding the chamber size artifact from measured small beam profiles using typical cylindrical chambers. In comparison with film measurements we have found good agreement when the detector response function is deconvoluted from the measured profiles, although the amount of correction needed is fairly minimal for the detectors studied.
authors.affiliation: University of Minnesota, Department of Therapeutic Radiology, Minneapolis 55455-0110, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: Higgins
authors.forename: C H
authors.initials: CH
authors.lastname: Sibata
authors.forename: L
authors.initials: L
authors.lastname: Siskind
authors.forename: J W
authors.initials: JW
authors.lastname: Sohn
mesh_terms: D005373:Film Dosimetry; D006801:Humans; D008433:Mathematics; D019047:Phantoms, Imaging; D016634:Radiosurgery / Q000295:instrumentation* / Q000379:methods*; D013238:Stereotaxic Techniques