title: On-line portal imaging: computer-assisted error measurement.
abstract: A microcomputer-based system was implemented in an on-line portal imaging system to determine portal misalignment in radiation therapy. Reference markers derived from a patient simulation film are superposed on the daily on-line portal images for visual evaluation of placement accuracy. The ability to check the alignment after administration of 3-6 cGy of radiation and the minimal operator interaction required make this system useful in radiation therapy delivery.
authors.affiliation: Department of Radiation Oncology, Johns Hopkins Oncology Center, Baltimore, MD 21205.
authors.forename: W C
authors.initials: WC
authors.lastname: Lam
authors.forename: M G
authors.initials: MG
authors.lastname: Herman
authors.forename: K S
authors.initials: KS
authors.lastname: Lam
authors.forename: D J
authors.initials: DJ
authors.lastname: Lee
mesh_terms: D008433:Mathematics; D011880:Radiotherapy Planning, Computer-Assisted