• Understanding how to display DICOM RT-Dose

    From Aram Rostamitabar@21:1/5 to johnw...@gmail.com on Sun Jul 11 01:24:24 2021
    On Friday, March 14, 2008 at 10:15:56 PM UTC+3:30, johnw...@gmail.com wrote:
    Hi all,
    I am trying to better understand the concepts behind DICOM RT-Dose
    objects, and how they should be displayed by viewing applications
    supporting DICOM RT objects.
    What I understood until now (correct me if I am wrong) is that doses
    can be expressed in terms of:
    1) dose points or isodose curves: in this case, the elements which
    should be displayed by a RT viewer application are described in the
    DICOM dataset through the ROI Contour module, which basically
    describes points, lines or polygons as a set of 3D coordinates in the
    3D space of the patient.
    2) does grid: in this second case, the dose values are described
    through the Pixel Data data element. Here, pixel values actually
    represent dose values, correct? A multi-frame Pixel Data attribute may
    be present, and in this case each frame represent dose values for a
    given "plane / slice", as specified by the "(300C,000C) - Grid Frame
    Offset Vector" data element.
    Is my understanding correct until now?
    Ok, now I have a question:
    I have some sample studies where multiple "RT-Dose" DICOM files are
    present, each one having multiple frames in Pixel Data. Considering
    all these RT-Dose DICOM files, I have several RT dose "pixel data"
    frames (coming from different files) which apply to a given CT slice
    (i.e., which belong to the same plane as the CT slice). Should I SUM
    the dose values coming from each RT dose frame which apply to a given
    CT slice in order to obtain the actual dose value which should be
    applied to every pixel of my CT slice? Or how should I combine values
    coming from different RT dose frames which apply to the same CT slice
    (i.e., which have the same Grid Frame Offset value)?
    In particular, I am considering the issue from the point of view of
    the viewing application: I have seen applications which show the RT
    dose which applies to each CT slice as a semi-transparent overlay area varying from blue for lower-dose zones to red for higher-dose zones (IsoShades). So in this case I guess the viewing application should
    compute the "overall" dose which applies to a given CT slice. How are
    the several RT-dose frames related to a given CT slice's plane
    combined?
    Any clarification would be greatly appreciated.
    Regards,
    John.
    Hi Dear John
    we need some information about your experiences for RT-DOSE and RT-PLAN
    how can convert Ct DICOM to RT-DOSE or the most important questions is how can we calculate the value of dose??
    Thanks.
    Aram

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