Film dosimetry studies for patient specific quality assurance in microbeam radiation therapy.

Item request has been placed! ×
Item request cannot be made. ×
loading   Processing Request
Read More Add to Saved list
  • Additional Information
    • Source:
      Publisher: Istituti Editoriali e Poligrafici Internazionali Country of Publication: Italy NLM ID: 9302888 Publication Model: Print Cited Medium: Internet ISSN: 1724-191X (Electronic) Linking ISSN: 11201797 NLM ISO Abbreviation: Phys Med Subsets: MEDLINE
    • Publication Information:
      Publication: Pisa : Istituti Editoriali e Poligrafici Internazionali
      Original Publication: Lugano, Switzerland : Giardini editori S.A.,
    • Subject Terms:
      Film Dosimetry/*methods ; Radiotherapy/*methods; Brain Neoplasms/radiotherapy ; Dose Fractionation, Radiation ; Humans ; Phantoms, Imaging ; Radiometry/methods ; Radiotherapy Dosage ; Synchrotrons ; X-Rays
    • Abstract:
      Microbeam radiation therapy (MRT) uses synchrotron arrays of X-ray microbeams to take advantage of the spatial fractionation effect for normal tissue sparing. In this study, radiochromic film dosimetry was performed for a treatment where MRT is introduced as a dose boost in a hypofractionated stereotactic radiotherapy (SRT) scheme. The isocenter dose was measured using an ionization chamber and two dimensional dose distributions were determined using radiochromic films. To compare the measured dose distribution to the MRT treatment plan, peak and valley were displayed in separate dosemaps. The measured and computed isocenter doses were compared and a two-dimensional 2%/2 mm normalized γ-index analysis with a 90% passing rate criterion was computed. For SRT, a difference of 2.6% was observed in the dose at the isocenter from the treatment plan and film measurement, with a passing rate of 96% for the γ-index analysis. For MRT, peak and valley doses differences of 25.6% and 8.2% were observed, respectively but passing rates of 96% and 90% respectively were obtained from the normalized γ-index maps. The differences in isocenter doses measured in MRT should be further investigated. We present the methodology of patient specific quality assurance (QA) for studying MRT dose distributions and discuss ideas to improve absolute dosimetry. This patient specific QA will be used for large animal trials quality assurance where MRT will be administered as a dose boost in conventional SRT. The observed remaining discrepancies should be studied against approximations in the TPS phantom materials, beams characteristics or film read-out procedures.
      (Copyright © 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)
    • Contributed Indexing:
      Keywords: Film dosimetry; Microbeam radiation therapy; Quality assurance
    • Publication Date:
      Date Created: 20191002 Date Completed: 20191015 Latest Revision: 20191015
    • Publication Date:
      20231215
    • Accession Number:
      10.1016/j.ejmp.2019.09.071
    • Accession Number:
      31574356