title: Quality assurance of electron beams using a Varian electronic portal imaging device.
abstract: The feasibility of utilizing an electronic portal imaging device (EPID) for the quality assurance of electron beams was investigated. This work was conducted on a Varian 2100iX machine equipped with an amorphous silicon (aS1000) portal imager. The linearity of the imager pixel response as a function of exposed dose was first confirmed. The short-term reproducibility of the EPID response to electron beams was verified. Low (6 MeV), medium (12 MeV) and high (20 MeV) energies were tested, each along with small (6 × 6 cm(2)), medium (10 × 10 cm(2)) and large (20 × 20 cm(2)) applicators. Acquired EPID images were analyzed using an in-house MATLAB code for radiation field size, penumbra, symmetry and flatness. Field sizes and penumbra values agreed with those from film dosimetry to within 1 mm. Field symmetry and flatness constancies were measured over a period of three weeks. The results indicate that EPID can be used for routine quality assurance of electron beams.
authors.affiliation: Department of Radiation Physics, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. yinkun.wang@rmp.uhn.on.ca
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: R
authors.initials: R
authors.lastname: Heaton
authors.forename: B
authors.initials: B
authors.lastname: Norrlinger
authors.forename: M
authors.initials: M
authors.lastname: Islam
mesh_terms: D003952:Diagnostic Imaging / Q000295:instrumentation*; D055615:Electrical Equipment and Supplies; D005240:Feasibility Studies; D011786:Quality Control; D011829:Radiation Dosage