Parallel beam optical tomography apparatus for 3-d radiation dosimetry

Nikola Krstajić, Simon J. Doran

    Research output: Chapter in Book/Report/Conference proceedingConference contribution


    Since the discovery of X rays radiotherapy has had the same aim - to deliver a precisely measured dose of radiation to a defined tumour volume with minimal damage to surrounding healthy tissue. Recent developments in radiotherapy such as intensity modulated radiotherapy (IMRT) can generate complex shapes of dose distributions. Until recently it has not been possible to verify that the delivered dose matches the planned dose. However, one often wants to know the real three-dimensional dose distribution. Three-dimensional radiation dosimeters have been developed since the early 1980s. Most chemical formulations involve a radiosensitive species immobilised in space by gelling agent. Magnetic Resonance Imaging (MRI) and optical techniques have been the most successful gel scanning techniques so far. Optical techniques rely on gels changing colour once irradiated. Parallel beam optical tomography has been developed at the University of Surrey since the late 1990s. The apparatus involves light emitting diode light source collimated to a wide (12cm) parallel beam. The beam is attenuated or scattered (depending on the chemical formulation) as it passes through the gel. Focusing optics projects the beam onto a CCD chip. The dosimeter sits on a rotation stage. The tomography scan involves continuously rotating the dosimeter and taking CCD images. Once the dosimeter has been rotated over 180 degrees the images are processed by filtered back projection. The work presented discusses the optics of the apparatus in more detail.

    Original languageEnglish
    Title of host publicationOpto-Ireland 2005
    Subtitle of host publicationImaging and Vision
    EditorsFionn D. Murtagh
    PublisherSPIE-International Society for Optical Engineering
    Number of pages8
    Publication statusPublished - 1 Jun 2005
    EventOpto-Ireland 2005: Imaging and Vision - Dublin, Ireland
    Duration: 5 Apr 20056 Apr 2005

    Publication series

    NameProceedings of SPIE - The International Society for Optical Engineering
    PublisherSociety of Photo-optical Instrumentation Engineers
    ISSN (Print)0277-786X


    ConferenceOpto-Ireland 2005: Imaging and Vision


    • Gel Dosimetry
    • Optical Tomography
    • Radiotherapy

    ASJC Scopus subject areas

    • Electrical and Electronic Engineering
    • Condensed Matter Physics


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