title: Imaging practices and radiation doses from imaging in radiotherapy.
abstract: Modern radiotherapy treatments require frequent imaging for accurate patient positioning relative to the therapeutic radiation beam. Imaging practices in five Finnish radiotherapy clinics were assessed and discussed from the patient dose optimization point of view. The results show that imaging strategies are not jointly established and variations exist. The organ absorbed doses depend on imaging technique and imaging frequency. In particular, organ doses from the cone beam computed tomography can have very large variations (a factor of 10-50 in breast imaging and factor of 5 in prostate imaging). The cumulative imaging organ dose from the treatment can vary by a factor of ten or more for the same treatment, depending on the chosen technique and imaging frequency. Awareness and optimization of the imaging dose in image-guided radiotherapy should be strengthened.
authors.affiliation: STUK - Radiation and Nuclear Safety Authority, P.O. Box 14, FI-00881 Helsinki, Finland. Electronic address: teemu.siiskonen@stuk.fi.
authors.forename: Teemu
authors.initials: T
authors.lastname: Siiskonen
authors.affiliation: STUK - Radiation and Nuclear Safety Authority, P.O. Box 14, FI-00881 Helsinki, Finland.
authors.forename: Sampsa
authors.initials: S
authors.lastname: Kaijaluoto
authors.affiliation: University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland.
authors.forename: Tudor
authors.initials: T
authors.lastname: Florea
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy / Q000601:surgery; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation / Q000379:methods; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D008408:Mastectomy; D008953:Models, Anatomic; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D011795:Surveys and Questionnaires
keywords: IGRT; Imaging; Out-of-field dose; Radiotherapy