title: Linear-accelerator X-ray output: a multicentre chamber-based intercomparison study in Australia and New Zealand.
abstract: This paper describes the process and results of a survey of linear accelerator outputs as part of an Australasian Level III Dosimetry Intercomparison. This study involved the measurement of accelerator output under reference conditions ('Level I') with a small-volume ionisation chamber in water for 47 beams at 36 radiotherapy centres using the IAEA TRS 398 dose-to-water protocol. The mean ratio of measured to locally-determined accelerator output was 1.003 +/- 0.009 (1 standard deviation) with a range from 0.981 to 1.024. No correlation could be found between output ratio and accelerator type or local output calibration protocol. The small-volume chamber used satisfied most requirements for the study though showed some variation in sensitivity via repeated cross-calibration with a chamber calibrated at a primary standards laboratory.
authors.affiliation: Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia. Martin.Ebert@health.wa.gov.au
authors.forename: M A
authors.initials: MA
authors.lastname: Ebert
authors.forename: S J
authors.initials: SJ
authors.lastname: Howlett
authors.forename: K
authors.initials: K
authors.lastname: Harrison
authors.forename: D
authors.initials: D
authors.lastname: Cornes
authors.forename: C S
authors.initials: CS
authors.lastname: Hamilton
authors.forename: J D
authors.initials: JD
authors.lastname: Denham
mesh_terms: D001315:Australia; D019544:Equipment Failure Analysis / Q000706:statistics & numerical data*; D009520:New Zealand; D010315:Particle Accelerators / Q000592:standards* / Q000706:statistics & numerical data*; D011785:Quality Assurance, Health Care; D011874:Radiometry / Q000295:instrumentation* / Q000592:standards* / Q000706:statistics & numerical data; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014965:X-Rays