title: Orthovoltage applicator design: its effect on a transmission monitor chamber.
abstract: In the Pantak DXT300, the applicators are mounted immediately below a transmission monitor chamber. Changing the metals used in applicator construction can cause variations of up to 22% in calibration factor (cGy MU(-1)) and apparent dose rate (MU min(-1)), but has no effect on radiation dose rate (cGy min(-1)). The results are consistent with being caused by backscatter from the applicator to the monitor chamber.
authors.affiliation: Medical Physics Department, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Thomas
mesh_terms: D002138:Calibration; D006801:Humans; D011878:Radiotherapy / Q000295:instrumentation*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted