Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Exit dose studies in megavoltage photon therapy.

G D Lambert, W E Liversage, A M Hirst

    The British Journal of Radiology
    |May 1, 1983
    PubMed
    Summary

    The absence of back-scattering material near phantoms significantly reduces radiation dose measurements by up to 17%. Adding specific material restores electron back-scattering, minimizing dose discrepancies in radiation therapy dosimetry.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    Demonstration of an efficient, photonic-based astronomical spectrograph on an 8-m telescope.

    Optics express·2017
    Same author

    Low-temperature plasma treatment induces DNA damage leading to necrotic cell death in primary prostate epithelial cells.

    British journal of cancer·2015
    Same author

    Longitudinal target-spin asymmetries for deeply virtual compton scattering.

    Physical review letters·2015
    Same author

    Strangeness suppression of qq creation observed in exclusive reactions.

    Physical review letters·2014
    Same author

    Nuclear physics. Momentum sharing in imbalanced Fermi systems.

    Science (New York, N.Y.)·2014
    Same author

    Hard two-body photodisintegration of 3He.

    Physical review letters·2014

    Area of Science:

    • Medical Physics
    • Radiation Dosimetry
    • Radiotherapy

    Background:

    • Accurate dose measurement in radiotherapy is crucial for effective treatment.
    • Solid phantoms are used to simulate patient tissues for radiation dosimetry.
    • The absence of back-scattering material can affect ionization chamber readings.

    Purpose of the Study:

    • To investigate dose perturbations in solid phantoms due to the lack of back-scattering material.
    • To quantify the impact of missing back-scattered electrons and photons on ionization chamber measurements.
    • To determine the optimal thickness of material needed to restore back-scattering.

    Main Methods:

    • Utilized a coin-shaped ionization chamber positioned away from the radiation source.
    • Employed Cobalt-60 and 4, 8, and 16 MV X-ray beams.
    • Varied the presence and thickness of material behind the ionization chamber in solid phantoms.

    Main Results:

    • Ionization measurements were up to 17% lower without back-scattering material.
    • This reduction was attributed to the loss of back-scattered electrons and photons.
    • 1.0–2.7 mm of unit density material restored electron back-scattering, causing only a small dose reduction from lost photons.

    Conclusions:

    • The absence of back-scattering material significantly impacts ionization chamber dosimetry.
    • Restoring electron back-scattering is achievable with a thin layer of material.
    • Careful consideration of phantom scatter conditions is necessary for precise radiotherapy dose determination.

    Related Experiment Videos