title: Dosimetric evaluation of a 2D pixel ionization chamber for implementation in clinical routine.
abstract: In this paper we present the results of a dosimetric evaluation of a 2D ionization chamber array with the objective of its implementation for quality assurance in clinical routine. The pixel ionization chamber MatriXX (Scanditronix Wellhofer, Germany) consists of 32x32 chambers with a distance of 7.6 mm between chamber centres. The effective depth of measurement under the surface of the detector was determined. The dose and energy dependence, the behaviour of the device during its initial phase and its time stability as well as the lateral response of a single chamber of the detector in cross-plane and diagonal directions were analysed. It could be shown, that the detector's response is linear with dose and energy independent. Taking the lateral response into account, two different dose profiles, for a pyramidal and an IMRT dose distribution, were applied to compare the data generated by a treatment planning system with measurements. From these investigations it can be concluded that the detector is a suitable device for quality assurance and 2D dose verifications.
authors.affiliation: Department of Radiotherapy and Radio-Oncology, Center for Diagnostic Imaging and Image Guided Therapy, Radiological Physics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, DE-20251 Hamburg, Germany. j.herzen@uke.uni-hamburg.de
authors.forename: J
authors.initials: J
authors.lastname: Herzen
authors.forename: M
authors.initials: M
authors.lastname: Todorovic
authors.forename: F
authors.initials: F
authors.lastname: Cremers
authors.forename: V
authors.initials: V
authors.lastname: Platz
authors.forename: D
authors.initials: D
authors.lastname: Albers
authors.forename: A
authors.initials: A
authors.lastname: Bartels
authors.forename: R
authors.initials: R
authors.lastname: Schmidt
mesh_terms: D004867:Equipment Design; D006801:Humans; D010315:Particle Accelerators / Q000295:instrumentation*; D011786:Quality Control; D011839:Radiation, Ionizing; D011879:Radiotherapy Dosage / Q000592:standards; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy / Q000592:standards*; D012680:Sensitivity and Specificity