d.b.a. 3D Dosimetry
  • QAbyMail™ Service
    for High-Definition 3D End-to-End QA
    in Radiation Therapy and Radiosurgery

    The CrystalBalls™ are radiochromic polymer gel dosimeters, sealed inside thin-wall glass spheres of standardized dimensions, approximating the size of a human head. ​ Self-developing.  Muscle-tissue equivalent.  Instant QA phantom setup.  No Cables.  No electronics. 

    Specifications:  isotropic voxel resolution down to (0.5mm)^3.  Dosimetric accuracy:  1% relative,  2% absolute. 

    For QA of:  SRS,  SBRT,  VMAT,  MR-Linac,  CyberKnife,  GammaKnife, Proton Therapy. 

    Ideal QA for single-isocenter VMAT of multiple brain metastases. 

    QAbyMail ™ Service:  Customers return exposed CrystalBalls and DICOM files to 3D Dosimetry Lab for laser CT scanning and QA analysis.  High-definition 3D QA reports are returned by email. They may be customized but normally include 3D gamma histograms & passing rates; voxel statistics for dose difference and distance-to-agreement; overlays of planned vs measured 3D and 2D isodoses, profiles and dose-volume histograms; detected shifts of the center of mass of the 3D dose cloud;  interactive 3D maps of dose difference, distance-to-agreement, and 3D gamma. 


    The CrystalBall™ mounted in a QA stand and ready for simulator CT


    The CrystalBall™ set up for Proton Therapy QA


    CrystalBall™ mounted in an SRS head frame

                                                                                                                                                                                                                                                                                                                                            EXAMPLE  RESULTS

    Coronal frontal view of overlaid 3D isodose surfaces (VMAT of six brain metastases, PTV#4)


    Overlay of 2D (sagittal left) isodose lines (VMAT of six brain metastases, PTV#4)


    Overlay of I-S profiles (VMAT of six brain metastases, PTV#4)

    3D gamma

    3D gamma volume histogram for PTV#4 (VMAT of six brain metastases)


    CrystalBall™ 3D QA report summary for one PTV in a six brain-metastases VMAT

    Proton Therapy QA

    Proton PBS IMPT. (a) 3D isodose surfaces at 50% dose level. Red - plan, blue - measurement; (b) Coronal isodoses. Solid - plan, dotted - measurement. (c) I-S profile overlay. Red - plan, blue - measurement, yellow - dose difference, magenta - DTA, cyan - 3D gamma.

The Crystal Ball™ End-to-End QA detects and measures any and all clinically significant cumulative errors 
that may originate anywhere during radiation therapy or radiosurgery planning and delivery process
and are located anywhere within the treated volume.